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Dietary supplement

Herbal Cal Ingredients & Drug Interactions

by New Sun

Herbal Cal label
See full label image
Capsule Category: Botanical With Nutrients
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Herbal Cal against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Major

Herbal Cal is a dietary supplement by New Sun with 9 active ingredients. Its ingredients are commonly taken for bone health and osteoporosis prevention, dietary calcium deficiency, heartburn relief (calcium carbonate antacids).Based on those ingredients, 2,269 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Marshmallow, Slippery Elm, Valerian. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Herbal Cal by New Sun

Ask about any prescription or over-the-counter medication and we check it for interactions with Herbal Cal by New Sun — and tell you which ingredient is responsible.

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Computed from our clinical databases

HelloPharmacist Scorecard of Herbal Cal by New Sun

Four independent checks of what is known — a summary of the available information, not a grade of the product itself.

Evidence for Intended Use
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not assessable

The stated purpose hasn't been mapped to our evidence data yet.

Why this rating?
  • We haven't mapped this product's purpose to our evidence data yet — it'll be graded on the next content refresh.
Ingredient Transparency
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 1 of its 9 active ingredients.
  • “Proprietary Blend” is a proprietary blend — the label gives one combined amount (1,260 mg) without saying how much of each component you get.
Known Interaction Concern
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 9 of the 9 matched ingredients can interact with medications — Alfalfa, Comfrey, Marshmallow, Calcium, Oats, among others.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; diabetes medications; heart-rhythm medications; lithium.
  • For scale: 2,270 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.
Safety Information
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 8 of the 9 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 9 of 9.
  • General safety write-ups exist for 9 of 9.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

HelloPharmacist summaryFormula with limited ingredient disclosure with no assessable stated purpose. Major medication interactions have been identified, and safety information is well characterized.

Assessment coverage: 9 of 9 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Oct 1, 2012.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Herbal Cal, straight from the product label.

Brand New Sun
Barcode (UPC) 61-9
Net contents 100 Capsule(s)
Market status Off market
Date entered into DSLD Oct 1, 2012
DSLD ID 11895
Product type Botanical With Nutrients
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Herbal Cal by New Sun, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
3 Capsule(s)
Maximum serving Sizes:
3 Capsule(s)
Servings per container
33
UPC/BARCODE
61-9
IngredientAmount% DV
Calcium12 mg1%
Proprietary Blend1260 mg--
Slippery Elm0 NP--
Marshmallow0 NP--
Horsetail0 NP--
Valerian0 NP--
Alfalfa0 NP--
Comfrey0 NP--
Oat Straw0 NP--
Irish Moss0 NP--

Other ingredients: Gelatin, Cellulose, Magnesium Stearate

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
General

Product No. 61-9 V3.0

Suggested/Recommended/Usage/Directions

Recommendation: As a dietary supplement, take three capsules with two meals daily.

Precautions

Do not use of safety seal is missing or broken.

Keep out of reach of children.

Warning: Do not use if you suffer from cardiac or renal dysfunction.

Do not use if pregnant or nursing. If you are takiing any medications or experiencing health issues, consult your doctor before use.

Storage

Store in a cool, dry place.

FDA Disclaimer Statement

This prodict is not intended to diagnose, treat, cure, or prevent any disease.

FDA Statement of Identity

Dietary Supplement

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Herbal Cal by New Sun label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Herbal Cal label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Herbal Cal by New Sun

These are the 9 active ingredients this product is made of. Select any to open its full monograph.

Serving size3 Capsule(s) Dosage formCapsule Servings per container33 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Calcium

Interacts with
168 drugs
12 mg per serving

Calcium is an essential mineral your body needs for strong bones, nerve signaling, and muscle function, and supplements can help fill gaps when diet f...

Calcium monograph & interactions

Proprietary Blend

1260 mg per serving

Other (inactive) ingredients: Gelatin, Cellulose, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Herbal Cal by New Sun Drug Interactions

Herbal Cal contains 9 ingredients, and 9 of them have known drug interactions. Altogether they interact with 2,269 medications. Here’s the picture, then you can look up your own drug.

Want to check YOUR meds against Herbal Cal?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
2,269Drugs
9 Major 2,205 Moderate 55 Minor

Ingredients driving the most interactions

Marshmallow 2,040
Slippery Elm 2,022
Valerian 902
Alfalfa 583
Comfrey 438

Individual Drug Interactions

The ingredients in Herbal Cal interact with 2,269 drugs. Click any drug to see the details.

9 of the 9 ingredients in Herbal Cal interact with drugs. Each result below shows which ingredient is responsible. Marshmallow Slippery Elm Valerian Alfalfa Comfrey Horsetail Calcium Oat Straw Irish Moss

Each ingredient & the kinds of drugs it affects

For each ingredient in Herbal Cal with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Marshmallow3 drug types · 2,040 drugs

Lithium

Theoretically, due to potential diuretic effects, marshmallow might reduce excretion and increase levels of lithium.
Marshmallow is thought to have diuretic properties. To avoid lithium toxicity, the dose of lithium might need to be decreased when used with marshmallow.

Likelihood Probable Evidence D
Anticoagulant/Antiplatelet Drugs

Theoretically, marshmallow flower might have antiplatelet effects.
Animal research suggests that marshmallow flower extract has antiplatelet effects. However, the root and leaf of marshmallow, not the flower, are the plant parts most commonly found in dietary supplements. Theoretically, use of marshmallow flower with anticoagulant/antiplatelet drugs can have additive effects, and might increase the risk for bleeding in some patients.

Likelihood Unlikely Evidence D
Oral Drugs

Theoretically, mucilage in marshmallow might impair absorption of oral drugs.
Marshmallow contains mucilage which can affect oral drug absorption. To avoid changes in absorption, take marshmallow 30-60 minutes after oral medications.

Likelihood Possible Evidence D
Marshmallow full monograph & interactions

Slippery Elm1 drug type · 2,022 drugs

Oral Drugs

Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Slippery elm inner bark contains mucilage, which may interfere with the absorption of orally administered drugs.

Likelihood Possible Evidence D
Slippery Elm full monograph & interactions

Valerian6 drug types · 902 drugs

Alcohol (Ethanol)

Valerian can have additive sedative effects when used concomitantly with alcohol.
Valerian has sedative effects. Theoretically, valerian might have an additive sedative effect when combined with alcohol. Excessive sedation has been reported in an alcohol-abusing individual who took valerian and Gingko biloba. However, the potential interaction between valerian and alcohol has been disputed in other research. Limited evidence suggests that a combination of valerian 160 mg and lemon balm 80 mg (Euvegal) does not cause further deterioration in reaction ability and reaction rate when taken with alcohol as compared to the effects of alcohol alone.

Likelihood Possible Evidence B
Alprazolam (Xanax)

Valerian can have additive sedative effects when used with alprazolam. Also, valerian in high doses might modestly increase alprazolam levels, though this is not likely to be clinically significant.
Valerian has sedative effects. Theoretically, valerian might cause additive sedation when combined with alprazolam. Also, a small pharmacokinetic study shows that taking valerian extract 1000 mg daily (providing 11 mg valerenic acid) might increase alprazolam levels by about 19%. This might be due to valerian's mild inhibition of cytochrome P450 3A4 (CYP3A4). Despite being statistically significant, this increase is not likely to be clinically significant.

Likelihood Possible Evidence B
Cns Depressants

Valerian can have additive sedative effects when used concomitantly with CNS depressant drugs.
Theoretically, concomitant use of valerian and drugs with sedative and anesthetic properties may cause additive therapeutic and adverse effects.

Likelihood Possible Evidence D
Glucuronidated Drugs

Valerian might weakly inhibit glucuronidation and increase concentrations of drugs metabolized by UGT1A1 and UGT2B7.
In vitro research shows that methanolic valerian extract and valerenic acid might competitively inhibit UDP-glucuronosyltransferase (UGT) 1A1 (UGT1A1) and UGT2B7.

Likelihood Possible Evidence D
Cytochrome P450 2D6 (Cyp2D6) Substrates

Valerian does not seem to have a clinically relevant effect on levels of drugs metabolized by CYP2D6.
Although some in vitro evidence suggests that valerian affects CYP2D6, clinical pharmacokinetic (PK) studies show that valerian is unlikely to affect the CYP2D6 enzyme. In one PK study, taking valerian 1000 mg (providing about 11 mg valerenic acid) nightly for 14 days did not affect the metabolism of dextromethorphan, a CYP2D6 substrate. In another PK study, taking valerian 125 mg three times daily for 28 days did not affect metabolism of debrisoquine, an accepted CYP2D6 probe-substrate.

Likelihood Unlikely Evidence B
Cytochrome P450 3A4 (Cyp3A4) Substrates

Valerian does not seem to have a clinically relevant effect on levels of drugs metabolized by CYP3A4.
Although some in vitro evidence suggests that valerian extract might inhibit or induce CYP3A4, clinical pharmacokinetic (PK) studies show that valerian does not have a clinically significant effect on the CYP3A4 enzyme. In one PK study, taking valerian 125 mg three times daily for 28 days did not affect metabolism of midazolam, an accepted CYP3A4 probe-substrate. In another PK study, taking valerian 1000 mg (providing about 11 mg valerenic acid) nightly for 14 days modestly increases levels of alprazolam, a CYP3A4 substrate, suggesting mild inhibition of CYP3A4. However, this mild inhibition is unlikely to be clinically relevant.

Likelihood Possible Evidence B
Valerian full monograph & interactions

Alfalfa6 drug types · 583 drugs

Warfarin (Coumadin)

Theoretically, alfalfa might reduce the anticoagulant activity of warfarin.
Alfalfa contains a large amount of vitamin K. This could theoretically interfere with the activity of warfarin.

Likelihood Probable Evidence D
Antidiabetes Drugs

Theoretically, alfalfa might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Animal research suggests that alfalfa decreases blood sugar in diabetic mice. Also, in one case report, a diabetic patient experienced hypoglycemia after consuming alfalfa extract. Monitor blood glucose levels closely. Dose adjustments might be necessary.

Likelihood Possible Evidence D
Contraceptive Drugs

Theoretically, alfalfa might interfere with the activity of contraceptive drugs.
Alfalfa contains coumestrol, a phytoestrogen, and isoflavonoids, which have estrogenic effects.

Likelihood Possible Evidence D
Estrogens

Theoretically, alfalfa might interfere with hormone therapy.
Alfalfa contains coumestrol, a phytoestrogen, and isoflavonoids, which have estrogenic effects.

Likelihood Possible Evidence D
Immunosuppressants

Theoretically, alfalfa might decrease the efficacy of immunosuppressive therapy.
In vitro research and human case reports suggest that alfalfa may have immunostimulant effects.

Likelihood Possible Evidence D
Photosensitizing Drugs

Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Animal research suggests that excessive doses of alfalfa may increase photosensitivity, possibly due to its chlorophyll content. It is unclear if this effect would be clinically relevant in humans.

Likelihood Possible Evidence D
Alfalfa full monograph & interactions

Comfrey2 drug types · 438 drugs

Cytochrome P450 3A4 (Cyp3A4) Inducers

Theoretically, CYP3A4 inducers might increase the risk of adverse effects from the pyrrolizidine alkaloid constituents in comfrey.
CYP3A4 enzymes convert pyrrolizidine alkaloids, constituents of comfrey, to toxic metabolites. Some case reports show that enzyme inducers, such as phenobarbital, seem to enhance the toxicity of comfrey.

Likelihood Possible Evidence D
Hepatotoxic Drugs

Theoretically, comfrey might have additive adverse effects on the liver when used with hepatotoxic drugs.
Due to its pyrrolizidine alkaloid constituents, comfrey can cause hepatotoxic effects, including ascites, cirrhosis, hepatic fibrosis, hepatomegaly, and sinusoidal obstruction syndrome.

Likelihood Possible Evidence D
Comfrey full monograph & interactions

Horsetail5 drug types · 188 drugs

Antidiabetes Drugs

Theoretically, taking horsetail with antidiabetes drugs might increase the risk of hypoglycemia.
Equisetum myriochaetum has demonstrated hypoglycemic activity in clinical research. In an animal diabetic model, Equisetum giganteum had hypoglycemic effects. It is unclear whether other horsetail species have hypoglycemic effects.

Likelihood Possible Evidence D
Diuretic Drugs

Theoretically, taking horsetail with diuretic drugs might increase potassium loss and the risk of hypokalemia.
Laboratory research shows that various species of horsetail have diuretic properties. Due to its diuretic effects, there has been concern that taking horsetail along with potassium-depleting diuretics might increase the risk for hypokalemia. However, pharmacokinetic research in humans shows that taking horsetail 900 mg daily for 4 days does not affect urinary excretion of electrolytes, including potassium and sodium, despite having a diuretic effect similar to taking hydrochlorothiazide 25 mg daily. It is unclear if taking horsetail for a longer duration would affect electrolyte levels. Until more is known, use with caution.

Likelihood Possible Evidence D
Efavirenz (Sustiva)

Theoretically, horsetail might decrease the levels and clinical effects of efavirenz.
In two case reports, patients were found to have detectable viral loads when taking horsetail-containing supplements along with an antiretroviral regimen that included efavirenz. In one case, the antiretroviral regimen included zidovudine, lamivudine, and efavirenz; in the other case, the regimen consisted of emtricitabine, tenofovir disoproxil fumarate, and efavirenz. One month after discontinuing horsetail, the viral loads became undetectable in both cases. The exact mechanism of this interaction is unknown. It is also unclear if this interaction is specific to efavirenz or if it is related to various components of antiretroviral therapy.

Likelihood Possible Evidence D
Lithium

Theoretically, horsetail might increase the levels and adverse effects of lithium.
Animal research suggests that horsetail has diuretic properties. Theoretically, due to these potential diuretic effects, horsetail might reduce excretion and increase levels of lithium. The dose of lithium might need to be decreased.

Likelihood Possible Evidence D
Nucleoside Reverse Transcriptase Inhibitors (Nrtis)

Theoretically, horsetail might decrease the levels and clinical effects of NRTIs.
In two case reports, patients were found to have detectable viral loads when taking horsetail-containing supplements along with an antiretroviral therapy. In one case, the antiretroviral regimen included zidovudine, lamivudine, and efavirenz; in the other case, the regimen consisted of emtricitabine, tenofovir disoproxil fumarate, and efavirenz. One month after discontinuing the supplement, the viral loads became undetectable in both cases. The exact mechanism of these interactions is unknown. It is also unclear if these interactions are specific to NRTIs or if they are related to various components of antiretroviral therapy.

Likelihood Possible Evidence D
Horsetail full monograph & interactions

Calcium18 drug types · 168 drugs

Ceftriaxone (Rocephin)

Co-administration of intravenous calcium and ceftriaxone can result in precipitation of a ceftriaxone-calcium salt in the lungs and kidneys.
Avoid administering intravenous calcium in any form, such as parenteral nutrition or Lactated Ringers, within 48 hours of intravenous ceftriaxone. Case reports in neonates show that administering intravenous ceftriaxone and calcium can result in precipitation of a ceftriaxone-calcium salt in the lungs and kidneys. In several cases, neonates have died as a result of this interaction. So far there are no reports in adults; however, there is still concern that this interaction might occur in adults.

Likelihood Probable Evidence D
Dolutegravir (Tivicay)

Calcium seems to reduce levels of dolutegravir.
Advise patients to take dolutegravir either 2 hours before or 6 hours after taking calcium supplements. Pharmacokinetic research suggests that taking calcium carbonate 1200 mg concomitantly with dolutegravir 50 mg reduces plasma levels of dolutegravir by almost 40%. Calcium appears to decrease levels of dolutegravir through chelation.

Likelihood Probable Evidence B
Elvitegravir (Vitekta)

Calcium seems to reduce levels of elvitegravir.
Advise patients to take elvitegravir either 2 hours before or 2 hours after taking calcium supplements. Pharmacokinetic research suggests that taking calcium along with elvitegravir can reduce blood levels of elvitegravir through chelation.

Likelihood Probable Evidence B
Aluminum

Calcium citrate might increase aluminum absorption and toxicity. Other types of calcium do not increase aluminum absorption.
Calcium citrate can increase the absorption of aluminum when taken with aluminum hydroxide. The increase in aluminum levels may become toxic, particularly in individuals with kidney disease. However, the effect of calcium citrate on aluminum absorption is due to the citrate anion rather than calcium cation. Calcium acetate does not appear to increase aluminum absorption.

Likelihood Possible Evidence B
Bictegravir/Emtricitabine/Tenofovir Alafenamide (Biktarvy)

Calcium might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption when taken in a fasting state.
Advise patients that bictegravir/emtricitabine/tenofovir alafenamide and calcium can be taken together if taken with food. However, if taken on an empty stomach, bictegravir/emtricitabine/tenofovir alafenamide should not be taken with, or 2 hours after, calcium containing products.

Likelihood Probable Evidence D
Bisphosphonates

Calcium reduces the absorption of bisphosphonates.
Advise patients to take bisphosphonates at least 30 minutes before calcium, but preferably at a different time of day. Calcium supplements decrease absorption of bisphosphonates.

Likelihood Probable Evidence C
Calcipotriene (Dovonex)

Taking calcipotriene with calcium might increase the risk for hypercalcemia.
Calcipotriene is a vitamin D analog used topically for psoriasis. It can be absorbed in sufficient amounts to cause systemic effects, including hypercalcemia. Theoretically, combining calcipotriene with calcium supplements might increase the risk of hypercalcemia.

Likelihood Possible Evidence B
Digoxin (Lanoxin)

Using intravenous calcium with digoxin might increase the risk of fatal cardiac arrhythmias.
Hypercalcemia increases the risk of fatal cardiac arrhythmias with digoxin. However, one retrospective analysis of clinical data suggests that intravenous calcium does not increase the risk of dysrhythmias or mortality in patients receiving digoxin.

Likelihood Possible Evidence B
Diltiazem (Cardizem, Others)

Theoretically, calcium may reduce the therapeutic effects of diltiazem.
Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation. Theoretically, calcium might increase this risk of hypercalcemia and reduce the effectiveness of diltiazem.

Likelihood Probable Evidence D
Levothyroxine (Synthroid, Others)

Calcium seems to reduce the absorption and effectiveness of levothyroxine.
Advise patients to take levothyroxine and calcium supplements at least 4 hours apart. Calcium reduces levothyroxine absorption, probably by forming insoluble complexes. Calcium carbonate supplements reduce effectiveness of levothyroxine in patients with hypothyroidism.

Likelihood Probable Evidence B
Lithium

Theoretically, concomitant use of calcium and lithium may increase this risk of hypercalcemia.
Clinical research suggests that long-term use of lithium may cause hypercalcemia in 10% to 60% of patients. Theoretically, concomitant use of lithium and calcium supplements may further increase this risk.

Likelihood Possible Evidence B
Quinolone Antibiotics

Calcium seems to reduce the absorption of quinolone antibiotics.
Advise patients to take oral quinolones at least 2 hours before or 4-6 hours after calcium supplements or calcium-fortified foods. Taking calcium at the same time as oral quinolones can reduce quinolone absorption. Calcium binds to quinolones in the gut.

Likelihood Probable Evidence B
Raltegravir (Isentress)

Calcium may reduce levels of raltegravir.
Pharmacokinetic research shows that taking a single dose of calcium carbonate 3000 mg along with raltegravir 400 mg twice daily modestly decreases the mean area under the curve of raltegravir, but the decrease does not necessitate a dose adjustment of raltegravir. However, a case of elevated HIV-1 RNA levels and documented resistance to raltegravir has been reported for a patient taking calcium carbonate 1 gram three times daily plus vitamin D3 (cholecalciferol) 400 IU three times daily in combination with raltegravir 400 mg twice daily for 11 months. It is thought that calcium reduced raltegravir levels by chelation, leading to treatment failure.

Likelihood Possible Evidence B
Sotalol (Betapace)

Calcium seems to reduce the absorption of sotalol.
Advise patients to separate doses by at least 2 hours before or 4-6 hours after calcium. Calcium appears to reduce the absorption of sotalol, probably by forming insoluble complexes.

Likelihood Possible Evidence B
Tetracycline Antibiotics

Calcium seems to reduce the absorption of tetracycline antibiotics.
Advise patients to take oral tetracyclines at least 2 hours before, or 4-6 hours after calcium supplements. Taking calcium at the same time as oral tetracyclines can reduce tetracycline absorption. Calcium binds to tetracyclines in the gut.

Likelihood Probable Evidence C
Thiazide Diuretics

Taking calcium along with thiazides might increase the risk of hypercalcemia and renal failure.
Thiazides reduce calcium excretion by the kidneys. Using thiazides along with moderately large amounts of calcium carbonate increases the risk of milk-alkali syndrome (hypercalcemia, metabolic alkalosis, renal failure). Patients may need to have their serum calcium levels and/or parathyroid function monitored regularly.

Likelihood Probable Evidence C
Verapamil (Calan, Others)

Theoretically, calcium may reduce the therapeutic effects of verapamil.
Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation. Theoretically, use of calcium supplements may increase this risk of hypercalcemia and reduce the effectiveness of verapamil.

Likelihood Probable Evidence D
Calcium Channel Blockers

Intravenous calcium may decrease the effects of calcium channel blockers; oral calcium is unlikely to have this effect.
Intravenous calcium is used to decrease the effects of calcium channel blockers in the management of overdose. Intravenous calcium gluconate has been used before intravenous verapamil (Isoptin) to prevent or reduce the hypotensive effects without affecting the antiarrhythmic effects. But there is no evidence that dietary or supplemental calcium when taken orally interacts with calcium channel blockers.

Likelihood Unlikely Evidence D
Calcium full monograph & interactions

Oat Straw2 drug types · 86 drugs

Antidiabetes Drugs

Theoretically, oats may have additive effects with antidiabetic agents and might increase the risk of hypoglycemia.
Consuming oats can decrease blood glucose in patients with diabetes. In those who require insulin, taking oats 100 grams daily for 2 days reduces the insulin dose required to achieve metabolic control.

Likelihood Possible Evidence D
Insulin

Concomitant use of oats and insulin might increase the risk of hypoglycemia.
In patients with insulin-dependent type 2 diabetes, taking oats 100 grams daily for 2 days reduces the insulin dose required to achieve metabolic control.

Likelihood Possible Evidence B
Oat Straw full monograph & interactions

Irish Moss3 drug types · 22 drugs

Amiodarone (Cordarone)

Theoretically, combining sea moss with amiodarone might cause excessively high iodine levels.
Amiodarone contains 37.3% iodine and can increase iodine levels. Concomitant use with sea moss, which contains approximately 4-7 mcg of iodine per gram, might increase the risk of adverse effects from iodine, including altered thyroid function.

Likelihood Possible Evidence D
Antithyroid Drugs

Due to its iodine content, sea moss might alter the effects of antithyroid drugs.
Sea moss contains approximately 4-7 mcg of iodine per gram. Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking sea moss could theoretically alter the effects of antithyroid drugs.

Likelihood Possible Evidence D
Thyroid Hormone

Due to its iodine content, sea moss might alter the effects of thyroid hormone.
Sea moss contains approximately 4-7 mcg of iodine per gram. Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking sea moss could theoretically alter the effects of thyroid hormone.

Likelihood Possible Evidence D
Irish Moss full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Herbal Cal, from the product label.

New Sun

See all New Sun products
Name
New Sun
City
Hendersonville
State
NC
ZipCode
28792
Phone Number
1-800-544-0777
Web Address
www.newsun.net
Pharmacist Counseling Corner

Herbal Cal by New Sun: Common Questions

Does Herbal Cal by New Sun interact with any medications?
Yes. Based on its ingredients, Herbal Cal has a known interaction with 2,269 medications, including 9 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Herbal Cal contains 9 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Herbal Cal label
Go deeper

The Full Monographs Behind Herbal Cal’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Calcium

Interacts with 168 drugs

Calcium is an essential mineral your body needs for strong bones, nerve signaling, and muscle function, and supplements can help fill gaps when diet falls short. Most people do best getting...

Read the full Calcium monograph → Herb & supplement monograph

Slippery Elm

Interacts with 2,022 drugs

Slippery elm is a traditional herbal remedy made from the inner bark of a North American elm tree, used mainly to soothe sore throats and irritated digestive tracts. Its mucilage can coat an...

Read the full Slippery Elm monograph → Herb & supplement monograph

Marshmallow

Interacts with 2,040 drugs

Marshmallow root is a traditional herb rich in soothing, gel-like fibers called mucilage, which is why it has long been used for coughs, sore throats, and stomach irritation. Evidence for th...

Read the full Marshmallow monograph → Herb & supplement monograph

Horsetail

Interacts with 188 drugs

Horsetail is a traditional herb most often used as a mild diuretic and for hair, nail, and bone support, but high-quality human evidence is limited. It can cause thiamine (vitamin B1) loss w...

Read the full Horsetail monograph → Herb & supplement monograph

Valerian

Interacts with 902 drugs

Valerian is an herb whose root is widely used as a natural sleep aid and for calming nerves. The evidence is mixed and often weak, so it may help some people sleep but does not work reliably...

Read the full Valerian monograph → Herb & supplement monograph

Alfalfa

Interacts with 583 drugs

Alfalfa is a nutrient-rich legume that people use for high cholesterol, menopause symptoms, and general wellness, but solid human evidence for most of these uses is limited. It is best avoid...

Read the full Alfalfa monograph → Herb & supplement monograph

Comfrey

Interacts with 438 drugs

Comfrey is a traditional herb used mainly on the skin for bruises, sprains, and joint pain, and some topical products show modest benefit for these uses. However, comfrey contains compounds...

Read the full Comfrey monograph → Herb & supplement monograph

Oats

Interacts with 86 drugs

Oats are a well-studied whole grain whose soluble fiber (beta-glucan) can help lower cholesterol and support heart health when eaten regularly. As a food, oats are safe for most people, and...

Read the full Oats monograph → Herb & supplement monograph

Sea Moss

Interacts with 22 drugs

Sea moss is a type of red seaweed that is naturally rich in iodine and several minerals, and it is popular as a 'whole-food' supplement. Strong human evidence for most of its health claims i...

Read the full Sea Moss monograph →
Sources

Sources & How We Checked

Herbal Cal's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 182 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Calcium 62 references
  1. Shils M, Olson A, Shike M. Modern Nutrition in Health and Disease. 8th ed. Philadelphia, PA: Lea and Febiger, 1994.
  2. Hernandez-Avila M, Gonzalez-Cossio T, Hernandez-Avila JE, et al. Dietary calcium supplements to lower blood lead levels in lactating women: a randomized placebo-controlled trial. Epidemiology 2003;14:206-12.. PubMed
  3. Thys-Jacobs S, Ceccarelli S, Bierman A, et al. Calcium supplementation in premenstrual syndrome: a randomized crossover trial. J Gen Intern Med 1989;4:183-9. PubMed
  4. Maton PN, Burton ME. Antacids revisited: a review of their clinical pharmacology and recommended therapeutic use. Drugs 1999;57:855-70.
  5. Clemens JD, Feinstein AR. Calcium carbonate and constipation: a historical review of medical mythopoeia. Gastroenterology 1977;72:957-61. DOI
  6. Saunders D, Sillery J, Chapman R. Effect of calcium carbonate and aluminum hydroxide on human intestinal function. Dig Dis Sci 1988;33:409-13. PubMed
  7. Friedman PA, Bushinsky DA. Diuretic effects on calcium metabolism. Semin Nephrol 1999;19:551-6.
  8. Koo WK, Walters JC, Esterlitz J, et al. Maternal calcium supplementation and fetal bone mineralization. Obstet Gynecol 1999;94:577-82. DOI
  9. Raman L, Rajalakshmi K, Krishnamachari KAVR, et al. Effect of calcium supplementation to undernourished mothers during pregnancy on the bone density of the neonates. Am J Clin Nutr 1978; 31:466-9. DOI
  10. Murry JJ, Healy MD. Drug-mineral interactions: a new responsibility for the hospital dietician. J Am Diet Assoc 1991;91:66-73.
  11. Chan JM, Giovannucci E, Andersson SO, et al. Dairy products, calcium, phosphorous, vitamin D, and risk of prostate cancer. Cancer Causes Control 1998;9:559-66.
  12. Butner LE, Fulco PP, Feldman G, et al. Calcium carbonate-induced hypothyroidism. Ann Intern Med 2000:132:595. PubMed
  13. Schneyer CR. Calcium carbonate and reduction of levothyroxine efficacy. JAMA 1998;279:750. PubMed
  14. Moser LR, Smythe MA, Tisdale JE. The use of calcium salts in the prevention and management of verapamil-induced hypotension. Ann Pharmacother 2000;34:622-9. PubMed
  15. Singh N, Singh PN, Hershman JM. Effect of calcium carbonate on the absorption of levothyroxine. JAMA 2000;283:2822-5. PubMed
  16. Kahela P, Anttila M, Tikkanen R, Sundquist H. Effect of food, food constituents and fluid volume on the bioavailability of sotalol. Acta Pharmacol Toxicol (Copenh) 1979;44:7-12.. PubMed
  17. Pletz MW, Petzold P, Allen A, et al. Effect of calcium carbonate on bioavailability of orally administered gemifloxacin. Antimicrob Agents Chemother 2003;47:2158-60.. PubMed
  18. Bar-Or D, Yoel G. Calcium and calciferol antagonize effect of verapamil in atrial fibrillation. Br Med J 1981;282:1585-6.
  19. Decktor DL, Robinson M, Maton PN, et al. Effects of aluminum/magnesium hydroxide and calcium carbonate on esophageal and gastric pH in subjects with heartburn. Am J Ther 1995;2:546-52. PubMed
  20. Simoneau G. Absence of rebound effect with calcium carbonate. Eur J Drug Metab Pharmacokinet 1996;21:351-7. PubMed
  21. Peters ML, Leonard M, Licata AA. Role of alendronate and risedronate in preventing and treating osteoporosis. Cleve Clin J Med 2001;68:945-51. PubMed
  22. Bourke JF, Mumford R, Whittaker P, et al. The effects of topical calcipotriol on systemic calcium homeostasis in patients with chronic plaque psoriasis. J Am Acad Dermatol 1997;37:929-34.
  23. Gueguen L, Pointillart A. The bioavailability of dietary calcium. J Am Coll Nutr 2000;19:119s-136s. PubMed
  24. Vella A, Gerber TC, Hayes DL, Reeder GS. Digoxin, hypercalcaemia, and cardiac conduction. Postgrad Med J 1999;75:554-6. PubMed
  25. Bania TC, Blaufeux B, Hughes S, et al. Calcium and digoxin vs. calcium alone for severe verapamil toxicity. Acad Emerg Med 2000;7:1089-96. PubMed
  26. Tseng M, Breslow RA, Graubard BI, Ziegler RG. Dairy, calcium, and vitamin D intakes and prostate cancer risk in the National Health and Nutrition Examination Epidemiologic Follow-up Study cohort. Am J Clin Nutr 2005;81:1147-54. PubMed
  27. Weingarten MA, Zalmanovici A, Yaphe J. Dietary calcium supplementation for preventing colorectal cancer and adenomatous polyps. Cochrane Database Syst Rev 2004;(1):CD003548. PubMed
  28. Tavani A, Bertuccio P, Bosetti C, et al. Dietary intake of calcium, vitamin D, phosphorus and the risk of prostate cancer. Eur Urol 2005;48:27-33. PubMed
  29. Giovannucci E, Liu Y, Stampfer MJ, Willett WC. A prospective study of calcium intake and incident and fatal prostate cancer. Cancer Epidemiol Biomarkers Prev 2006;15:203-10. PubMed
  30. Rocephin (ceftriaxone) and calcium interaction. Pharmacist's Letter / Prescriber's Letter 2007;23(10):231005.
  31. Bolland MJ, Barber PA, Doughty RN, et al. Vascular events in healthy older women receiving calcium supplementation: randomised control trial. BMJ 2008;336:262-6.
  32. Bolland MJ, Avenell A, Baron JA, et al. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ 2010;341:c3691. PubMed
  33. Calcium supplementation and vascular events. Pharmacist's Letter / Prescriber's Letter 2008;24(3):240306.
  34. Dietary reference intakes for calcium and vitamin D. Institute of Medicine, November 30, 2010. Available at: http://www.iom.edu/~/media/Files/Report%20Files/2010/Dietary-Reference-Intakes-for-Calcium-and-Vitamin-D/Vitamin%20D%20and%20Calcium%202010%20Repo
  35. Coburn JW, Mischel MG, Goodman WG, et al. Calcium citrate markedly enhances aluminum absorption from aluminum hydroxide. Am J Kidney Dis. 1991;17(6):708-11. PubMed
  36. Bradley JS, Wassel RT, Lee L, et al. Intravenous ceftriaxone and calcium in the neonate: assessing the risk for cardiopulmonary adverse events. Pediatrics. 2009;123(4):e609-13. PubMed
  37. Kays MB, Overholser BR, Mueller BA, et al. Effects of sevelamer hydrochloride and calcium acetate on the oral bioavailability of ciprofloxacin. Am J Kidney Dis. 2003;42(6):1253-9. PubMed
  38. Neuhofel, A. L., Wilton, J. H., Victory, J. M., Hejmanowsk, L. G., and Amsden, G. W. Lack of bioequivalence of ciprofloxacin when administered with calcium-fortified orange juice: a new twist on an old interaction. J Clin Pharmacol. 2002;42(4):461-466. DOI
  39. Dickinson, H. O., Nicolson, D. J., Cook, J. V., Campbell, F., Beyer, F. R., Ford, G. A., and Mason, J. Calcium supplementation for the management of primary hypertension in adults. Cochrane.Database.Syst.Rev. 2006;(2):CD004639. PubMed
  40. Jones, B. J. and Twomey, P. J. Requesting patterns for serum calcium concentration in patients on long-term lithium therapy. Int J Clin Pract. 2009;63(1):170-172. PubMed
  41. Levine, M., Nikkanen, H., and Pallin, D. J. The effects of intravenous calcium in patients with digoxin toxicity. J Emerg.Med. 2011;40(1):41-46. PubMed
  42. Castelo-Branco, C., Ciria-Recasens, M., Cancelo-Hidalgo, M. J., Palacios, S., Haya-Palazuelos, J., Carbonell-Abello, J., Blanch-Rubio, J., Martinez-Zapata, M. J., Manasanch, J., and Perez-Edo, L. Efficacy of ossein-hydroxyapatite complex compared with ca
  43. Li K, Kaaks R, Linseisen J, Rohrmann S. Associations of dietary calcium intake and calcium supplementation with myocardial infarction and stroke risk and overall cardiovascular mortality in the Heidelberg cohort of the European Prospective Investigation i
  44. Chung M, Tang AM, Fu Z. Calcium Intake and Cardiovascular Disease Risk: An Updated Systematic Review and Meta-analysis. Ann Intern Med. 2016 Oct 25. PubMed
  45. Nolan CR, Califano JR, Butzin CA. Influence of calcium acetate or calcium citrate on intestinal aluminum absorption. Kidney Int. 1990;38(5):937-41. PubMed
  46. Lewis JR, Radavelli-Bagatini S, Rejnmark L, et al. The effects of calcium supplementation on verified coronary heart disease hospitalization and death in postmenopausal women: a collaborative meta-analysis of randomized controlled trials. J Bone Miner Res PubMed
  47. Jalloh MA, Gregory PJ, Hein D, et al. Dietary supplement interactions with antiretrovirals: a systematic review. Int J STD AIDS. 2017 Jan;28(1):4-15. PubMed
  48. Lappe J, Watson P, Travers-Gustafson D, Recker R, Garland C, Gorham E, Baggerly K, McDonnell SL. Effect of Vitamin D and Calcium Supplementation on Cancer Incidence in Older Women: A Randomized Clinical Trial. JAMA. 2017 Mar 28;317(12):1234-1243. PubMed
  49. Grove ML, Cook D. Calcium and heart attacks. Doesn't apply to most calcium prescriptions. BMJ. 2010;341:c5003. PubMed
  50. Insentress [package insert]. Whitehouse Station, NJ: Merck Sharp & Dohme Corp.; 2014.
  51. Roberts JL, Kiser JJ, Hindman JT, Meditz AL. Virologic failure with a raltegravir-containing antiretroviral regimen and concomitant calcium administration. Pharmacotherapy 2011;31(10):298e-302e. DOI
  52. Vitekta [package insert]. Foster City, CA: Gilead Sciences, Inc.; 2014.
  53. Storan ER, O'Gorman SM, Murphy A, Laing M. Case Report of Calciphylaxis Secondary to Calcium and Vitamin D<sub>3</sub> Supplementation. J Cutan Med Surg. 2017;21(2):162-163. DOI
  54. Jenkins DJA, Spence JD, Giovannucci EL, et al. Supplemental vitamins and minerals for CVD prevention and treatment. J Am Coll Cardiol 2018;71(22):2570-84. PubMed
  55. Borkenhagen JF, Connor EL, Stafstrom CE. Neonatal hypocalcemic seizures due to excessive maternal calcium ingestion. Pediatr Neurol 2013;48(6):469-71. PubMed
  56. WHO recommendations on antenatal care for a positive pregnancy experience. Geneva: World Health Organization; 2016 (http://www.who.int/reproductivehealth/publications/maternal_perinatal_health/ anc-positive-pregnancy-experience/en/).
  57. Aune D, Navarro Rosenblatt DA, Chan DS, et al. Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies. Am J Clin Nutr. 2015;101(1):87-117. PubMed
  58. Lan T, Park Y, Colditz GA, et al. Adolescent dairy product and calcium intake in relation to later prostate cancer risk and mortality in the NIH-AARP Diet and Health Study. Cancer Causes Control. 2020;31(10):891-904. PubMed
  59. Zhang Y, Li Y, Liu J, et al. Association of Vitamin D or Calcium Supplementation with Cardiovascular Outcomes and Mortality: A Meta-Analysis with Trial Sequential Analysis. J Nutr Health Aging 2021;25(2):263-270. PubMed
  60. Myung SK, Kim HB, Lee YJ, Choi YJ, Oh SW. Calcium Supplements and Risk of Cardiovascular Disease: A Meta-Analysis of Clinical Trials. Nutrients 2021;13(2):368. PubMed
  61. Hetaimish B. Neonatal Calcinosis Cutis After Treatment of Hypocalcemia with Calcium Gluconate: A Report of 2 Cases. Am J Case Rep 2024;25:e943397. PubMed
  62. US Food and Drug Administration (FDA). Biktarvy Prescribing Information. October 2024. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/210251Orig1s020lbl.pdf. Accessed July 16, 2025.

See these in context on the Calcium monograph →

Slippery Elm 3 references
  1. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  3. Czarnecki D, Nixon R, Bekhor P, and et al. Delayed prolonged contact urticaria from the elm tree. Contact Dermatitis 1993;28:196-197. PubMed

See these in context on the Slippery Elm monograph →

Marshmallow 5 references
  1. Monographs on the medicinal uses of plant drugs. Exeter, UK: European Scientific Co-op Phytother, 1997.
  2. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  3. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  4. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  5. Hage-Sleiman R, Mroueh M, Daher CF. Pharmacological evaluation of aqueous extract of Althaea officinalis flower grown in Lebanon. Pharm Biol 2011;49(3):327-33.

See these in context on the Marshmallow monograph →

Horsetail 14 references
  1. Sudan BJ. Seborrhoeic dermatitis induced by nicotine of horsetails (Equisetum arvense L.). Contact Dermatitis 1985;13:201-2.
  2. Perez Gutierrez RM, Laguna GY, Walkowski A. Diuretic activity of Mexican equisetum. J Ethnopharmacol 1985;14:269-72. PubMed
  3. Lemus I, Garcia R, Erazo S, et al. Diuretic activity of an Equisetum bogotense tea (Platero herb): evaluation in healthy volunteers. J Ethnopharmacol 1996;54:55-8. PubMed
  4. Revilla MC, Andrade-Cetto A, Islas S, Wiedenfeld H. Hypoglycemic effect of Equisetum myriochaetum aerial parts on type 2 diabetic patients. J Ethnopharmacol 2002;81:117-20. PubMed
  5. Tiktinskii, O. L. and Bablumian, I. A. [Therapeutic action of Java tea and field horsetail in uric acid diathesis]. Urol.Nefrol.(Mosk) 1983;3(1):47-50.
  6. Henderson JA, Evans EV, and McIntosh RA. The antithiamine action of Equisetum. J Amer Vet Med Assoc 1952;120:375-378.
  7. Carneiro DM, Freire RC, Honório TC, Zoghaib I, Cardoso FF, Tresvenzol LM, de Paula JR, Sousa AL, Jardim PC, da Cunha LC. Randomized, Double-Blind Clinical Trial to Assess the Acute Diuretic Effect of Equisetum arvense (Field Horsetail) in Healthy Voluntee
  8. Klnçalp S, Ekiz F, Basar Ö, Coban S, Yüksel O. Equisetum arvense (Field Horsetail)-induced liver injury. Eur J Gastroenterol Hepatol. 2012 Feb;24(2):213-4. PubMed
  9. Ortega García JA, Angulo MG, Sobrino-Najul EJ, Soldin OP, Mira AP, Martínez-Salcedo E, Claudio L. Prenatal exposure of a girl with autism spectrum disorder to 'horsetail' (Equisetum arvense) herbal remedy and alcohol: a case report. J Med Case Rep. 2011 M PubMed
  10. Cordova E, Morganti L, Rodriguez C. Possible Drug-Herb Interaction between Herbal Supplement Containing Horsetail (Equisetum arvense) and Antiretroviral Drugs. J Int Assoc Provid AIDS Care. 2017;16(1):11-13.
  11. García Gavilán MD, Moreno García AM, Rosales Zabal JM, Navarro Jarabo JM, Sánchez Cantos A. Case of drug-induced acute pancreatitis produced by horsetail infusions. Rev Esp Enferm Dig. 2017 Apr;109(4):301-304. PubMed
  12. Vieira GT, de Oliveira TT, Carneiro MAA, et al. Antidiabetic effect of Equisetum giganteum L. extract on alloxan-diabetic rabbit. J Ethnopharmacol. 2020;260:112898. PubMed
  13. Health Canada. Organism-Equisetum arvense. Available at: http://webprod.hc-sc.gc.ca/nhpid-bdipsn/ingredReq.do?id=6117&lang=eng. Accessed 21-July 2021.
  14. Bates D, Duong TB, Kheyson S, Moore K. Hyponatremia Secondary to Decreased Oral Intake and SIADH and Possibly Exacerbated by Horsetail (Equisetum arvense). Can J Hosp Pharm 2021;74(4):386-389. PubMed

See these in context on the Horsetail monograph →

Valerian 37 references
  1. Willey LB, Mady SP, Cobaugh DJ, Wax PM. Valerian overdose: a case report. Vet Hum Toxicol 1995;37:364-5.
  2. Kuhlmann J, Berger W, Podzuweit H, Schmidt U. The influence of valerian treatment on "reaction time, alertness and concentration" in volunteers. Pharmacopsychiatry 1999;32:235-41. PubMed
  3. Klepser TB, Klepser ME. Unsafe and potentially safe herbal therapies. Am J Health Syst Pharm 1999;56:125-38. PubMed
  4. Houghton PJ. The scientific basis for the reputed activity of Valerian. J Pharm Pharmacol 1999;51:505-12. PubMed
  5. Garges HP, Varia I, Doraiswamy PM. Cardiac complications and delirium associated with Valerian root withdrawal. [Letter to the Editor]. JAMA 1998;280:1566-7. PubMed
  6. Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
  7. MacGregor FB, Abernethy VE, Dahabra S, et al. Hepatotoxicity of herbal remedies. BMJ 1989;299:1156-7. PubMed
  8. Leathwood PD, Chauffard F. Aqueous extract of valerian reduces latency to fall asleep in man. Planta Med 1985;2:144-8. PubMed
  9. Hadley S, Petry JJ. Valerian. Am Fam Physician 2003;67:1755-8..
  10. Glass JR, Sproule BA, Herrmann N, et al. Acute pharmacological effects of temazepam, diphenhydramine, and valerian in healthy elderly subjects. J Clin Psychopharmacol 2003;23:260-8. PubMed
  11. Lefebvre T, Foster BC, Drouin CE, et al. In vitro activity of commercial valerian root extracts against human cytochrome P450 3A4. J Pharm Pharmaceut Sci 2004;7:265-73.
  12. Yuan CS, Mehendale S, Xiao Y, et al. The gamma-aminobutyric acidergic effects of valerian and valerenic acid on rat brainstem neuronal activity. Anesth Analg 2004;98:353-8. PubMed
  13. Donovan JL, DeVane CL, Chavin KD, et al. Multiple night-time doses of valerian (Valeriana officinalis) had minimal effects on CYP3A4 activity and no effect on CYP2D6 activity in healthy volunteers. Drug Metab Dispos 2004;32:1333-6. PubMed
  14. Gurley BJ, Gardner SF, Hubbard MA, et al. In vivo effects of goldenseal, kava kava, black cohosh, and valerian on human cytochrome P450 1A2, 2D6, 2E1, and 3A4/5 phenotypes. Clin Pharmacol Ther 2005;77:415-26. PubMed
  15. Gutierrez S, Ang-Lee MK, Walker DJ, Zacny JP. Assessing subjective and psychomotor effects of the herbal medication valerian in healthy volunteers. Pharmacol Biochem Behav 2004;78:57-64. PubMed
  16. Jacobs BP, Bent S, Tice JA, et al. An internet-based randomized, placebo-controlled trial of kava and valerian for anxiety and insomnia. Medicine (Baltimore) 2005;84:197-207. PubMed
  17. National Toxicology Program, US Department of Health and Human Services. Chemical Information Review Document for Valerian (Valeriana officinalis L.) [CAS No. 8057-49-6] and Oils [CAS No. 8008-88-6]. Supporting Nomination for Toxicological Evaluation by t
  18. Fernández-San-Martín MI, Masa-Font R, Palacios-Soler L, et al. Effectiveness of Valerian on insomnia: a meta-analysis of randomized placebo-controlled trials. Sleep Med. 2010 Jun;11:505-11. PubMed
  19. Coxeter PD, Schluter PJ, Eastwood HL, et al. Valerian does not appear to reduce symptoms for patients with chronic insomnia in general practice using a series of randomised n-of-1 trials. Complement Ther Med. 2003 Dec;11:215-22. PubMed
  20. Diaper A, Hindmarch I. A double-blind, placebo-controlled investigation of the effects of two doses of a valerian preparation on the sleep, cognitive and psychomotor function of sleep-disturbed older adults. Phytother Res. 2004 Oct;18:831-6. PubMed
  21. Cuellar NG, Ratcliffe SJ. Does valerian improve sleepiness and symptom severity in people with restless legs syndrome? Altern Ther Health Med 2009;15:22-8.
  22. Chen D, Klesmer J, Giovanniello A, et al. Mental status changes in an alcohol abuser taking valerian and gingko biloba. Am J Addict. 2002 Winter;11:75-7. PubMed
  23. Albrecht M, Berger W, Laux P, Schmidt U, et al. Psychopharmaka und Verkehrssicherheit. Der Einfluß von Euvegal&reg; - Dragees forte auf die Fahrtüchtigkeit und Kombinationswirkungen mit Alkohol Z Allg Med 1995;71:1215-25.
  24. Carrasco MC, Vallejo JR, Pardo-de-Santayana M, et al. Interactions of Valeriana officinalis L. and Passiflora incarnata L. in a patient treated with lorazepam. Phytother Res. 2009 Dec;23:1795-6.
  25. Hellum BH, Nilsen OG. The in vitro inhibitory potential of trade herbal products on human CYP2D6-mediated metabolism and the influence of ethanol. Basic Clin Pharmacol Toxicol. 2007 Nov;101:350-8.
  26. Hellum BH, Hu Z, Nilsen OG. The induction of CYP1A2, CYP2D6 and CYP3A4 by six trade herbal products in cultured primary human hepatocytes. Basic Clin Pharmacol Toxicol. 2007 Jan;100:23-30. PubMed
  27. Alkharfy, K. M. and Frye, R. F. Effect of valerian, valerian/hops extracts, and valerenic acid on glucuronidation in vitro. Xenobiotica 2007;37(2):113-123.
  28. Vassiliadis, T., Anagnostis, P., Patsiaoura, K., Giouleme, O., Katsinelos, P., Mpoumponaris, A., and Eugenidis, N. Valeriana hepatotoxicity. Sleep Med 2009;10(8):935. PubMed
  29. Muller, Z., Sarkany, A., Altorjay, A., Szilagyi, A., Tura, T., and Ozsvar, Z. [Liver failure a la Eastern Europe]. Orv.Hetil. 3-22-2009;150(12):555-557. PubMed
  30. National Toxicology Program, US Department of Health and Human Services. Chemical Information Review Document for Valerian (Valeriana officinalis L.) [CAS No. 8057-49-6] and Oils [CAS No. 8008-88-6]. 2009;
  31. Wells SR. International intravenous administration of a crude valerian root extract. NACCT 1995;33:542.
  32. Aydinoglu U, Özcan H, Yücel A, Yücel N, Mutlu M. Valerian induced hypomania: a case report. Bull Clin Psychopharma 2012;22(Suppl. 1):S63.
  33. Mirabi P, Mojab F. The effects of valerian root on hot flashes in menopausal women. Iran J Pharm Res 2013;12(1):217-22.
  34. Thomas K, Canedo J, Perry PJ, et al. Effects of valerian on subjective sedation, field sobriety testing and driving simulator performance. Accid Anal Prev. 2016 Jul;92:240-4. PubMed
  35. Kia YH, Alexander S, Dowling D, Standish R. A case of steroid-responsive valerian-associated hepatitis. Intern Med J. 2016 Jan;46(1):118-9. PubMed
  36. Burke H, Jiang S, Chatham P, Stern TA. Delirium After Withdrawal From Valerian Root: A Case Report. Psychosomatics. 2020;61(6):787-790. PubMed
  37. Hajizadeh I, Jamshidi M, Kazemi M, Kargar H, Sadeghi T. Comparison the effect of valerian and gabapentin on RLS and sleep quality in hemodialysis patients: A randomized clinical trial. Ther Apher Dial 2023.

See these in context on the Valerian monograph →

Alfalfa 32 references
  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  3. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  4. Kurzer MS, Xu X. Dietary phytoestrogens. Annu Rev Nutr 1997;17:353-81. PubMed
  5. Farber JM, Carter AO, Varughese PV, et al. Listeriosis traced to the consumption of alfalfa tablets and soft cheese [Letter to the Editor]. N Engl J Med 1990;322:338. PubMed
  6. Molgaard J, von Schenck H, Olsson AG. Alfalfa seeds lower low density lipoprotein cholesterol and apolipoprotein B concentrations in patients with type II hyperlipoproteinemia. Atherosclerosis 1987;65:173-9. PubMed
  7. Light TD, Light JA. Acute renal transplant rejection possibly related to herbal medications. Am J Transplant 2003;3:1608-9. PubMed
  8. Prete PE. The mechanism of action of L-canavanine in inducing autoimmune phenomena. Arthritis Rheum 1985;28:1198-200. PubMed
  9. Alcocer-Varela J, Iglesias A, Llorente L, Alarcon-Segovia D. Effects of L-canavanine on T cells may explain the induction of systemic lupus erythematosus by alfalfa. Arthritis Rheum 1985;28:52-7. PubMed
  10. Roberts JL, Hayashi JA. Exacerbation of SLE associated with alfalfa ingestion. N Engl J Med 1983;308:1361. DOI
  11. Feingold, R. M. Should we fear "health foods"? Arch Intern Med 7-12-1999;159(13):1502. PubMed
  12. Taormina, P. J., Beuchat, L. R., and Slutsker, L. Infections associated with eating seed sprouts: an international concern. Emerg.Infect.Dis 1999;5(5):626-634. PubMed
  13. Backer, H. D., Mohle-Boetani, J. C., Werner, S. B., Abbott, S. L., Farrar, J., and Vugia, D. J. High incidence of extra-intestinal infections in a Salmonella Havana outbreak associated with alfalfa sprouts. Public Health Rep. 2000;115(4):339-345. PubMed
  14. Mohle-Boetani J, Werner B, Polumbo M, and et al. From the Centers for Disease Control and Prevention. Alfalfa sprouts-- Arizona, California, Colorado, and New Mexico, February-April, 2001. JAMA 2-6-2002;287(5):581-582.
  15. Howard, M. B. and Hutcheson, S. W. Growth dynamics of Salmonella enterica strains on alfalfa sprouts and in waste seed irrigation water. Appl.Environ.Microbiol. 2003;69(1):548-553.
  16. Winthrop, K. L., Palumbo, M. S., Farrar, J. A., Mohle-Boetani, J. C., Abbott, S., Beatty, M. E., Inami, G., and Werner, S. B. Alfalfa sprouts and Salmonella Kottbus infection: a multistate outbreak following inadequate seed disinfection with heat and chl
  17. Strapp, C. M., Shearer, A. E., and Joerger, R. D. Survey of retail alfalfa sprouts and mushrooms for the presence of Escherichia coil O157:H7, Salmonella, and Listeria with BAX, and evaluation of this polymerase chain reaction-based system with experimen
  18. Akaogi, J., Barker, T., Kuroda, Y., Nacionales, D. C., Yamasaki, Y., Stevens, B. R., Reeves, W. H., and Satoh, M. Role of non-protein amino acid L-canavanine in autoimmunity. Autoimmun.Rev 2006;5(6):429-435. PubMed
  19. Burden and causes of foodborne disease in Australia: Annual report of the OzFoodNet network, 2005. Commun.Dis Intell. 2006;30(3):278-300.
  20. Shemesh, M., Lindner, H. R., and Ayalon, N. Affinity of rabbit uterine oestradiol receptor for phyto-oestrogens and its use in a competitive protein-binding radioassay for plasma coumestrol. J Reprod.Fertil. 1972;29(1):1-9. PubMed
  21. Elakovich, S. D. and Hampton, J. M. Analysis of coumestrol, a phytoestrogen, in alfalfa tablets sold for human consumption. J Agric.Food Chem. 1984;32(1):173-175. PubMed
  22. Malinow, M. R., Bardana, E. J., Jr., Pirofsky, B., Craig, S., and McLaughlin, P. Systemic lupus erythematosus-like syndrome in monkeys fed alfalfa sprouts: role of a nonprotein amino acid. Science 4-23-1982;216(4544):415-417. PubMed
  23. Malinow, M. R., McLaughlin, P., and Stafford, C. Alfalfa seeds: effects on cholesterol metabolism. Experientia 5-15-1980;36(5):562-564. PubMed
  24. Farnsworth, N. R. Alfalfa pills and autoimmune diseases. Am J Clin Nutr. 1995;62(5):1026-1028. DOI
  25. Herbert, V. and Kasdan, T. S. Alfalfa, vitamin E, and autoimmune disorders. Am J Clin Nutr 1994;60(4):639-640.
  26. Mahon, B. E., Ponka, A., Hall, W. N., Komatsu, K., Dietrich, S. E., Siitonen, A., Cage, G., Hayes, P. S., Lambert-Fair, M. A., Bean, N. H., Griffin, P. M., and Slutsker, L. An international outbreak of Salmonella infections caused by alfalfa sprouts grow
  27. Gray, A. M. and Flatt, P. R. Pancreatic and extra-pancreatic effects of the traditional anti- diabetic plant, Medicago sativa (lucerne). Br J Nutr. 1997;78(2):325-334.
  28. Van Beneden, C. A., Keene, W. E., Strang, R. A., Werker, D. H., King, A. S., Mahon, B., Hedberg, K., Bell, A., Kelly, M. T., Balan, V. K., Mac Kenzie, W. R., and Fleming, D. Multinational outbreak of Salmonella enterica serotype Newport infections due to
  29. Rubenstein AH, Levin NW, and Elliott GA. Manganese-induced hypoglycemia. Lancet 1962;1348-1351.
  30. Kaufman W. Alfalfa seed dermatitis. JAMA 1954;155(12):1058-1059. PubMed
  31. Ponka A, Andersson Y, Siitonen A, and et al. Salmonella in alfalfa sprouts. Lancet 1995;345:462-463. PubMed
  32. Puschner B, Chen X, Read D, Affolter VK. Alfalfa hay induced primary photosensitization in horses. Vet J. 2016 May;211:32-8. PubMed

See these in context on the Alfalfa monograph →

Comfrey 13 references
  1. Stewart MJ, Steenkamp V. Pyrrolizidine poisoning: a neglected area in human toxicology. Ther Drug Monit 2001;23:698-708. PubMed
  2. Food and Drug Administration. FDA Advises Dietary Supplement Manufacturers to Remove Comfrey Products From the Market. July 6, 2001. Available at: http://www.cfsan.fda.gov/~dms/dspltr06.html.
  3. Stickel F, Seitz HK. The efficacy and safety of comfrey. Public Health Nutr 2000;3:501-8. PubMed
  4. Chojkier M. Hepatic sinusoidal-obstruction syndrome: toxicity of pyrrolizidine alkaloids. J Hepatol 2003;39:437-46. PubMed
  5. Wang YP, Yan J, Fu PP, Chou MW. Human liver microsomal reduction of pyrrolizidine alkaloid N-oxides to form the corresponding carcinogenic parent alkaloid. Toxicol Lett 2005;155:411-20. PubMed
  6. Predel, H. G., Giannetti, B., Koll, R., Bulitta, M., and Staiger, C. Efficacy of a comfrey root extract ointment in comparison to a diclofenac gel in the treatment of ankle distortions: results of an observer-blind, randomized, multicenter study. Phytome
  7. Gyorik, S. and Stricker, H. Severe pulmonary hypertension possibly due to pyrrolizidine alkaloids in polyphytotherapy. Swiss.Med.Wkly. 4-4-2009;139(13-14):210-211.
  8. Giannetti, B. M., Staiger, C., Bulitta, M., and Predel, H. G. Efficacy and safety of comfrey root extract ointment in the treatment of acute upper or lower back pain: results of a double-blind, randomised, placebo controlled, multicentre trial. Br.J Spor PubMed
  9. Tanret, I. and Duh, D. [Pharmaceutical sheet. Symphytum officinale L., dermal use (Flexagile cream)]. J Pharm.Belg. 2012;(1):41-42.
  10. Laslett, L. L., Quinn, S. J., Darian-Smith, E., Kwok, M., Fedorova, T., Korner, H., Steels, E., March, L., and Jones, G. Treatment with 4Jointz reduces knee pain over 12 weeks of treatment in patients with clinical knee osteoarthritis: a randomised contr
  11. Frost R, Macpherson H, O'meara S. A critical scoping review of external uses of comfrey (Symphytum spp.). Complement Ther Med. 2013;21(6):724-45. PubMed
  12. Pabst H, Schaefer A, Staiger C, Junker-samek M, Predel HG. Combination of comfrey root extract plus methyl nicotinate in patients with conditions of acute upper or low back pain: a multicentre randomised controlled trial. Phytother Res. 2013;27(6):811-7. PubMed
  13. Smith DB, Jacobson BH. Effect of a blend of comfrey root extract (Symphytum officinale L.) and tannic acid creams in the treatment of osteoarthritis of the knee: randomized, placebo-controlled, double-blind, multiclinical trials. J Chiropr Med. 2011;10(3) PubMed

See these in context on the Comfrey monograph →

Oats 13 references
  1. Cooper SG, Tracey EJ. Small-bowel obstruction caused by oat-bran bezoar. N Engl J Med 1989;320:1148-9. DOI
  2. Pick ME, Hawrysh ZJ, Gee MI, et al. Oat bran concentrate bread products improve long-term control of diabetes: a pilot study. J Am Diet Assoc 1996;96:1254-61. PubMed
  3. Braaten JT, Scott FW, Wood PJ, et al. High beta-glucan oat bran and oat gum reduce postprandial blood glucose and insulin in subjects with and without type 2 diabetes. Diabet Med 1994;11:312-8.
  4. Rosario PG, Gerst PH, Prakash K, Albu E. Dentureless distention: oat bran bezoars cause obstruction. J Am Geriatr Soc 1990;38:608. PubMed
  5. Food and Drug Administration. Food labeling: health claims: oats and coronary heart disease. Fed Regist 1996;61:296-313.
  6. Foulke J. FDA Allows Whole Oat Foods To Make Health Claim on Reducing the Risk of Heart Disease. FDA Talk Paper. 1997. Available at: http://www.fda.gov/bbs/topics/ANSWERS/ANS00782.html.
  7. Chandalia M, Garg A, Lutjohann D, et al. Beneficial effects of high dietary fiber intake in patients with type 2 diabetes mellitus. N Engl J Med 2000;342:1392-8. PubMed
  8. Lembo A, Camilleri M. Chronic constipation. N Engl J Med 2003;349:1360-8. . PubMed
  9. De Paz Arranz S, Perez Montero A, Remon LZ, Molero MI. Allergic contact urticaria to oatmeal. Allergy 2002;57:1215. . PubMed
  10. Delgado G, Kleber ME, Kr&auml;mer BK, et al. Dietary intervention with oatmeal in patients with uncontrolled type 2 diabetes mellitus - A crossover study. Exp Clin Endocrinol Diabetes. 2019;127(9):623-629. PubMed
  11. Sobhan M, Hojati M, Vafaie SY, Ahmadimoghaddam D, Mohammadi Y, Mehrpooya M. The efficacy of colloidal oatmeal cream 1% as add-on therapy in the management of chronic irritant hand eczema: A double-blind study. Clin Cosmet Investig Dermatol. 2020;13:241-25
  12. Hou Q, Li Y, Li L, Cheng G, Sun X, Li S, Tian H. The metabolic effects of oats intake in patients with type 2 diabetes: A systematic review and meta-analysis. Nutrients. 2015;7(12):10369-87. PubMed
  13. González-Afonso M, Cañas JA, Sastre B, et al. A Case of Anaphylaxis After Ingestion of Oats: Research Into New Allergens. J Investig Allergol Clin Immunol 2022;32(6):506-508. PubMed

See these in context on the Oats monograph →

Sea Moss 3 references
  1. Darias-Rosales J, Rubio C, Gutiérrez ÁJ, Paz S, Hardisson A. Risk assessment of iodine intake from the consumption of red seaweeds (Palmaria palmata and Chondrus crispus). Environ Sci Pollut Res Int 2020;27(36):45737-45741. PubMed
  2. U.S. Department of Agriculture (USDA). Agricultural Research Service. FoodData Central. Seaweed, irishmoss, raw. April 2019. Available at: https://fdc.nal.usda.gov/fdc-app.html#/food-details/168456/nutrients. Accessed Aug. 30, 2022.
  3. Palmieri B, Vadalà M, Laurino C. Clinical effects of overwintered-stressed Chondrus Crispus and non-overwintered-stressed Chondrus crispus dietary supplementations. Asian J Med Sci. 2018; 9(6): 7-13. DOI

See these in context on the Sea Moss monograph →

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DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

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