Interactions on record — worth a quick check against your medications. Check your meds →
Dietary supplement

Back Formula Ingredients & Drug Interactions

by Indiana Botanic Gardens

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

First and foremost: checking Back Formula 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: Moderate

Back Formula is a dietary supplement by Indiana Botanic Gardens with 3 active ingredients. Its ingredients are commonly taken for bone health and osteoporosis, correcting vitamin d deficiency, immune system support.Based on those ingredients, 935 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Devil's Claw extract, Vitamin D3, Willow bark extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Back Formula by Indiana Botanic Gardens

Ask about any prescription or over-the-counter medication and we check it for interactions with Back Formula by Indiana Botanic Gardens — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Back Formula by Indiana Botanic Gardens

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 12, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 3 of its 3 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Back Formula contains 3 active ingredients. Vitamin D3 is a fat-soluble vitamin used to treat conditions like rickets, osteomalacia (soft bones), and low blood calcium; it's effective for those uses at therapeutic doses.

Willow bark extract is a plant-based ingredient with salicin (a compound related to aspirin) that may help with back pain. Devil's claw extract is another botanical ingredient, also studied for back pain and osteoarthritis support.

The product also contains several inactive ingredients—rice flour, gelatin, maltodextrin, magnesium stearate, sucrose, corn starch, vitamin E (DL-alpha-tocopherol), and stearic acid—which serve as fillers, binders, and capsule material.

Does it work?

Moderate evidence
Evidence for Intended Use · database check
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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: Back pain and joint support.
  • We looked for evidence on: Back pain, Joint pain, Osteoarthritis, Lower back pain.
  • The strongest evidence on file: Willow Bark is rated "Possibly Effective" for Back pain (Natural Medicines).
  • Also on file: Devil's Claw is rated "Possibly Effective" for Back pain, Osteoarthritis.
  • Also on file: Vitamin D is rated "Insufficient Reliable Evidence To Rate" for Back pain, Osteoarthritis.

Vitamin D3 is effective for rickets, osteomalacia, renal bone disease, and hypoparathyroidism—conditions involving bone health and calcium regulation—at appropriate medical doses. Willow bark extract and devil's claw extract are both rated possibly effective for back pain, meaning the evidence suggests they may help but isn't definitive.

For other uses listed on the label, like headache or common cold (willow bark), the evidence we hold is insufficient to rate them.

The evidence, ingredient by ingredient Vitamin D Willow Bark Devil's Claw

How safe is it?

Well-documented data
Safety Information · database check
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 3 of the 3 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 3 of 3.
  • General safety write-ups exist for 3 of 3.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Vitamin D3 is generally well tolerated at recommended doses, though very high doses over time can cause vitamin D toxicity with symptoms of high blood calcium (hypercalcemia). It's likely safe in pregnancy and lactation at recommended amounts, but use only under your doctor's guidance.

Willow bark is generally tolerated short-term by healthy adults but acts like aspirin and isn't safe for everyone; the data advises against it during pregnancy due to aspirin-like risks, especially later in pregnancy, and while breastfeeding due to insufficient safety data. Devil's claw is generally well tolerated for short-term use but can cause digestive upset (diarrhea, heartburn, nausea); the data advises against it in pregnancy because it may affect the uterus and while breastfeeding due to insufficient safety information.

Serious adverse effects (like gastrointestinal bleeding) are rare with all three ingredients.

Side effects, ingredient by ingredient Vitamin D Willow Bark Devil's Claw

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 3 of the 3 matched ingredients can interact with medications — Vitamin D, Willow Bark, Devil's Claw.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; heart-rhythm medications.
  • For scale: 936 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.

Before taking Back Formula, double-check if you're on blood thinners (anticoagulants) or antiplatelet drugs like warfarin, aspirin, or clopidogrel—willow bark and devil's claw can interfere. If you take heart rhythm medications (verapamil, diltiazem, digoxin), diuretics, statins like atorvastatin, or any drug metabolized by your liver's CYP2C9, CYP2C19, or CYP3A4 enzymes, flag this product with your pharmacist.

Also check if you're on stomach-acid reducers (H2-blockers or PPIs) or any salicylate-containing pain medication. Use the medication checker below to verify your specific drugs.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Back Formula may be worth considering if you have back pain or osteoarthritis and don't take blood thinners, heart medications, or stomach-acid reducers. If you take any prescription drugs—especially for the heart, blood clotting, cholesterol, or digestion—check your medications with the tool on this page first.

Pregnant or breastfeeding? Talk to your pharmacist or doctor before starting; the ingredients have specific cautions for both.

It's a good idea to run this by your pharmacist regardless, given the number of potential interactions.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 3 of 3 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jun 25, 2015.

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 Back Formula, straight from the product label.

Brand Indiana Botanic Gardens
Barcode (UPC) 703308810370
Net contents 30 Capsule(s)
Market status On market
Date entered into DSLD Jun 25, 2015
DSLD ID 46855
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other
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 Back Formula by Indiana Botanic Gardens, 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:
2 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
15
UPC/BARCODE
703308810370
IngredientAmount% DV
Vitamin D3800 IU200%
Willow bark extract250 mg--
Devil's Claw extract960 mg--

Other ingredients: Rice Flour, Gelatin, Maltodextrin, Magnesium Stearate, Sucrose, Corn Starch, DL-Alpha-Tocopherol, Stearic Acid

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 Statements

New and Improved!

FDA Statement of Identity

Dietary Supplement

Seals/Symbols

IBG INDIANA BOTANIC GARDENS(R)

Suggested/Recommended/Usage/Directions

Suggested Use: Take 2 capsules once daily, with meals, as a dietary supplement, or as directed by a physician.

Precautions

Warning: If you are taking any medications or are pregnant or nursing do not use prior to consulting a physician.

For your protection, this container has an outer safety seal. (Do not accept if missing or broken.)

KEEP OUT OF REACH OF CHILDREN

Storage

Store in a dry, cool place.

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

See for yourself

Back Formula by Indiana Botanic Gardens label

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

Back Formula 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 Back Formula by Indiana Botanic Gardens

These are the 3 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Capsule(s) Dosage formCapsule Servings per container15 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.

Vitamin D3

Interacts with
715 drugs
800 IU per serving Form: Cholecalciferol

Vitamin D is a fat-soluble vitamin that helps your body absorb calcium and is important for healthy bones, muscles, and immune function. Many people,...

Vitamin D3 monograph & interactions

Willow bark extract

Interacts with
127 drugs
250 mg per serving

Willow bark is a traditional plant remedy that contains salicin, a compound related to aspirin, and is most often used for pain and inflammation. Some...

Willow bark extract monograph & interactions

Devil's Claw extract

Interacts with
804 drugs
960 mg per serving Form: Harpagosides

Devil's claw is a southern African plant used mainly for arthritis and back pain, and some studies suggest it may help ease these types of discomfort....

Devil's Claw extract monograph & interactions

Other (inactive) ingredients: Rice Flour, Gelatin, Maltodextrin, Magnesium Stearate, Sucrose, Corn Starch, DL-Alpha-Tocopherol, Stearic Acid. These complete the product’s ingredient list but are not active constituents.

Interaction report

Back Formula by Indiana Botanic Gardens Drug Interactions

Want to check YOUR meds against Back Formula?

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
935Drugs
867 Moderate 68 Minor

Ingredients driving the most interactions

Devil's Claw extract 804
Vitamin D3 715
Willow bark extract 127

Individual Drug Interactions

The ingredients in Back Formula interact with 935 drugs. Click any drug to see the details.

3 of the 3 ingredients in Back Formula interact with drugs. Each result below shows which ingredient is responsible. Devil's Claw extract Vitamin D3 Willow bark extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Back Formula 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.

Devil's Claw extract7 drug types · 804 drugs

Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, devil's claw might increase levels of drugs metabolized by CYP2C19.
In vitro research shows that devil's claw might inhibit CYP2C19, although this has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, devil's claw might increase levels of drugs metabolized by CYP2C9.
In vitro research shows that devil's claw might inhibit CYP2C9, although this has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, devil's claw might increase levels of drugs metabolized by CYP3A4.
In vitro research shows that devil's claw might inhibit CYP3A4, although this has not been reported in humans.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, Devil's claw might increase the activity of warfarin.
In one case report, purpura occurred in a patient taking warfarin and devil's claw concurrently. This might indicate over-anticoagulation. It is unclear if this was due to Devil's claw or other contributing factors.

Likelihood Possible Evidence D
H2-Blockers

Theoretically, devil's claw might decrease the effectiveness of H2-blockers.
Devil's claw has been reported to increase stomach acid, which might interfere with the effects of H2-blockers.

Likelihood Possible Evidence D
P-Glycoprotein Substrates

Theoretically, devil's claw might increase levels of P-glycoprotein substrates.
In vitro research shows that devil's claw inhibits P-glycoprotein, which transports many drugs out of cells. This might increase intracellular levels of P-glycoprotein substrates, although it is unclear if this effect would be clinically important.

Likelihood Possible Evidence D
Proton Pump Inhibitors (Ppis)

Theoretically, devil's claw might decrease the effectiveness of PPIs.
Devil's claw has been reported to increase stomach acid, which might interfere with the effects of PPIs.

Likelihood Possible Evidence D
Devil's Claw extract full monograph & interactions

Vitamin D38 drug types · 715 drugs

Aluminum

Vitamin D might increase aluminum absorption and toxicity, but this has only been reported in people with renal failure.
The protein that transports calcium across the intestinal wall can also bind and transport aluminum. This protein is stimulated by vitamin D, which may therefore increase aluminum absorption. This mechanism may contribute to increased aluminum levels and toxicity in people with renal failure, when they take vitamin D and aluminum-containing phosphate binders chronically.

Likelihood Probable Evidence B
Atorvastatin (Lipitor)

Vitamin D might reduce absorption of atorvastatin.
A small, low-quality clinical study shows that taking vitamin D reduces levels of atorvastatin and its active metabolites by up to 55%. However, while atorvastatin levels decreased, total cholesterol, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol levels did not substantially change. Atorvastatin is metabolized in the gut by CYP3A4 enzymes, and researchers theorized that vitamin D might induce CYP3A4, causing reduced levels of atorvastatin. However, this proposed mechanism was not specifically studied.

Likelihood Probable Evidence B
Calcipotriene (Dovonex)

Taking calcipotriene with vitamin D increases 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 vitamin D supplements might increase the risk of hypercalcemia.

Likelihood Probable Evidence D
Digoxin (Lanoxin)

Theoretically, hypercalcemia induced by high-dose vitamin D can increase the risk of arrhythmia from digoxin.
High doses of vitamin D can cause hypercalcemia. Hypercalcemia increases the risk of fatal cardiac arrhythmias with digoxin. Avoid vitamin D doses above the tolerable upper intake level (4000 IU daily for adults) and monitor serum calcium levels in people taking vitamin D and digoxin concurrently.

Likelihood Possible Evidence D
Diltiazem (Cardizem, Others)

Theoretically, hypercalcemia induced by high-dose vitamin D can reduce the therapeutic effects of diltiazem for arrhythmia.
High doses of vitamin D can cause hypercalcemia. Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation. Theoretically this could also occur with diltiazem. Avoid vitamin D doses above the tolerable upper intake level (4000 IU daily for adults) and monitor serum calcium levels in people taking vitamin D and diltiazem concurrently.

Likelihood Probable Evidence B
Thiazide Diuretics

Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Thiazide diuretics decrease urinary calcium excretion, which could lead to hypercalcemia if vitamin D supplements are taken concurrently. This has been reported in people being treated with vitamin D for hypoparathyroidism, and also in elderly people with normal parathyroid function who were taking a thiazide, vitamin D, and calcium-containing antacids daily.

Likelihood Probable Evidence D
Verapamil (Calan, Others)

Hypercalcemia induced by high-dose vitamin D can reduce the therapeutic effects of verapamil for arrhythmia.
Hypercalcemia due to high doses of vitamin D can reduce the effectiveness of verapamil in atrial fibrillation. Avoid vitamin D doses above the tolerable upper intake level (4000 IU daily for adults) and monitor serum calcium levels in people taking vitamin D and verapamil concurrently.

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

Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
There is some concern that vitamin D might induce CYP3A4. In vitro research suggests that vitamin D induces CYP3A4 transcription. Additionally, observational research has found that increased UV light exposure and serum vitamin D levels are associated with decreased serum levels of CYP3A4 substrates such as tacrolimus and sirolimus, while no association between UV light exposure or vitamin D levels and levels of mycophenolic acid, a non-CYP3A4 substrate, was found. A small, low-quality clinical study shows that taking vitamin D reduces levels of the CYP3A4 substrate atorvastatin and its active metabolites by up to 55%; however, the clinical effects of atorvastatin were not reduced. While researchers theorized that vitamin D might induce CYP3A4, this proposed mechanism was not specifically studied.

Likelihood Possible Evidence D
Vitamin D3 full monograph & interactions

Willow bark extract5 drug types · 127 drugs

Acetazolamide

Theoretically, willow bark might result in additive adverse effects associated with acetazolamide.
Willow bark contains salicin, a plant salicylate. Human case reports suggests that a combination of acetazolamide and salicylate increases unbound plasma levels of acetazolamide, as well as adverse effects related to acetazolamide.

Likelihood Possible Evidence D
Anticoagulant/Antiplatelet Drugs

Theoretically, willow bark might increase the risk of bleeding when taken with anticoagulant/antiplatelet drugs.
Willow bark has antiplatelet effects, but less so than aspirin.

Likelihood Probable Evidence D
Aspirin

Theoretically, willow bark might increase the effects and adverse effects of aspirin.
Willow bark contains salicin, a plant salicylate. It might have an additive effect when taken with other salicylate-containing drugs such as aspirin.

Likelihood Probable Evidence D
Choline Magnesium Trisalicylate (Trilisate)

Theoretically, willow bark might increase the effects and adverse effects of choline magnesium trisalicylate.
Willow bark contains salicin, a plant salicylate. It might have an additive effect when taken with other salicylate-containing drugs such as choline magnesium trisalicylate.

Likelihood Probable Evidence D
Salsalate (Disalcid)

Theoretically, willow bark might increase the effects and adverse effects of salsalate.
Willow bark contains salicin, a plant salicylate. It might have an additive effect when taken with other salicylate-containing drugs such as salsalate.

Likelihood Probable Evidence D
Willow bark extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Back Formula, from the product label.

Indiana Botanic Gardens

See all Indiana Botanic Gardens products
Web Address
www.botanicchoice.com
Pharmacist Counseling Corner

Back Formula by Indiana Botanic Gardens: Common Questions

Does Back Formula by Indiana Botanic Gardens interact with any medications?
Yes. Based on its ingredients, Back Formula has a known interaction with 935 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Back Formula contains 3 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.
Does Back Formula actually help with back pain?
Willow bark extract and devil's claw extract—two of the three active ingredients—are both rated possibly effective for back pain, meaning research suggests they may help but the evidence isn't definitive. Vitamin D3 is included for bone health, not pain relief. Results vary from person to person.
Is this safe to take if I'm pregnant?
The three ingredients have different safety ratings in pregnancy. Vitamin D3 is likely safe at recommended doses under your doctor's guidance, but willow bark should be avoided (especially later in pregnancy due to its aspirin-like effects) and devil's claw should also be avoided because its effects on pregnancy haven't been established. Talk with your doctor or pharmacist before starting.
What are the most common side effects?
Willow bark may cause diarrhea, heartburn, nausea, or rash in some people. Devil's claw can cause diarrhea, heartburn, or mild digestive upset, especially at higher doses. Serious side effects like gastrointestinal bleeding are rare. High-dose vitamin D over time can lead to vitamin D toxicity.
Can I take this while breastfeeding?
Vitamin D3 is likely safe at recommended doses while breastfeeding, but willow bark and devil's claw should be avoided due to insufficient safety information. Talk with your doctor or pharmacist before taking this product while nursing.
What exactly is in this capsule?
The three active ingredients are vitamin D3 (for bone health), willow bark extract (containing salicin, like aspirin), and devil's claw extract (from a plant root). The capsule also contains fillers and binders: rice flour, gelatin, maltodextrin, magnesium stearate, sucrose, corn starch, vitamin E, and stearic acid.
Why does this interact with so many medications?
The three ingredients interact with medications in different ways. Vitamin D3 can affect blood calcium and how certain heart and cholesterol drugs work. Willow bark acts like aspirin and thins blood, so it affects blood thinners and bleeding risk. Devil's claw may change how your liver breaks down many common drugs. That's why checking your specific medications is important.

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.

Back Formula label
Go deeper

The Full Monographs Behind Back Formula’s Ingredients

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

Herb & supplement monograph

Vitamin D

Interacts with 715 drugs

Vitamin D is a fat-soluble vitamin that helps your body absorb calcium and is important for healthy bones, muscles, and immune function. Many people, especially those with low sun exposure,...

Read the full Vitamin D monograph → Herb & supplement monograph

Willow Bark

Interacts with 127 drugs

Willow bark is a traditional plant remedy that contains salicin, a compound related to aspirin, and is most often used for pain and inflammation. Some evidence suggests it may modestly help...

Read the full Willow Bark monograph → Herb & supplement monograph

Devil's Claw

Interacts with 804 drugs

Devil's claw is a southern African plant used mainly for arthritis and back pain, and some studies suggest it may help ease these types of discomfort. The evidence is moderate at best, and p...

Read the full Devil's Claw monograph →
Sources

Sources & How We Checked

Back Formula'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 56 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.

Vitamin D 26 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Tatro DS, ed. Drug Interactions Facts. Facts and Comparisons Inc., St. Louis, MO. 1999.
  3. Koutkia P, Chen TC, Holick MF. Vitamin D intoxication associated with an over-the-counter supplement. N Engl J Med 2001;345:66-7. PubMed
  4. Bar-Or D, Yoel G. Calcium and calciferol antagonize effect of verapamil in atrial fibrillation. Br Med J 1981;282:1585-6.
  5. Demontis R, Leflon A, Fournier A, et al. 1 alpha(OH) vitamin D3 increases plasma aluminum in hemodialyzed patients taking AI(OH)3. Clin Nephrol 1986;26:146-9.
  6. Crowe M, Wollner L, Griffiths RA. Hypercalcemia following vitamin D and thiazide therapy in the elderly. Practitioner 1984;228:312-3.
  7. Parfitt AM. Thiazide-induced hypercalcemia in vitamin D-treated hypoparathyroidism. Ann Intern Med 1972;77:557-63. PubMed
  8. Thiazide diuretics and the risk of osteoporosis. Pharmacist's Letter/Prescriber's Letter 2003;19(11):191105.
  9. Moon J. The role of vitamin D in toxic metal absorption. J Am Coll Nutr 1994;13:559-64.
  10. Demontis R, Reissi D, Noel C, et al. Indirect clinical evidence that 1alphaOH vitamin D<SUB>3</SUB> increases the intestinal absorption of aluminum. Clin Nephrol 1989;31:123-7.
  11. Adler AJ, Berlyne GM. Duodenal aluminum absorption in the rat: effect of vitamin D. Am J Physiol 1985;249:G209-13. PubMed
  12. Schwartz JB. Effects of vitamin D supplementation in atorvastatin-treated patients: A new drug interaction with an unexpected consequence. Clin Pharmacol Ther 2009;85:198-203. PubMed
  13. 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
  14. Cox KA, Dunn MA. Aluminum toxicity alters the regulation of calbindin-D28k protein and mRNA expression in chick intestine. J Nutr 2001;131:2007-13. PubMed
  15. Escribano, J., Balaguer, A., Pagone, F., Feliu, A., and Roque, I. Figuls. Pharmacological interventions for preventing complications in idiopathic hypercalciuria. Cochrane.Database.Syst.Rev. 2009;(1):CD004754. PubMed
  16. Carlton, S., Clopton, D., and Cappuzzo, K. A. Vitamin D deficiency: appropriate replenishment therapies and the effects of vitamin D toxicity. Consult Pharm 2010;25(3):171-177. PubMed
  17. Wang, H., Xia, N., Yang, Y., and Peng, D. Q. Influence of vitamin D supplementation on plasma lipid profiles: a meta-analysis of randomized controlled trials. Lipids Health Dis. 2012;11:42. PubMed
  18. Turner AN, Carr Reese P, Fields KS, Anderson J, Ervin M, Davis JA, Fichorova RN, Roberts MW, Klebanoff MA, Jackson RD. A blinded, randomized controlled trial of high-dose vitamin D supplementation to reduce recurrence of bacterial vaginosis. Am J Obstet G PubMed
  19. Weiner M, Epstein FH. Signs and symptoms of electrolyte disorders. Yale J Biol Med. 1970;43(2):76-109.
  20. 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
  21. Roth DE, Leung M, Mesfin E, Qamar H, Watterworth J, Papp E. Vitamin D supplementation during pregnancy: state of the evidence from a systematic review of randomised trials. BMJ. 2017;359:j5237. PubMed
  22. Murai IH, Fernandes AL, Sales LP, et al. Effect of a single high dose of vitamin D3 on hospital length of stay in patients with moderate to severe COVID-19: A randomized clinical trial. JAMA. 2021.
  23. Wang Z, Schuetz EG, Xu Y, Thummel KE. Interplay between vitamin D and the drug metabolizing enzyme CYP3A4. J Steroid Biochem Mol Biol 2013;136:54-8. PubMed
  24. Doyle D, Browne U, Brickley A, Murphy D. Vitamin D-induced hypercalcaemia and acute kidney injury in sarcoidosis. BMJ Case Rep 2023;16(1):e250580. PubMed
  25. Williamson A, Martineau AR, Sheikh A, Jolliffe D, Griffiths CJ. Vitamin D for the management of asthma. Cochrane Database Syst Rev 2023;2(2):CD011511. PubMed
  26. Kinesya E, Santoso D, Gde Arya N, et al. Vitamin D as adjuvant therapy for diabetic foot ulcers: Systematic review and meta-analysis approach. Clin Nutr ESPEN 2023;54:137-143. PubMed

See these in context on the Vitamin D monograph →

Willow Bark 12 references
  1. Chrubasik S, Eisenberg E, Balan E, et al. Treatment of low back pain exacerbations with willow bark extract: a randomized double-blind study. Am J Med 2000;109:9-14. PubMed
  2. Schmid B, Ludtke R, Selbmann HK, et al. Efficacy and tolerability of a standardized willow bark extract in patients with osteoarthritis: randomized placebo-controlled, double blind clinical trial. Phytother Res 2001;15:344-50. PubMed
  3. Biegert C, Wagner I, Ludtke R, et al. Efficacy and safety of willow bark extract in the treatment of osteoarthritis and rheumatoid arthritis: results of 2 randomized double-blind controlled trials. J Rheumatol 2004;31:2121-30.
  4. Unsworth J, d'Assis-Fonseca A, Beswick DT, Blake DR. Serum salicylate levels in a breast fed infant. Ann Rheum Dis 1987;46:638-9. PubMed
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  7. Schmid B, Kotter I, Heide L. Pharmacokinetics of salicin after oral administration of a standardised willow bark extract. Eur J Clin Pharmacol. 2001;57:387-91. PubMed
  8. Krivoy N, Pavlotzky E, Chrubasik S, et al. Effect of salicis cortex extract on human platelet aggregation. Planta Med 2001;67:209-12. PubMed
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  12. Sweeney, K. R., Chapron, D. J., Brandt, J. L., Gomolin, I. H., Feig, P. U., and Kramer, P. A. Toxic interaction between acetazolamide and salicylate: case reports and a pharmacokinetic explanation. Clin Pharmacol Ther 1986;40(5):518-524.

See these in context on the Willow Bark monograph →

Devil's Claw 18 references
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Shaw D, Leon C, Kolev S, Murray V. Traditional remedies and food supplements: a 5-year toxicological study (1991-1995). Drug Saf 1997;17:342-56.
  3. Chantre P, Cappelaere A, Leblan D, et al. Efficacy and tolerance or Harpagophytum procumbens versus diacerhein in treatment of osteoarthritis. Phytomedicine 2000;7:177-83.
  4. Chrubasik S, Thanner J, Kunzel O, et al. Comparison of outcome measures during treatment with the proprietary Harpagophytum extract doloteffin in patients with pain in the lower back, knee or hip. Phytomedicine 2002;9:181-94. PubMed
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  9. Chrubasik S, Kunzel O, Thanner J, et al. A 1-year follow-up after a pilot study with Doloteffin for low back pain. Phytomedicine 2005;12:1-9. PubMed
  10. Romiti N, Tramonti G, Corti A, Chieli E. Effects of Devil's Claw (Harpagophytum procumbens) on the multidrug transporter ABCB1/P-glycoprotein. Phytomedicine 2009;16:1095-100. PubMed
  11. Chrubasik, S., Junck, H., Breitschwerdt, H., Conradt, C., and Zappe, H. Effectiveness of Harpagophytum extract WS 1531 in the treatment of exacerbation of low back pain: a randomized, placebo-controlled, double- blind study. Eur.J Anaesthesiol. 1999;16(2 DOI
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  13. Belaiche P. Etude clinique de 630 cas d'artrose traites par le nebulisat aqueux d'Harpagophytum procumbens (Radix). Phytotherapy 1982;1:22-28.
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  15. Cuspidi C, Sala C, Tadic M, et al. Systemic hypertension induced by Harpagophytum procumbens (devil's claw): a case report. J Clin Hypertens (Greenwich) 2015;17(11):908-10.
  16. Mahomed IM, Ojewole JAO. Oxytocin-like effect of Harpagophytum procumbens [Pedaliacae] secondary root aqueous extract on rat isolated uterus. Afr J Trad CAM 2006;3(1):82-89.
  17. Carvalho RR, Donadel CD, Cortez AF, Valviesse VR, Vianna PF, Correa BB. J Bras Nefrol. 2017 Mar;39(1):79-81.
  18. Anon. Devil's claw root: ulcers and gastrointestinal bleeding. Prescrire Int 2013;22(144):296.

See these in context on the Devil's Claw 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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