Major interaction on record — check this product against your medications before combining. Check your meds →
Dietary supplement

H2PLX Ingredients & Drug Interactions

by Priority One Nutritional Supplements

H2PLX label
See full label image
Capsule Category: Other Combinations
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 H2PLX 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

H2PLX is a dietary supplement by Priority One Nutritional Supplements with 7 active ingredients. Its ingredients are commonly taken for cold sores (herpes labialis), genital herpes outbreaks, supporting protein and collagen formation.Based on those ingredients, 1,085 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Lithium, Vitamin A, Selenium. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against H2PLX by Priority One Nutritional Supplements

Ask about any prescription or over-the-counter medication and we check it for interactions with H2PLX by Priority One Nutritional Supplements — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of H2PLX by Priority One Nutritional Supplements

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 Aug 6, 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 7 of its 7 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

H2PLX contains 7 active ingredients. L-Lysine Hydrochloride is an amino acid studied for cold sores.

Vitamin C supports immune function and collagen formation. Vitamin A is a fat-soluble nutrient for skin and vision.

Olive extract comes from the olive fruit and leaf. Selenium is a mineral that acts as an antioxidant in the body.

Lithium is a trace element with neurological effects. Lemon Balm extract is derived from the lemon balm plant.

The product also contains inactive ingredients (rice chelate, maltodextrin, gum arabic, dicalcium phosphate, DL-alpha-tocopherol, corn starch, silicon dioxide, and a vegetarian capsule) used as fillers and binders.

Does it work?

Strong 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

This product doesn't appear to be marketed for a specific use, so we graded its ingredients' overall clinical evidence instead.

Strong

Strong clinical evidence supports its ingredients for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredients' overall clinical evidence instead.
  • On file: Vitamin A deficiency — rated "Effective" (Vitamin A) (Natural Medicines).
  • On file: Vitamin C deficiency — rated "Effective" (Vitamin C) (Natural Medicines).
  • On file: Selenium deficiency — rated "Likely Effective" (Selenium) (Natural Medicines).
  • On file: Aging skin — rated "Possibly Effective" (Vitamin A) (Natural Medicines).
  • On file: Anemia of chronic disease — rated "Possibly Effective" (Vitamin C) (Natural Medicines).

Evidence for these ingredients is mixed. L-Lysine is possibly effective for cold sores but has insufficient evidence for pressure ulcers, diabetic foot ulcers, or supporting child growth.

Vitamin C is effective for vitamin C deficiency and possibly effective for anemia of chronic disease, atrial fibrillation, cataracts, and exercise-related respiratory infections. Vitamin A is effective for vitamin A deficiency and possibly effective for oral leukoplakia, aging skin, measles, ulcerative colitis, and bronchopulmonary dysplasia.

Selenium is likely effective for selenium deficiency, possibly effective for Kashin-Beck disease and pre-eclampsia, and possibly ineffective for dyslipidemia. Olive extract and lemon balm extract have insufficient evidence for the conditions listed in our data.

The evidence, ingredient by ingredient Lysine Vitamin C Vitamin A Olive Selenium Lithium Lemon

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 7 of the 7 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 7 of 7.
  • General safety write-ups exist for 7 of 7.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Vitamin C and vitamin A are generally well tolerated at normal doses but can cause side effects at very high doses—vitamin C may cause kidney stones and diarrhea; vitamin A can cause liver damage and serious neurological problems. L-Lysine is generally well tolerated but high amounts may cause stomach upset and diarrhea; long-term safety is not well studied.

Selenium is safe at recommended amounts but excess can be toxic. Olive extract and lemon balm extract appear well tolerated in typical amounts, though concentrated supplements are less studied.

Lithium has a narrow safety margin and is concerning in pregnancy and breastfeeding—supplement forms are not well studied compared to prescription lithium, which requires blood monitoring. Regarding pregnancy: vitamin C at normal amounts is likely safe but avoid high-dose supplements; vitamin A and lithium should be avoided unless a doctor directs and monitors you; data on L-lysine, selenium, olive extract, and lemon balm extract in pregnancy is not on file, so talk with your doctor or pharmacist for personalized advice.

For breastfeeding: lithium should be avoided unless supervised by your doctor; normal amounts of vitamin C appear acceptable but avoid high-dose supplements; data on the other ingredients while breastfeeding is not on file.

Side effects, ingredient by ingredient Lysine Vitamin C Vitamin A Olive Selenium Lithium Lemon

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

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

Why this rating?
  • 6 of the 7 matched ingredients can interact with medications — Lysine, Lemon, Vitamin A, Vitamin C, Selenium, among others.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; seizure medications; immunosuppressants / transplant drugs; cancer treatments.
  • For scale: 1,086 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 this product, check with your doctor or pharmacist if you take any serotonergic drugs or antidepressants (Major risk with lithium), diuretics (Major risk with lithium), retinoid medications like tretinoin or isotretinoin (Major risk with vitamin A), blood thinners like warfarin, antiplatelet drugs, NSAIDs, or acetaminophen, hormone medications including birth control or hormone replacement therapy, chemotherapy drugs, barbiturates or other sedating medications, blood pressure medications (ACE inhibitors or calcium channel blockers), immunosuppressant drugs, seizure medications, or antifungal medications. The interaction categories identified span these types at Major, Moderate, and Minor severity levels.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with strong clinical evidence behind its ingredients' uses. Major medication interactions have been identified, and safety information is well characterized.

H2PLX combines several micronutrients and plant extracts, but the presence of lithium makes this a product that absolutely requires a conversation with your doctor or pharmacist before starting, especially if you take any psychiatric, heart, blood pressure, or blood-thinning medications. The vitamin A and vitamin C content also matter if you're on birth control, blood thinners, or chemotherapy.

If you take any prescription medications at all, check them against the interaction tool on this page first.

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

Assessment coverage: 7 of 7 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Sep 24, 2021.

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 H2PLX, straight from the product label.

Brand Priority One Nutritional Supplements
Barcode (UPC) 815354020631
Net contents 90 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD Sep 24, 2021
DSLD ID 255569
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegetarian, Adult (18 - 50 Years), Women (not pregnant or lactating)
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 H2PLX by Priority One Nutritional Supplements, 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 Vegetarian Capsule(s)
Maximum serving Sizes:
2 Vegetarian Capsule(s)
Servings per container
45
UPC/BARCODE
815354020631
IngredientAmount% DV
L-Lysine Hydrochloride150 mg--
Vitamin C250 mg417%
Vitamin A20800 IU416%
Olive extract50 mg--
Selenium800 mcg1143%
Lithium10 mg--
Lemon Balm extract250 mg--

Other ingredients: Rice Chelate, Maltodextrin, Gum Arabic, Dicalcium Phosphate, DL-Alpha-Tocopherol, Corn Starch, Silicon Dioxide, Vegetarian Capsule

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.
Precautions

Warning: Lithium should not be ingested by pregnant women.

Keep out of reach of children.

Consult your physician before using this product.

Suggested/Recommended/Usage/Directions

Recommendations: Take two (2) capsules daily or as directed by your physician.

Storage

Keep container tightly closed, store in a cool, dry place.

Formulation

Contains no preservatives. Bisphenol-A (BPA) & Phthalate Free

Vegetarian formulation

Seals/Symbols

GMP Certified

General Statements

Priority One Nutritional Supplements Inc since 1988

For professional use only.

FDA Statement of Identity

A Dietary Supplement

FDA Disclaimer Statement

This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.

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

See for yourself

H2PLX by Priority One Nutritional Supplements label

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

H2PLX 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 H2PLX by Priority One Nutritional Supplements

These are the 7 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Vegetarian Capsule(s) Dosage formCapsule Servings per container45 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.

L-Lysine Hydrochloride

Interacts with
1 drug
150 mg per serving

Lysine is an essential amino acid your body cannot make on its own, so it must come from food or supplements. People most often take extra lysine to t...

L-Lysine Hydrochloride monograph & interactions

Vitamin C

Interacts with
207 drugs
250 mg per serving Form: Ascorbic Acid

Vitamin C (ascorbic acid) is an essential nutrient your body needs but cannot make, so you must get it from food or supplements. It's important for im...

Vitamin C monograph & interactions

Vitamin A

Interacts with
387 drugs
20800 IU per serving Form: Vitamin A Acetate

Vitamin A is an essential nutrient important for vision, skin, immune function, and growth. Most people get enough from a balanced diet, and supplemen...

Vitamin A monograph & interactions

Olive extract

No known
interactions
50 mg per serving Form: Oleuropein

Olive comes from the same tree that gives us olives and olive oil, and its leaf and fruit contain antioxidant compounds like oleuropein and hydroxytyr...

Olive extract monograph & interactions

Selenium

Interacts with
321 drugs
800 mcg per serving Form: Selenium Aspartate, Sodium Selenite

Selenium is an essential trace mineral your body needs in small amounts for thyroid function, antioxidant defense, and immune health. Most people who...

Selenium monograph & interactions

Lithium

Interacts with
515 drugs
10 mg per serving Form: Lithium Carbonate, Lithium Orotate

Lithium is a naturally occurring metal that, in prescription form (lithium carbonate or citrate), is an FDA-approved, well-proven treatment for bipola...

Lithium monograph & interactions

Lemon Balm extract

Interacts with
1 drug
250 mg per serving Form: Rosemarinic Acid

Lemon is a common citrus fruit that is a good source of vitamin C and citric acid, and it is widely used in food, drinks, and home remedies. While it...

Lemon Balm extract monograph & interactions

Other (inactive) ingredients: Rice Chelate, Maltodextrin, Gum Arabic, Dicalcium Phosphate, DL-Alpha-Tocopherol, Corn Starch, Silicon Dioxide, Vegetarian Capsule. These complete the product’s ingredient list but are not active constituents.

Interaction report

H2PLX by Priority One Nutritional Supplements Drug Interactions

Want to check YOUR meds against H2PLX?

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
1,085Drugs
268 Major 809 Moderate 8 Minor

Ingredients driving the most interactions

Lithium 515
Vitamin A 387
Selenium 321
Vitamin C 207
L-Lysine Hydrochloride 1

Individual Drug Interactions

The ingredients in H2PLX interact with 1,085 drugs. Click any drug to see the details.

6 of the 7 ingredients in H2PLX interact with drugs. Each result below shows which ingredient is responsible. Lithium Vitamin A Selenium Vitamin C L-Lysine Hydrochloride Lemon Balm extract

Each ingredient & the kinds of drugs it affects

For each ingredient in H2PLX 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.

Lithium11 drug types · 515 drugs

Diuretic Drugs

Theoretically, taking lithium supplements with loop diuretics might increase lithium levels and adverse effects.
Thiazide diuretics and loop diuretics might reduce lithium excretion, particularly in sodium-restricted patients. If lithium is clinically indicated and other treatment options are unavailable or inadequate in patients using diuretics, lithium treatment can be initiated with extreme caution. Serum lithium should be measured frequently and the doses used should be the lowest dose ordinarily tolerated. It is unclear if this interaction would be clinically significant with the smaller doses found in lithium supplements.

Likelihood Probable Evidence D
Serotonergic Drugs

Theoretically, taking lithium supplements with serotonergic drugs might both mask and increase the risk of serotonin syndrome.
In a case report, a 67-year-old female with depression and bipolar disorder using lithium in combination with selective serotonin reuptake inhibitors (SSRIs) and other medications developed serotonin syndrome with symptoms of deep tendon hyperreflexia, muscle rigidity, tremor, and hyperthermia. However, agitation, one classical symptom of serotonin syndrome, was lacking. This was thought to be due to masking by lithium toxicity. Lithium can increase serotonin levels, thus, combining serotonergic drugs with lithium might increase the risk of serotonergic side effects including serotonin syndrome and cerebral vasoconstrictive disorders. It is unclear if this interaction would occur with the smaller doses found in lithium supplements.

Likelihood Probable Evidence D
Ace Inhibitors (Aceis)

Theoretically, taking lithium supplements with ACEIs might increase levels and adverse effects of lithium.
Concomitant administration of ACEIs with lithium may increase lithium concentrations. It is unclear if this interaction would be clinically significant with the smaller doses found in lithium supplements.

Likelihood Possible Evidence D
Anticonvulsants

Theoretically, taking lithium supplements with anticonvulsants might increase the risk of neurotoxicity.
Drugs such as carbamazepine and phenytoin seem to increase the risk of neurotoxicity. It is unclear if this interaction would occur with the smaller doses found in lithium supplements.

Likelihood Possible Evidence D
Antipsychotic Drugs

Theoretically, taking lithium supplements with antipsychotic drugs might increase the risk of encephalopathic syndrome.
Encephalopathic syndrome has been reported in multiple patients taking prescription lithium and antipsychotics concomitantly. Symptoms have included weakness and lethargy, fever, confusion, and extrapyramidal symptoms. In some patients, resulting brain damage was irreversible. Although there is no established causal relationship between these symptoms and the combination of lithium and antipsychotic medications, there is a theoretical relationship. It is unclear if this interaction would occur with the smaller doses found in lithium supplements.

Likelihood Possible Evidence D
Calcium Channel Blockers

Theoretically, taking lithium supplements with calcium channel blockers might reduce lithium levels and might also increase the risk of certain adverse effects.
Calcium channel blockers might reduce lithium concentrations. Monitor lithium levels with concurrent use. Calcium channel blockers might also increase the adverse neurological and gastrointestinal adverse effects of lithium. It is unclear if these interactions would occur with the smaller doses found in lithium supplements.

Likelihood Possible Evidence D
Methyldopa (Aldomet)

Theoretically, taking lithium supplements with methyldopa might increase the risk of lithium toxicity.
Concurrent use of methyldopa with lithium increases the risk of lithium toxicity. It is unclear if this interaction would be clinically significant with the smaller doses found in lithium supplements.

Likelihood Probable Evidence D
Methylxanthines

Theoretically, taking lithium supplements with methylxanthines might decrease lithium levels.
Xanthines such as aminophylline, caffeine, and theophylline (Theo-Dur, Theo-24, others) might increase the clearance of lithium. It is unclear if this interaction would be clinically significant with the smaller doses found in lithium supplements.

Likelihood Probable Evidence D
Nonsteroidal Anti-Inflammatory Drugs (Nsaids)

Theoretically, taking lithium supplements with NSAIDs might increase lithium levels and adverse effects.
NSAIDs can decrease the renal clearance of lithium and increase lithium levels. It is unclear if this interaction would be clinically significant with the smaller doses found in lithium supplements.

Likelihood Probable Evidence D
Phenothiazines

Theoretically, taking lithium supplements with phenothiazines might decrease the levels and clinical effects of phenothiazines.
Concomitant use of lithium with phenothiazines might reduce lithium concentrations. Lithium might also reduce phenothiazine concentrations, making the pharmacokinetic effect unpredictable. It is unclear if these interactions would occur with the smaller doses found in lithium supplements.

Likelihood Probable Evidence D
Skeletal Muscle Relaxants

Theoretically, taking lithium supplements with skeletal muscle relaxants might prolong neuromuscular blockade.
Lithium might prolong neuromuscular blockade. It is unclear if this interaction would occur with the smaller doses found in lithium supplements.

Likelihood Probable Evidence D
Lithium full monograph & interactions

Vitamin A4 drug types · 387 drugs

Retinoids

Concomitant use of retinoids with vitamin A supplements might produce supratherapeutic vitamin A levels.
Retinoids, which are vitamin A derivatives, could have additive toxic effects when taken with vitamin A supplements.

Likelihood Probable Evidence D
Hepatotoxic Drugs

Theoretically, taking high doses of vitamin A in combination with other potentially hepatotoxic drugs might increase the risk of liver disease.
The tolerable upper intake level (UL) is the highest level of intake that is likely to pose no risk of adverse effects. Doses of vitamin A above the UL can cause hepatotoxicity, ranging from elevated liver enzymes to liver failure.

Likelihood Possible Evidence C
Tetracycline Antibiotics

Theoretically, taking tetracycline antibiotics with high doses of vitamin A can increase the risk of pseudotumor cerebri.
Benign intracranial hypertension (pseudotumor cerebri) can occur with tetracyclines and with acute or chronic vitamin A toxicity. Case reports suggest that taking tetracyclines and vitamin A concurrently can increase the risk of this condition. Avoid high doses of vitamin A in people taking tetracyclines chronically.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, high doses of vitamin A could increase the risk of bleeding with warfarin.
Vitamin A toxicity is associated with hemorrhage and hypoprothrombinemia, possibly due to vitamin K antagonism. Advise patients taking warfarin to avoid doses of vitamin A above the tolerable upper intake level of 10,000 IU/day for adults.

Likelihood Possible Evidence D
Vitamin A full monograph & interactions

Selenium6 drug types · 321 drugs

Anticoagulant/Antiplatelet Drugs

Selenium may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Clinical research suggests that taking selenium 10 mcg/kg/day can increase bleeding times by increasing prostacyclin production, which inhibits platelet activity. Other clinical research suggests that taking selenium 75 mcg daily, in combination with ascorbic acid 600 mg, alpha-tocopherol 300 mg, and beta-carotene 27 mg, reduces platelet aggregation.

Likelihood Possible Evidence D
Barbiturates

Theoretically, selenium might prolong the sedating effects of barbiturates.
Laboratory research suggests that selenium can inhibit the hepatic metabolism of barbiturates. Selenium seems to prolong the sedative effect of pentobarbital in animal models.

Likelihood Possible Evidence D
Immunosuppressants

Theoretically, selenium supplementation may reduce the effectiveness of immunosuppressant therapy.
In vitro research and preliminary clinical evidence suggests that selenium may stimulate the immune system.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, selenium might interfere with warfarin activity.
Animal research suggests that selenium can increase warfarin activity. Selenium might interact with warfarin by displacing it from albumin binding sites, reducing its metabolism in the liver, or by decreasing production of vitamin K-dependent clotting factors. Selenium can also prolong bleeding times in humans by increasing prostacyclin production, which inhibits platelet activity.

Likelihood Possible Evidence D
Contraceptive Drugs

Contraceptive drugs might increase levels of selenium, although the clinical significance of this effect is unclear.
Some research suggests that oral contraceptives increase serum selenium levels in women taking oral contraceptives; however, other research shows no change in selenium levels. It is suggested that an increase could be due to increased carrier proteins, indicating a redistribution of selenium rather than a change in total body selenium.

Likelihood Possible Evidence B
Niacin

Selenium might reduce the beneficial effects of niacin on high-density lipoprotein (HDL) levels.
A combination of niacin and simvastatin (Zocor) effectively raises HDL cholesterol levels in patients with coronary disease and low HDL levels. Clinical research shows that taking a combination of antioxidants (vitamin C, vitamin E, beta-carotene, and selenium) along with niacin and simvastatin (Zocor) attenuates this rise in HDL, specifically the HDL-2 and apolipoprotein A1 fractions, by more than 50% in patients with coronary disease. It is not known whether this adverse effect is due to a single antioxidant such as selenium, or to the combination. It also is not known whether it will occur in other patient populations.

Likelihood Possible Evidence A
Selenium full monograph & interactions

Vitamin C13 drug types · 207 drugs

Alkylating Agents

Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
The use of antioxidants like vitamin C during chemotherapy is controversial. There is concern that antioxidants could reduce the activity of chemotherapy drugs that generate free radicals, such as cyclophosphamide, chlorambucil, carmustine, busulfan, and thiotepa. In contrast, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin C have on chemotherapy.

Likelihood Possible Evidence D
Aluminum

Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Research in animals and humans shows that vitamin C increases aluminum absorption, theoretically by chelating aluminum and keeping it in solution where it is available for absorption. In people with normal renal function, urinary excretion of aluminum will likely increase, making aluminum retention and toxicity unlikely. Patients with renal failure who take aluminum-containing compounds such as phosphate binders should avoid vitamin C supplements in doses above the recommended dietary allowances.

Likelihood Probable Evidence B
Antitumor Antibiotics

Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.
The use of antioxidants like vitamin C during chemotherapy is controversial. There is concern that antioxidants could reduce the activity of chemotherapy drugs which generate free radicals, such as doxorubicin. In contrast, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effects, if any, antioxidants such as vitamin C have on chemotherapy.

Likelihood Possible Evidence D
Estrogens

Vitamin C might increase blood levels of estrogens.
Increases in plasma estrogen levels of up to 55% occur under some circumstances when vitamin C is taken concurrently with oral contraceptives or hormone replacement therapy, including topical products. It is suggested that vitamin C prevents oxidation of estrogen in the tissues, regenerates oxidized estrogen, and reduces sulfate conjugation of estrogen in the gut wall. When tissue levels of vitamin C are high, these processes are already maximized and supplemental vitamin C does not have any effect on estrogen levels. Increases in plasma estrogen levels may occur when patients who are deficient in vitamin C take supplements. Monitor these patients for estrogen-related side effects.

Likelihood Probable Evidence B
Fluphenazine (Prolixin)

Theoretically, vitamin C might decrease levels of fluphenazine.
In one patient there was a clinically significant decrease in fluphenazine levels when vitamin C (500 mg twice daily) was started. The mechanism is not known, and there is no further data to confirm this interaction.

Likelihood Possible Evidence D
Indinavir (Crixivan)

Vitamin C can modestly reduce indinavir levels.
One pharmacokinetic study shows that taking vitamin C 1 gram orally once daily along with indinavir 800 mg orally three times daily reduces the area under the concentration-time curve of indinavir by 14%. The mechanism of this interaction is unknown, but it is unlikely to be clinically significant in most patients. The effect of higher doses of vitamin C on indinavir levels is unknown.

Likelihood Probable Evidence B
Levothyroxine (Synthroid, Others)

Vitamin C can increase levothyroxine absorption.
Two clinical studies in adults with poorly controlled hypothyroidism show that swallowing levothyroxine with a glass of water containing vitamin C 500-1000 mg in solution reduces thyroid stimulating hormone (TSH) levels and increases thyroxine (T4) levels when compared with taking levothyroxine alone. This suggests that vitamin C increases the oral absorption of levothyroxine, possibly due to a reduction in pH.

Likelihood Probable Evidence B
Warfarin (Coumadin)

High-dose vitamin C might reduce the levels and effectiveness of warfarin.
Vitamin C in high doses may cause diarrhea and possibly reduce warfarin absorption. There are reports of two people who took up to 16 grams daily of vitamin C and had a reduction in prothrombin time. Lower doses of 5-10 grams daily can also reduce warfarin absorption. In many cases, this does not seem to be clinically significant. However, a case of warfarin resistance has been reported for a patient who took vitamin C 500 mg twice daily. Cessation of vitamin C supplementation resulted in a rapid increase in international normalized ratio (INR). Tell patients taking warfarin to avoid taking vitamin C in excessively high doses (greater than 10 grams daily). Lower doses may be safe, but the anticoagulation activity of warfarin should be monitored. Patients who are stabilized on warfarin while taking vitamin C should avoid adjusting vitamin C dosage to prevent the possibility of warfarin resistance.

Likelihood Possible Evidence D
Acetaminophen (Tylenol, Others)

High-dose vitamin C might slightly prolong the clearance of acetaminophen.
A small pharmacokinetic study in healthy volunteers shows that taking high-dose vitamin C (3 grams) 1.5 hours after taking acetaminophen 1 gram slightly increases the apparent half-life of acetaminophen from around 2.3 hours to 3.1 hours. Ascorbic acid competitively inhibits sulfate conjugation of acetaminophen. However, to compensate, elimination of acetaminophen glucuronide and unconjugated acetaminophen increases. This effect is not likely to be clinically significant.

Likelihood Probable Evidence B
Aspirin

Acidification of the urine by vitamin C might increase aspirin levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction is not clinically significant.

Likelihood Possible Evidence B
Choline Magnesium Trisalicylate (Trilisate)

Acidification of the urine by vitamin C might increase choline magnesium trisalicylate levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction probably is not clinically significant.

Likelihood Possible Evidence B
Niacin

Vitamin C might decrease the beneficial effects of niacin on high-density lipoprotein (HDL) cholesterol levels.
A combination of niacin and simvastatin (Zocor) effectively raises HDL cholesterol levels in patients with coronary disease and low HDL levels. Clinical research shows that taking a combination of antioxidants (vitamin C, vitamin E, beta-carotene, and selenium) along with niacin and simvastatin (Zocor) attenuates this rise in HDL, specifically the HDL-2 and apolipoprotein A1 fractions, by more than 50% in patients with coronary disease. It is not known whether this adverse effect is due to a single antioxidant such as vitamin C, or to the combination. It also is not known whether it will occur in other patient populations.

Likelihood Possible Evidence A
Salsalate (Disalcid)

Acidification of the urine by vitamin C might increase salsalate levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams/day vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction probably is not clinically significant.

Likelihood Possible Evidence B
Vitamin C full monograph & interactions

L-Lysine Hydrochloride1 drug type · 1 drug

5-Ht4 Agonists

Theoretically, lysine may reduce the effects of 5-HT4 agonists.
Animal research suggests that L-lysine is a partial serotonin receptor 4 (5-HT4) antagonist and inhibits diarrhea induced by the 5-HT4 agonist, 5-hydroxytryptophane.

Likelihood Unlikely Evidence D
L-Lysine Hydrochloride full monograph & interactions

Lemon Balm extract1 drug type · 1 drug

Itraconazole (Sporanox)

Theoretically, taking itraconazole capsules or tablets with a beverage containing lemon might increase the levels and clinical effects of itraconazole.
In one case report, dissolving itraconazole tablets in a small amount of specific beverages containing lemon prior to administration increased the level of itraconazole in a lung transplant patient. In this case, the increased bioavailability was desirable and was likely due to improved tablet dissolution in the acidic beverage.

Likelihood Possible Evidence D
Lemon Balm extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for H2PLX, from the product label.

Priority One Nutritional Supplements

See all Priority One Nutritional Supplements products
Name
Priority One Nutritional Supplements, Inc.
Web Address
www.priorityonevitamins.com
Pharmacist Counseling Corner

H2PLX by Priority One Nutritional Supplements: Common Questions

Does H2PLX by Priority One Nutritional Supplements interact with any medications?
Yes. Based on its ingredients, H2PLX has a known interaction with 1,085 medications, including 268 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
H2PLX contains 7 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 this product actually help with cold sores?
L-Lysine in this product is possibly effective for cold sores based on the evidence we hold, meaning there's some research support but it's not definitive. Results vary by person. If you're considering it for that purpose, give it a reasonable trial and see how you respond.
Can I take this while I'm pregnant?
Not without talking to your doctor first. Vitamin A in this product should be avoided in pregnancy unless your doctor specifically directs it because high doses can cause birth defects. Lithium should also be avoided in pregnancy unless your doctor monitors you closely. Data on the other ingredients during pregnancy isn't on file, so discuss this product with your doctor or pharmacist before starting.
Is this safe if I'm breastfeeding?
Lithium should not be used while breastfeeding unless your doctor supervises it, since it passes into breast milk. Normal amounts of vitamin C appear acceptable. Data on the other ingredients while breastfeeding isn't on file—check with your doctor or pharmacist for your individual situation.
What's the most important thing to know before taking this?
This product contains lithium, which interacts with many common medications—particularly psychiatric drugs, blood pressure meds, diuretics, and blood thinners. If you take any prescription medication, you must check it against our interaction tool before starting. Lithium also requires monitoring and has a narrow safety window.
What side effects might I experience?
At typical doses, most people tolerate these ingredients well. L-Lysine and vitamin C may cause stomach upset or diarrhea in some people. Selenium can cause headache, rash, or stomach discomfort. Lemon balm and olive extract may cause heartburn or stomach discomfort in some people. High doses of vitamin A or vitamin C can cause more serious effects, so stick to the recommended dose.
Are there any ingredients in this product I should know aren't checked for interactions?
Olive extract wasn't checked for interactions—we don't hold interaction data for it. The other active ingredients have been reviewed. If you're concerned about any specific ingredient or medication combination, run it through the search tool on this page or ask your pharmacist.

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.

H2PLX label
Go deeper

The Full Monographs Behind H2PLX’s Ingredients

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

Herb & supplement monograph

Lysine

Interacts with 1 drug

Lysine is an essential amino acid your body cannot make on its own, so it must come from food or supplements. People most often take extra lysine to try to prevent or shorten cold sores, but...

Read the full Lysine monograph → Herb & supplement monograph

Vitamin C

Interacts with 207 drugs

Vitamin C (ascorbic acid) is an essential nutrient your body needs but cannot make, so you must get it from food or supplements. It's important for immune function, collagen, and acts as an...

Read the full Vitamin C monograph → Herb & supplement monograph

Vitamin A

Interacts with 387 drugs

Vitamin A is an essential nutrient important for vision, skin, immune function, and growth. Most people get enough from a balanced diet, and supplements are mainly useful for correcting a tr...

Read the full Vitamin A monograph → Herb & supplement monograph

Olive

Olive comes from the same tree that gives us olives and olive oil, and its leaf and fruit contain antioxidant compounds like oleuropein and hydroxytyrosol. Olive oil as part of a Mediterrane...

Read the full Olive monograph → Herb & supplement monograph

Selenium

Interacts with 321 drugs

Selenium is an essential trace mineral your body needs in small amounts for thyroid function, antioxidant defense, and immune health. Most people who eat a varied diet get enough, and supple...

Read the full Selenium monograph → Herb & supplement monograph

Lithium

Interacts with 515 drugs

Lithium is a naturally occurring metal that, in prescription form (lithium carbonate or citrate), is an FDA-approved, well-proven treatment for bipolar disorder. Low-dose supplement forms li...

Read the full Lithium monograph → Herb & supplement monograph

Lemon

Interacts with 1 drug

Lemon is a common citrus fruit that is a good source of vitamin C and citric acid, and it is widely used in food, drinks, and home remedies. While it can support hydration and a healthy diet...

Read the full Lemon monograph →
Sources

Sources & How We Checked

H2PLX'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 155 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.

Lysine 7 references
  1. Thein DJ, Hurt WC. Lysine as a prophylactic agent in the treatment of recurrent herpes simplex labialis. Oral Surg Oral Med Oral Pathol 1984;58:659-66. PubMed
  2. McCune MA, Perry HO, Muller SA, O'Fallon WM. Treatment of recurrent herpes simplex infections with L-lysine monohydrochloride. Cutis 1984;34:366-73.
  3. DiGiovanna JJ, Blank H. Failure of lysine in frequently recurrent herpes simplex infection. Treatment and prophylaxis. Arch Dermatol 1984;120:48-51. DOI
  4. Milman N, Scheibel J, Jessen O. Lysine prophylaxis in recurrent herpes simplex labialis: a double-blind, controlled crossover study. Acta Derm Venereol 1980;60:85-7.
  5. Griffith RS, Walsh DE, Myrmel KH, et al. Success of L-lysine therapy in frequently recurrent herpes simplex infection. Treatment and prophylaxis. Dermatologica 1987;175:183-90. DOI
  6. Lo JC, Chertow GM, Rennke H, Seifter JL. Fanconi's syndrome and tubulointerstitial nephritis in association with L-lysine ingestion. Am J Kidney Dis 1996;28:614-7. PubMed
  7. Smriga M, Torii K. L-Lysine acts like a partial serotonin receptor 4 antagonist and inhibits serotonin-mediated intestinal pathologies and anxiety in rats. Proc Natl Acad Sci U S A. 2003 Dec 23;100(26):15370-5.

See these in context on the Lysine monograph →

Vitamin C 51 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Back DJ, Breckenridge AM, MacIver M, et al. Interaction of ethinyloestradiol with ascorbic acid in man. Br Med J (Clin Res Ed) 1981;282:1516.
  3. Morris JC, Beeley L, Ballantine N. Interaction of ethinyloestradiol with ascorbic acid in man [letter]. Br Med J (Clin Res Ed) 1981;283:503.
  4. Labriola D, Livingston R. Possible interactions between dietary antioxidants and chemotherapy. Oncology 1999;13:1003-8.
  5. Dwyer JH, Merz NB, Shirocre AM, et al. Progression of early atherosclerosis and intake of vitamin C and vitamin E from supplements and food. The Los Angeles Atherosclerosis Study. 41st Annual Conference on Cardiovascular Disease Epidemiology and Prevent
  6. Levine M, Rumsey SC, Daruwala R, et al. Criteria and recommendations for vitamin C intake. JAMA 1999;281:1415-23. PubMed
  7. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  8. Segal S, Kaminski S. Drug-nutrient interactions. American Druggist 1996 Jul;42-8.
  9. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000. Available at: http://www.nap.edu/books/0309069351/html/.
  10. Houston JB, Levy G. Drug biotransformation interactions in man VI: Acetaminophen and ascorbic acid. J Pharm Sci 1976;65:1218-21. PubMed
  11. Brown BG, Zhao XQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med 2001;345:1583-93. DOI
  12. Rosenthal G. Interaction of ascorbic acid and warfarin. JAMA 1971;215:1671. DOI
  13. Hume R, Johnstone JM, Weyers E. Interaction of ascorbic acid and warfarin. JAMA 1972;219:1479. DOI
  14. Smith EC, Skalski RJ, Johnson GC, Rossi GV. Interaction of ascorbic acid and warfarin. JAMA 1972;221:1166. DOI
  15. Traxer O, Huet B, Poindexter J, et al. Effect of ascorbic acid consumption on urinary stone risk factors. J Urol 2003;170:397-401.. PubMed
  16. Domingo JL, Gomez M, Llobet JM, Richart C. Effect of ascorbic acid on gastrointestinal aluminum absorption (letter). Lancet 1991;338:1467.
  17. Domingo JL, Gomez M, Llobet JM, Corbella J. Influence of some dietary constituents on aluminum absorption and retention in rats. Kidney Int 1991;39:598-601. PubMed
  18. Partridge NA, Regnier FE, White JL, Hem SL. Influence of dietary constituents on intestinal absorption of aluminum. Kidney Int 1989;35:1413-7. PubMed
  19. Mc Leod DC, Nahata MC. Inefficacy of ascorbic acid as a urinary acidifier (letter). N Engl J Med 1977;296:1413. DOI
  20. Hansten PD, Hayton WL. Effect of antacid and ascorbic acid on serum salicylate concentration. J Clin Pharmacol 1980;20:326-31. PubMed
  21. Dysken MW, Cumming RJ, Channon RA, Davis JM. Drug interaction between ascorbic acid and fluphenazine. JAMA 1979;241:2008. DOI
  22. Vihtamaki T, Parantainen J, Koivisto AM, et al. Oral ascorbic acid increases plasma oestradiol during postmenopausal hormone replacement therapy. Maturitas 2002;42:129-35. PubMed
  23. Slain D, Amsden JR, Khakoo RA, et al. Effect of high-dose vitamin C on the steady-state pharmacokinetics of the protease inhibitor indinavir in healthy volunteers. Pharmacotherapy 2005;25:165-70. PubMed
  24. Cheung MC, Zhao XQ, Chait A, et al. Antioxidant supplements block the response of HDL to simvastatin-niacin therapy in patients with coronary artery disease and low HDL. Arterioscler Thromb Vasc Biol 2001;21:1320-6. PubMed
  25. Feetam CL, Leach RH, Meynell MJ. Lack of a clinically important interaction between warfarin and ascorbic acid. Toxicol Appl Pharmacol 1975;31:544-7. PubMed
  26. Weintraub M, Griner PF. Warfarin and ascorbic acid: lack of evidence for a drug interaction. Toxicol Appl Pharmacol 1974;28:53-6. PubMed
  27. Lee DH, Folsom AR, Harnack L, et al. Does supplemental vitamin C increase cardiovascular disease risk in women with diabetes? Am J Clin Nutr 2004;80:1194-200. PubMed
  28. Taylor EN, Stampfer MJ, Curhan GC. Dietary factors and the risk of incident kidney stones in men: new insights after 14 years of follow-up. J Am Soc Nephrol 2004;15:3225-32. PubMed
  29. Ward NC, Hodgson JM, Croft KD, et al. The combination of vitamin C and grape-seed polyphenols increases blood pressure: a randomized, double-blind, placebo-controlled trial. J Hypertens 2005;23:427-34.. PubMed
  30. Prasad KN. Rationale for using high-dose multiple dietary antioxidants as an adjunct to radiation therapy and chemotherapy. J Nutr 2004;134:3182S-3S. PubMed
  31. Conklin KA. Cancer chemotherapy and antioxidants. J Nutr 2004;134:3201S-3204S. PubMed
  32. Fairweather-Tait S, Hickson K, McGaw B, et al. Orange juice enhances aluminium absorption from antacid preparation. Eur J Clin Nutr. 1994;48(1):71-3.
  33. Gruenwald, J., Graubaum, H. J., Busch, R., and Bentley, C. Safety and tolerance of ester-C compared with regular ascorbic acid. Adv.Ther. 2006;23(1):171-178.
  34. Rahimi, R., Nikfar, S., Rezaie, A., and Abdollahi, M. A meta-analysis on the efficacy and safety of combined vitamin C and E supplementation in preeclamptic women. Hypertens.Pregnancy. 2009;28(4):417-434. PubMed
  35. Einerson, B., Nathorn, C., Kitiyakara, C., Sirada, M., and Thamlikitkul, V. The efficacy of ascorbic acid in suboptimal responsive anemic hemodialysis patients receiving erythropoietin: a meta-analysis. J Med.Assoc.Thai. 2011;94 Suppl 1:S134-S146.
  36. Li, G., Li, L., Yu, C., and Chen, L. Effect of vitamins C and E supplementation on Helicobacter pylori eradication: a meta-analysis. Br.J Nutr 2011;106(11):1632-1637.
  37. Chen X, Shen L, Gu X, et al. High-dose supplementation with vitamin C--induced pediatric urolithiasis: the first case report in a child and literature review. Urology. 2014;84(4):922-4. PubMed
  38. Sattar A, Willman JE, Kolluri R. Possible warfarin resistance due to interaction with ascorbic acid: case report and literature review. Am J Health Syst Pharm. 2013;70(9):782-6. PubMed
  39. Yaich S, Chaabouni Y, Charfeddine K, et al. Secondary oxalosis due to excess vitamin C intake: a cause of graft loss in a renal transplant recipient. Saudi J Kidney Dis Transpl. 2014;25(1):113-6. PubMed
  40. 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
  41. Rumbold A, Ota E, Nagata C, Shahrook S, Crowther CA. Vitamin C supplementation in pregnancy. Cochrane Database Syst Rev. 2015;(9):CD004072. PubMed
  42. Seo MS, Kim JK, Shim JY. High-dose vitamin C promotes regression of multiple pulmonary metastases originating from hepatocellular carcinoma. Yonsei Med J. 2015;56(5):1449-52. PubMed
  43. Skelin M, Lucijanic T, Amidzic Klaric D, et al. Factors Affecting Gastrointestinal Absorption of Levothyroxine: A Review. Clin Ther. 2017 Feb;39(2):378-403. PubMed
  44. Jiang K, Tang K, Liu H, Xu H, Ye Z, Chen Z. Ascorbic acid supplements and kidney stones incidence among men and women: a systematic review and meta-analysis. Urol J. 2019;16(2):115-120.
  45. Thomas S, Patel D, Bittel B, et al. Effect of High-Dose Zinc and Ascorbic Acid Supplementation vs Usual Care on Symptom Length and Reduction Among Ambulatory Patients With SARS-CoV-2 Infection: The COVID A to Z Randomized Clinical Trial. JAMA Netw Open. 2 PubMed
  46. Giffen MA, McLemore JL. Hyperoxalosis Secondary to Intravenous Vitamin C Administration as a Non-Allopathic Treatment for Cancer. Acad Forensic Pathol 2019;9(1-2):118-126. PubMed
  47. Maike A, Sturgill D, Gallan A. Oxalate Nephropathy in a Renal Transplant Recipient After Receiving High Dose Ascorbic Acid. Am J Med Sci 2021. PubMed
  48. Shen ZY, Chen YR, Wang MC, Chang SS. High-dose vitamin C-induced acute oxalate nephropathy in a renal transplant recipient: a case report and literature review. Asian J Surg 2022. PubMed
  49. Yanase F, Spano S, Maeda A, et al. Mega-dose sodium ascorbate: a pilot, single-dose, physiological effect, double-blind, randomized, controlled trial. Crit Care 2023;27(1):371. PubMed
  50. Sharma Y, Sumanadasa S, Shahi R, et al. Efficacy and safety of vitamin C supplementation in the treatment of community-acquired pneumonia: a systematic review and meta-analysis with trial sequential analysis. Sci Rep 2024;14(1):11846. PubMed
  51. Pejcic AV, Petrovic NZ, Djordjic MD, Milosavljevic MN. Vitamin C Levels in Pregnant Women and the Efficacy of Vitamin C Supplements in Preventing Premature Rupture of Membranes: A Systematic Review and Meta-Analysis. Balkan Med J 2024;41(4):248-260. PubMed

See these in context on the Vitamin C monograph →

Vitamin A 31 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Griffiths JK. The vitamin A paradox. J Pediatr 2000;137:604-7.. PubMed
  3. Hardman JG, Limbird LL, Molinoff PB, eds. Goodman and Gillman's The Pharmacological Basis of Therapeutics, 9th ed. New York, NY: McGraw-Hill, 1996.
  4. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  5. FDA Talk Paper. Vitamin A and birth defects (T95-56). Food and Drug Administration, U.S. Department of Health and Human Services, Rockville, MD. October 6, 1995.
  6. Russell RM. The vitamin A spectrum: from deficiency to toxicity. Am J Clin Nutr 2000;71:878-84. PubMed
  7. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
  8. Feskanich D, Singh V, Willett WC, Colditz GA. Vitamin A intake and hip fractures among postmenopausal women. JAMA 2002;287:47-54. PubMed
  9. Melhus H, Michaelsson K, Kindmark A, et al. Excessive dietary intake of vitamin A is associated with reduced bone mineral density and increased risk for hip fracture. Ann Intern Med 1998;129:770-8. PubMed
  10. Michaelsson K, Lithell H, Vessby B, Melhus H. Serum retinol levels and the risk of fracture. N Engl J Med 2003;348:287-94.. PubMed
  11. Botterweck AA, van den Brandt PA, Goldbohm RA. Vitamins, carotenoids, dietary fiber, and the risk of gastric carcinoma: results from a prospective study after 6.3 years of follow-up. Cancer 2000;88:737-48.. DOI
  12. Meyskens FL Jr, Graham V, Chvapil M, et al. A phase I trial of beta-all-trans-retinoic acid delivered via a collagen sponge and a cervical cap for mild or moderate intraepithelial cervical neoplasia. J Natl Cancer Inst 1983;71:921-5..
  13. Hathcock JN, Hattan DG, Jenkins MY, et al. Evaluation of vitamin A toxicity. Am J Clin Nutr 1990;52:183-202.. PubMed
  14. Walters BN, Gubbay SS. Tetracycline and benign intracranial hypertension: report of five cases. Br Med J 1981;282:19-20.. PubMed
  15. Pearson MG, Littlewood SM, Bowden AN. Tetracycline and benign intracranial hypertension (letter). Br Med J 1981;282:568-9.. PubMed
  16. Azais-Braesco V, Pascal G. Vitamin A in pregnancy: requirements and safety limits. Am J Clin Nutr 2000;71:1325S-33S. PubMed
  17. Smedts HP, de Vries JH, Rakhshandehroo M, et al. High maternal vitamin E intake by diet or supplements is associated with congenital heart defects in the offspring. BJOG 2009;116:416-23. PubMed
  18. Grotto, I., Mimouni, M., Gdalevich, M., and Mimouni, D. Vitamin A supplementation and childhood morbidity from diarrhea and respiratory infections: a meta-analysis. J Pediatr 2003;142(3):297-304. PubMed
  19. Mahalanabis, D., Lahiri, M., Paul, D., Gupta, S., Gupta, A., Wahed, M. A., and Khaled, M. A. Randomized, double-blind, placebo-controlled clinical trial of the efficacy of treatment with zinc or vitamin A in infants and young children with severe acute l
  20. Long, K. Z., Montoya, Y., Hertzmark, E., Santos, J. I., and Rosado, J. L. A double-blind, randomized, clinical trial of the effect of vitamin A and zinc supplementation on diarrheal disease and respiratory tract infections in children in Mexico City, Mex
  21. Fritz, H., Kennedy, D., Fergusson, D., Fernandes, R., Doucette, S., Cooley, K., Seely, A., Sagar, S., Wong, R., and Seely, D. Vitamin A and retinoid derivatives for lung cancer: a systematic review and meta analysis. PLoS.One. 2011;6(6):e21107. PubMed
  22. Mayo-Wilson, E., Imdad, A., Herzer, K., Yakoob, M. Y., and Bhutta, Z. A. Vitamin A supplements for preventing mortality, illness, and blindness in children aged under 5: systematic review and meta-analysis. BMJ 2011;343:d5094. PubMed
  23. Mazumder S, Taneja S, Bhatia K, Yoshida S, Kaur J, Dube B, Toteja GS, Bahl R, Fontaine O, Martines J, Bhandari N; Neovita India Study Group. Efficacy of early neonatal supplementation with vitamin A to reduce mortality in infancy in Haryana, India (Neovit
  24. Baineni R, Gulati R, Delhi CK. Vitamin A toxicity presenting as bone pain. Arch Dis Child. 2017;102(6):556-8. PubMed
  25. Darlow BA, Graham PJ, Rojas-Reyes MX. Vitamin A supplementation to prevent mortality and short- and long-term morbidity in very low birth weight infants. Cochrane Database Syst Rev. 2016;(8):CD000501. PubMed
  26. Haider BA, Sharma R, Bhutta ZA. Neonatal vitamin A supplementation for the prevention of mortality and morbidity in term neonates in low and middle income countries. Cochrane Database Syst Rev. 2017;2:CD006980. PubMed
  27. Mohammad YM, Raslan IR, Al-Hussain FA. Idiopathic Intracranial Hypertension Induced by Topical Application of Vitamin A. J Neuroophthalmol. 2016;36(4):412-3. PubMed
  28. Masnadi Shirazi K, Nikniaz Z, Masnadi Shirazi A, Rohani M. Vitamin A supplementation decreases disease activity index in patients with ulcerative colitis: A randomized controlled clinical trial. Complement Ther Med. 2018 Dec;41:215-219. PubMed
  29. Ding Y, Hu P, Yang Y, et al. Impact of maternal daily oral low-dose vitamin A supplementation on the mother-infant pair: a randomised placebo-controlled trial in China. Nutrients 2021;13(7):2370. PubMed
  30. Knapik JJ, Hoedebecke SS. Vitamin A and bone fractures: systematic review and meta-analysis. J Spec Oper Med 2021;21(2):100-7. PubMed
  31. Imdad A, Mayo-Wilson E, Haykal MR, et al. Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age. Cochrane Database Syst Rev 2022;3(3):CD008524. PubMed

See these in context on the Vitamin A monograph →

Olive 2 references
  1. Liccardi G, D'Amato M, D'Amato G. Oleaceae pollinosis: a review. Int Arch Allergy Immunol 1996;111:210-7. PubMed
  2. Somerville V, Moore R, Braakhuis A. The effect of olive leaf extract on upper respiratory illness in high school athletes: A randomised control trial. Nutrients. 2019;11(2). pii: E358. PubMed

See these in context on the Olive monograph →

Selenium 36 references
  1. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000. Available at: http://www.nap.edu/books/0309069351/html/.
  2. Brown BG, Zhao XQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med 2001;345:1583-93. DOI
  3. Trafikowska U, Zachara BA, Wiacek M, et al. Selenium supply and glutathione peroxidase activity in breastfed Polish infants. Acta Paediatr 1996;85:1143-5. PubMed
  4. Duffield-Lillico AJ, Slate EH, Reid ME, et al. Selenium supplementation and secondary prevention of nonmelanoma skin cancer in a randomized trial. J Natl Cancer Inst 2003;95:1477-81.. PubMed
  5. Cheung MC, Zhao XQ, Chait A, et al. Antioxidant supplements block the response of HDL to simvastatin-niacin therapy in patients with coronary artery disease and low HDL. Arterioscler Thromb Vasc Biol 2001;21:1320-6. PubMed
  6. Schiavon R, Freeman GE, Guidi GC, et al. Selenium enhances prostacyclin production by cultured endothelial cells: possible explanation for increased bleeding times in volunteers taking selenium as a dietary supplement. Thromb Res 1984;34:389-96. PubMed
  7. Davila JC, Edds GT, Osuna O, Simpson CF. Modification of the effects of aflatoxin B1 and warfarin in young pigs given selenium. Am J Vet Res 1983;44:1877-83. DOI
  8. Heese HD, Lawrence MA, Dempster WS, Pocock F. Reference concentrations of serum selenium and manganese in healthy nulliparas. S Afr Med J 1988;73:163-5.
  9. Lloyd B, Lloyd RS, Clayton BE. Effect of smoking, alcohol and other factors on the selenium status of a healthy population. J Epidemiol Commun Health 1983;37:213-7. PubMed
  10. Capel ID, Jenner M, Williams DC, et al. The effect of prolonged oral contraceptive steroid use on erythrocyte glutathione peroxidase activity. J Steroid Biochem 1981;14:729-32. PubMed
  11. Contempre B, Dumont JE, Ngo B, et al. Effect of selenium supplementation in hypothyroid subjects of an iodine and selenium deficient area: the possible danger of indiscriminate supplementation of iodine-deficient subjects with selenium. J Clin Endocrinol PubMed
  12. Hofbauer LC, Spitzweg C, Magerstadt RA, Heufelder AE. Selenium-induced thyroid dysfunction. Postgrad Med J 1997;73:103-4. PubMed
  13. Debski B, Milner JA. Dietary selenium supplementation prolongs pentobarbital induced hypnosis. J Nutr Biochem 2004;15:548-53. PubMed
  14. Ishikawa M, Sasaki M, Koiwai K, et al. Inhibition of hepatic mixed-function oxidase enzymes in mice by acute and chronic treatment with selenium. J Pharmacobiodyn 1992;15:377-85. PubMed
  15. Lippmann SM, Klein EA, Goodman PJ, et al. Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the selenium and vitamin E cancer prevention trial (SELECT). JAMA 2009;301:39-51. DOI
  16. Reid SM, Middleton P, Cossich MC, Crowther CA. Interventions for clinical and subclinical hypothyroidism in pregnancy. Cochrane Database Syst Rev 2010;(7):CD007752. PubMed
  17. Vinceti, M., Wei, E. T., Malagoli, C., Bergomi, M., and Vivoli, G. Adverse health effects of selenium in humans. Rev.Environ.Health 2001;16(4):233-251. PubMed
  18. Abrams, C. K., Siram, S. M., Galsim, C., Johnson-Hamilton, H., Munford, F. L., and Mezghebe, H. Selenium deficiency in long-term total parenteral nutrition. Nutr Clin Pract 1992;7(4):175-178. PubMed
  19. Spiller, H. A. and Pfiefer, E. Two fatal cases of selenium toxicity. Forensic Sci Int 8-24-2007;171(1):67-72. PubMed
  20. Negro, R., Greco, G., Mangieri, T., Pezzarossa, A., Dazzi, D., and Hassan, H. The influence of selenium supplementation on postpartum thyroid status in pregnant women with thyroid peroxidase autoantibodies. J Clin Endocrinol.Metab 2007;92(4):1263-1268. PubMed
  21. Alexander, J. Selenium. Novartis.Found.Symp 2007;282:143-149.
  22. Salonen, J. T., Salonen, R., Seppanen, K., Rinta-Kiikka, S., Kuukka, M., Korpela, H., Alfthan, G., Kantola, M., and Schalch, W. Effects of antioxidant supplementation on platelet function: a randomized pair-matched, placebo-controlled, double-blind trial
  23. Kupka, R., Mugusi, F., Aboud, S., Msamanga, G. I., Finkelstein, J. L., Spiegelman, D., and Fawzi, W. W. Randomized, double-blind, placebo-controlled trial of selenium supplements among HIV-infected pregnant women in Tanzania: effects on maternal and chil
  24. Kamble, P., Mohsin, N., Jha, A., Date, A., Upadhaya, A., Mohammad, E., Khalil, M., Pakkyara, A., and Budruddin, M. Selenium intoxication with selenite broth resulting in acute renal failure and severe gastritis. Saudi.J Kidney Dis.Transpl. 2009;20(1):106
  25. Peretz, A., Neve, J., Desmedt, J., Duchateau, J., Dramaix, M., and Famaey, J. P. Lymphocyte response is enhanced by supplementation of elderly subjects with selenium-enriched yeast. Am.J Clin.Nutr. 1991;53(5):1323-1328. PubMed
  26. Kumpulainen, J., Salmenpera, L., Siimes, M. A., Koivistoinen, P., and Perheentupa, J. Selenium status of exclusively breast-fed infants as influenced by maternal organic or inorganic selenium supplementation. Am.J Clin.Nutr. 1985;42(5):829-835. PubMed
  27. Han, L. and Zhou, S. M. Selenium supplement in the prevention of pregnancy induced hypertension. Chin Med J (Engl) 1994;107(11):870-871.
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Lithium 26 references
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See these in context on the Lithium monograph →

Lemon 2 references
  1. Ruggenenti P, Caruso MR, Cortinovis M, et al. Fresh lemon juice supplementation for the prevention of recurrent stones in calcium oxalate nephrolithiasis: A pragmatic, prospective, randomised, open, blinded endpoint (PROBE) trial. EClinicalMedicine 2021;4 PubMed
  2. Umemura K, Katada Y, Nakagawa S, et al. Improved absorption of itraconazole tablet by co-administration with lemon beverages in a lung transplant recipient: A case report. J Infect Chemother 2022;28(8):1203-1207. PubMed

See these in context on the Lemon 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.

© 2021 Therapeutic Research Center, LLC

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