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

Shade Factor Ingredients & Drug Interactions

by Life Extension

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

First and foremost: checking Shade Factor 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

Shade Factor is a dietary supplement by Life Extension with 4 active ingredients. Its ingredients are commonly taken for high cholesterol, vitamin b3 deficiency (pellagra), heart health support.Based on those ingredients, 1,267 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Niacin, Polypodium leucotomos extract, Red Orange Complex. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Shade Factor by Life Extension

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HelloPharmacist Scorecard of Shade Factor by Life Extension

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 Sep 10, 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 4 of its 4 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Shade Factor contains 4 active ingredients. Niacin, also called vitamin B3, is a water-soluble B vitamin used to address niacin deficiency and to support cholesterol and lipid metabolism.

Vitamin C is an antioxidant vitamin that your body needs for immune function and collagen formation. Red orange complex is a fruit extract that contains natural compounds from red oranges.

Polypodium leucotomos extract is derived from a type of fern and is used in some skin-health formulations. The product also contains inactive ingredients—vegetable cellulose, maltodextrin, microcrystalline cellulose, silica, and stearic acid—which serve as capsule material and fillers.

Does it work?

Not established
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
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use.

Why this rating?
  • The label markets this product for: sun protection and skin health support.
  • We looked for evidence on: Aging skin, Atopic dermatitis (eczema), photoaging, sun sensitivity, melasma.
  • The closest evidence on file: Vitamin C is rated "Insufficient Reliable Evidence To Rate" for Aging skin (Natural Medicines).
  • Also on file: Vitamin C is rated "Insufficient Reliable Evidence To Rate" for Melasma.
  • Also on file: Polypodium Leucotomos is rated "Insufficient Reliable Evidence To Rate" for Atopic dermatitis (eczema), Melasma.

Evidence for this product's effectiveness depends on the condition. Niacin is likely effective for niacin deficiency (pellagra) and possibly effective for managing cholesterol problems in people with HIV/AIDS-related high lipids and for metabolic syndrome.

Vitamin C is effective for vitamin C deficiency and possibly effective for anemia of chronic disease, cataracts, atrial fibrillation, and exercise-triggered respiratory infections. The red orange complex and Polypodium leucotomos extract have insufficient evidence to rate them for their proposed uses—the data we hold does not establish their effectiveness for the conditions listed on the label.

The evidence, ingredient by ingredient Niacin Vitamin C Sweet Orange Polypodium Leucotomos

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 4 of the 4 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 4 of 4.
  • General safety write-ups exist for 4 of 4.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Niacin at normal food levels and standard prescription doses under a doctor's supervision is generally well tolerated. At higher supplemental doses, it commonly causes flushing (up to 70% of people may experience this), gastrointestinal upset like nausea and heartburn, and can raise liver enzymes; rare serious effects include liver problems, muscle damage, low platelet counts, and vision changes.

High-dose niacin should be avoided in pregnancy and breastfeeding unless prescribed by a doctor. Vitamin C is well tolerated at normal dietary and supplement doses; very high doses can cause abdominal cramps, diarrhea, nausea, headache, and kidney stones (especially in those prone to them), and adverse effects become more likely above 2 grams daily.

Normal vitamin C from food and prenatal vitamins is fine in pregnancy and lactation, though high-dose supplements are not recommended without medical advice. Red orange fruit and juice are safe for most people; concentrated forms have less safety data.

Polypodium leucotomos is generally well tolerated in short-term studies, but long-term safety is not well established and there is not enough safety data to recommend it during pregnancy or breastfeeding.

Side effects, ingredient by ingredient Niacin Vitamin C Sweet Orange Polypodium Leucotomos

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?
  • 4 of the 4 matched ingredients can interact with medications — Sweet Orange, Niacin, Vitamin C, Polypodium Leucotomos.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; cancer treatments; diabetes medications.
  • For scale: 1,268 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 Shade Factor, double-check with your doctor or pharmacist if you take organic anion-transporting polypeptide substrates (OATP), pravastatin, ivermectin, celiprolol, or other P-glycoprotein substrates—these carry Major-severity interactions with the red orange complex. Also flag blood pressure drugs, blood thinners (anticoagulants) or antiplatelet agents, diabetes medications, statins, gout drugs, liver-damaging medications, bile acid binders, high-dose vitamin C with warfarin or estrogen therapy, and any drugs metabolized by CYP3A4—these carry Moderate or Minor interactions with one or more of the product's ingredients.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Major medication interactions have been identified, and safety information is well characterized.

Shade Factor may be worth considering if you're looking to address niacin deficiency or support cholesterol metabolism, though the red orange and fern extract components lack established evidence for their marketed purposes. If you take any blood pressure medications, diabetes drugs, blood thinners, cholesterol-lowering statins, hormone therapy, or gout medications, or if you're on chemotherapy or any heart medications, you'll need to check with your doctor or pharmacist before starting this product.

Pregnant or breastfeeding individuals should talk with their healthcare provider first, especially because polypodium leucotomos lacks adequate safety data for those situations.

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

Assessment coverage: 4 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Aug 23, 2020.

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 Shade Factor, straight from the product label.

Brand Life Extension
Barcode (UPC) 737870193814
Net contents 120 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD Aug 23, 2020
DSLD ID 232572
Product type Botanical With Nutrients
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Shade Factor by Life Extension, 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
60
UPC/BARCODE
737870193814
IngredientAmount% DV
Niacin500 mg NE3125%
Vitamin C5.5 mg6%
Red Orange Complex100 mg--
Polypodium leucotomos extract240 mg--

Other ingredients: Vegetable Cellulose, Maltodextrin, Microcrystalline Cellulose, Silica, 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.
Suggested/Recommended/Usage/Directions

Read the entire label and follow the directions carefully prior to use. Directions: Take two (2) capsules twice daily, with or without food, or as recommended by a healthcare practitioner.

Precautions

Caution: This product is not a substitute for topical sunscreens. Gastric disturbances may occur. Consult with your healthcare provider before taking this product if you have gout or liver disease.

Warnings: Keep out of reach of children.

Do not exceed recommended dose. Do not purchase if outer seal is broken or damaged.

When using nutritional supplements, please consult with your physician if you are undergoing treatment for a medical condition or if you are pregnant or lactating.

To report a serious adverse event or obtain product information, contact 1-866-280-2852.

Storage

Store tightly closed in a cool, dry place.

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Seals/Symbols

Non GMO LE Certified

Formulation

Non GMO LE Certified

Oral support for skin health

FDA Statement of Identity

Dietary Supplement

Brand IP Statement(s)

Red Orange Complex is a registered trademark of Bionap S.r.l.

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

See for yourself

Shade Factor by Life Extension label

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

Shade Factor 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 Shade Factor by Life Extension

These are the 4 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Vegetarian Capsule(s) Dosage formCapsule Servings per container60 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.

Niacin

Interacts with
727 drugs
500 mg NE per serving Form: Niacinamide

Niacin (vitamin B3) is an essential nutrient your body needs for energy and metabolism, and deficiency is uncommon in most developed countries. Prescr...

Niacin monograph & interactions

Vitamin C

Interacts with
207 drugs
5.5 mg per serving Form: Red Orange Complex

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

Red Orange Complex

Interacts with
246 drugs
100 mg per serving

Sweet orange is a common citrus fruit that is a good source of vitamin C, fiber, and antioxidants, and is enjoyed as a food worldwide. Its peel and es...

Red Orange Complex monograph & interactions

Polypodium leucotomos extract

Interacts with
643 drugs
240 mg per serving

Polypodium leucotomos is a fern extract taken by mouth, mostly studied as an add-on to (not a replacement for) sunscreen and for certain light-trigger...

Polypodium leucotomos extract monograph & interactions

Other (inactive) ingredients: Vegetable Cellulose, Maltodextrin, Microcrystalline Cellulose, Silica, Stearic Acid. These complete the product’s ingredient list but are not active constituents.

Interaction report

Shade Factor by Life Extension Drug Interactions

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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
1,267Drugs
48 Major 872 Moderate 347 Minor

Ingredients driving the most interactions

Niacin 727
Polypodium leucotomos extract 643
Red Orange Complex 246
Vitamin C 207

Individual Drug Interactions

The ingredients in Shade Factor interact with 1,267 drugs. Click any drug to see the details.

4 of the 4 ingredients in Shade Factor interact with drugs. Each result below shows which ingredient is responsible. Niacin Polypodium leucotomos extract Red Orange Complex Vitamin C

Each ingredient & the kinds of drugs it affects

For each ingredient in Shade Factor 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.

Niacin15 drug types · 727 drugs

Alcohol (Ethanol)

Concomitant use of alcohol and niacin might increase the risk of flushing and hepatotoxicity.
Alcohol can exacerbate the flushing and pruritus associated with niacin. Large doses of niacin might also exacerbate liver dysfunction associated with chronic alcohol use. A case report describes delirium and lactic acidosis in a patient taking niacin 3 grams daily who ingested 1 liter of wine. Advise patients to avoid large amounts of alcohol while taking niacin.

Likelihood Probable Evidence D
Allopurinol (Zyloprim)

Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as allopurinol.
Large doses of niacin can reduce urinary excretion of uric acid, potentially resulting in hyperuricemia. Doses of uricosurics such as allopurinol might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.

Likelihood Probable Evidence C
Anticoagulant/Antiplatelet Drugs

Theoretically, niacin may have additive effects when used with anticoagulant or antiplatelet drugs.
Several cases of clotting factor synthesis deficiency and coagulopathy have been reported in patients taking sustained-release niacin. Also, thrombocytopenia has been reported in patients treated with niacin or niacin plus lovastatin.

Likelihood Possible Evidence D
Antidiabetes Drugs

Niacin can increase blood glucose levels and may diminish the effects of antidiabetes drugs.
Niacin impairs glucose tolerance in a dose-dependent manner, probably by causing or aggravating insulin resistance and increasing hepatic production of glucose. In diabetes patients, niacin 4.5 grams daily for 5 weeks can increase plasma glucose by an average of 16% and glycated hemoglobin (HbA1c) by 21%. However, lower doses of 1.5 grams daily or less appear to have minimal effects on blood glucose. In some patients, glucose levels increase when niacin is started, but then return to baseline when a stable dose is reached. Up to 35% of patients with diabetes may need adjustments in hypoglycemic therapy when niacin is added.

Likelihood Probable Evidence B
Antihypertensive Drugs

Theoretically, niacin may increase the risk of hypotension when used with antihypertensive drugs.
The vasodilating effects of niacin can cause hypotension. Furthermore, some clinical evidence suggests that a one-hour infusion of niacin can reduce systolic, diastolic, and mean blood pressure in hypertensive patients. This effect is not observed in normotensive patients.

Likelihood Possible Evidence B
Bile Acid Sequestrants

Bile acid sequestrants can bind niacin and decrease absorption. Separate administration by 4-6 hours to avoid an interaction.
In vitro studies show that colestipol (Colestid) binds about 98% of available niacin and cholestyramine (Questran) binds 10% to 30%.

Likelihood Possible Evidence D
Gemfibrozil (Lopid)

Theoretically, concomitant use of niacin and gemfibrozil might increase the risk of myopathy in some patients.
A case of myopathy from concomitant use of niacin and gemfibrozil has been reported. Niacin alone has also been associated with cases of myopathy. Using gemfibrozil with niacin might further increase the risk of developing myopathy.

Likelihood Possible Evidence D
Hepatotoxic Drugs

Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Niacin has been associated with cases of liver toxicity, especially when used in pharmacologic doses. Sustained-release niacin preparations appear to be associated with a higher risk of hepatotoxicity than immediate-release niacin.

Likelihood Possible Evidence D
Hmg-Coa Reductase Inhibitors ("Statins")

Theoretically, concomitant use of niacin and statins might increase the risk of myopathy and rhabdomyolysis in some patients.
Some case reports have raised concerns that niacin might increase the risk of myopathy and rhabdomyolysis when combined with statins. However, a significantly increased risk of myopathy has not been demonstrated in clinical trials, including those using an FDA-approved combination of lovastatin and niacin (Advicor).

Likelihood Possible Evidence D
Probenecid (Benemid)

Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as probenecid.
Large doses of niacin reduce urinary excretion of uric acid, potentially causing hyperuricemia. Doses of uricosurics such as probenecid might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.

Likelihood Probable Evidence C
Sulfinpyrazone (Anturane)

Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as sulfinpyrazone.
Large doses of niacin reduce urinary excretion of uric acid, potentially causing hyperuricemia. Doses of uricosurics such as sulfinpyrazone might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.

Likelihood Probable Evidence C
Thyroid Hormone

Theoretically, niacin might antagonize the therapeutic effects of thyroid hormones.
Clinical research and case reports suggests that taking niacin can reduce serum levels of thyroxine-binding globulin by up to 25% and moderately reduce levels of thyroxine (T4). Patients taking thyroid hormone for hypothyroidism might need dose adjustments when using niacin.

Likelihood Probable Evidence D
Transdermal Nicotine (Nicoderm)

Theoretically, concomitant use of niacin and transdermal nicotine might increase the risk of flushing and dizziness.
Niacin and nicotine can both cause flushing and dizziness.

Likelihood Possible Evidence D
Warfarin (Coumadin)

There is limited evidence that niacin may increase the anticoagulant effects of warfarin.
In a case report, a patient on warfarin developed an elevated international normalized ratio (INR) of 3.9 after taking niacin for two weeks. The patient's INR was previously stable, ranging between 2 and 3 in recent months, and no other medication changes were identified. The elevated INR returned to therapeutic range within 4 days following the discontinuation of niacin.

Likelihood Possible Evidence D
Aspirin

Large doses of aspirin might alter the clearance of niacin.
Aspirin is often used with niacin to reduce niacin-induced flushing. Doses of 80-975 mg aspirin have been used, but 325 mg appears to be optimal. Aspirin also seems to reduce the clearance of niacin by competing for glycine conjugation. Taking aspirin 1 gram seems to reduce niacin clearance by 45%. This is probably a dose-related effect and not clinically significant with the more common aspirin dose of 325 mg.

Likelihood Likely Evidence B
Niacin full monograph & interactions

Polypodium leucotomos extract1 drug type · 643 drugs

Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, Polypodium leucotomos might increase levels of drugs metabolized by CYP3A4.
In vitro and animal research suggests that Polypodium leucotomos can decrease the metabolism of midazolam by a mechanism possibly related to the inhibition of CYP3A4. However, a small study in humans suggests that taking Polypodium leucotomos with midazolam does not affect the metabolism of midazolam.

Likelihood Unlikely Evidence B
Polypodium leucotomos extract full monograph & interactions

Red Orange Complex7 drug types · 246 drugs

Celiprolol (Celicard)

Consuming sweet orange with celiprolol can decrease oral absorption of celiprolol.
A pharmacokinetic study in healthy volunteers shows that celiprolol levels, after a single dose of 100 mg, are decreased by up to 90% in people who drink sweet orange juice 200 mL three times daily. It's not known if lower consumption of sweet orange juice will have the same effect. Theoretically, this occurs due to short-term inhibition of organic anion transporting polypeptide (OATP). Recommend separating drug administration and consumption of sweet orange by at least 4 hours.

Likelihood Likely Evidence B
Ivermectin (Stromectol, Others)

Consuming sweet orange juice with ivermectin can decrease the oral absorption of ivermectin.
A pharmacokinetic study in healthy volunteers shows that taking ivermectin orally with sweet orange juice 750 mL over 4 hours reduces the bioavailability of ivermectin. This effect does not seem to be related to effects on P-glycoprotein. The effect on ivermectin is more pronounced in males compared to females.

Likelihood Likely Evidence B
Organic Anion-Transporting Polypeptide Substrates (Oatp)

Consuming sweet orange juice can decrease oral absorption of OATP substrates. Separate administration by at least 4 hours.
Clinical research shows that consuming sweet orange juice inhibits OATP, which reduces bioavailability of oral drugs that are substrates of OATP. For example, sweet orange juice decreases bioavailability of fexofenadine, a substrate of OATP, by about 72% and of celiprolol, another OATP substrate, by up to 90%. Since sweet orange juice seems to affect OATP for a short time, recommend separating drug administration and consumption of sweet orange juice by at least 4 hours.

Likelihood Likely Evidence B
Pravastatin (Pravachol)

Consuming sweet orange juice with pravastatin can increase the absorption of pravastatin.
A small pharmacokinetic study in healthy volunteers shows that consuming sweet orange juice 800 mL over 3 hours, including before, during, and after taking pravastatin 10 mg, increases pravastatin levels by about 149%, without affecting pravastatin elimination. Theoretically this effect might be due to modulation of organic anion transporting polypeptides (OATPs) by sweet orange juice. Sweet orange juice does not seem to affect simvastatin levels, but it is not known if sweet orange affects any of the other statins.

Likelihood Likely Evidence B
Fexofenadine (Allegra)

Consuming sweet orange juice with fexofenadine can decrease oral absorption of fexofenadine.
Clinical research shows that coadministration of sweet orange juice 1200 mL decreases bioavailability of fexofenadine by about 72%. In an animal model, sweet orange juice decreased bioavailability of fexofenadine by 31%. Fexofenadine manufacturer data indicates that concomitant administration of sweet orange juice and fexofenadine results in larger wheal and flare sizes in research models. This suggests that sweet orange reduces the clinical response to fexofenadine. Theoretically, this occurs due to short-term inhibition of organic anion transporting polypeptide (OATP). Recommend separating drug administration and consumption of sweet orange by at least 4 hours.

Likelihood Likely Evidence B
P-Glycoprotein Substrates

Sweet orange juice seems to modulate P-glycoprotein (P-gp), which might affect the blood levels of P-gp substrates.
Animal and in vitro research suggest that orange juice extract inhibits drug efflux by P-gp, increasing absorption and levels of P-gp substrates. In contrast, pharmacokinetic research in humans shows that drinking large amounts of sweet orange juice decreases absorption and levels of the P-gp substrate celiprolol. This suggests that orange juice actually induces drug efflux by P-gp or affects drug levels by another mechanism such as inhibiting the gut drug transporter called organic anion transporting polypeptide (OATP). Until more is known, sweet orange juice should be used cautiously in people taking P-gp substrates.

Likelihood Possible Evidence B
Quinolone Antibiotics

Calcium-fortified sweet orange juice might reduce quinolone absorption.
Calcium binds to quinolones in the gut. Theoretically, the calcium in certain fortified orange juices can also bind to quinolone antibiotics and reduce their absorption and levels.

Likelihood Possible Evidence D
Red Orange Complex 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
The maker

Brand information

Manufacturer and brand details for Shade Factor, from the product label.

Life Extension

See all Life Extension products
Name
Quality Supplements and Vitamins, Inc.
City
Ft. Lauderdale
State
FL
ZipCode
33309
Phone Number
1-866-280-2852
Web Address
LifeExtension.com
Pharmacist Counseling Corner

Shade Factor by Life Extension: Common Questions

Does Shade Factor by Life Extension interact with any medications?
Yes. Based on its ingredients, Shade Factor has a known interaction with 1,267 medications, including 48 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Shade Factor contains 4 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 really help with sun protection?
Niacin is established for niacin deficiency and possibly helpful for cholesterol issues. The red orange complex and Polypodium leucotomos extract, which make up much of what's in this product, have insufficient evidence to establish whether they work for their proposed purposes according to our data.
What's the most common side effect of niacin in Shade Factor?
Flushing—a warm, tingling, burning sensation in the face and upper body—is the most common effect, happening in up to 70% of people who take niacin. Gastrointestinal complaints like nausea, heartburn, and diarrhea are also frequent. These often improve within a couple of weeks or can be reduced by taking it with food.
Can I take this while pregnant?
Niacin and vitamin C at normal dietary amounts are considered safe in pregnancy, but high-dose niacin should be avoided unless prescribed by your doctor. There is not enough safety data on Polypodium leucotomos in pregnancy, so it's safer to avoid it. Talk with your doctor or pharmacist about whether this product is right for you before taking it.
Why does the label mention separating this from certain medications by 4 hours?
The red orange complex can bind to some medications in your gut and reduce how much your body absorbs. Separating them by 4 hours gives your body time to absorb the medication before the supplement interferes. Your doctor or pharmacist can tell you which of your specific drugs need this separation.
Is it safe to take this if I'm on a statin for cholesterol?
That depends on which statin. The red orange complex can raise levels of pravastatin significantly, which could increase the risk of side effects. For other statins, niacin itself may theoretically increase the risk of muscle damage. Check with your doctor or pharmacist before combining any statin with this product.
Can high doses of the vitamin C in this product thin my blood?
Very high doses of vitamin C (16 grams daily or more) may reduce how well warfarin and other blood thinners work by reducing their absorption. The amount of vitamin C in this supplement is unlikely to cause that effect, but if you take warfarin, check with your pharmacist before starting any new supplement.

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.

Shade Factor label
Go deeper

The Full Monographs Behind Shade Factor’s Ingredients

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

Herb & supplement monograph

Niacin

Interacts with 727 drugs

Niacin (vitamin B3) is an essential nutrient your body needs for energy and metabolism, and deficiency is uncommon in most developed countries. Prescription-strength niacin has been used to...

Read the full Niacin 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

Sweet Orange

Interacts with 246 drugs

Sweet orange is a common citrus fruit that is a good source of vitamin C, fiber, and antioxidants, and is enjoyed as a food worldwide. Its peel and essential oil are used in aromatherapy and...

Read the full Sweet Orange monograph → Herb & supplement monograph

Polypodium Leucotomos

Interacts with 643 drugs

Polypodium leucotomos is a fern extract taken by mouth, mostly studied as an add-on to (not a replacement for) sunscreen and for certain light-triggered skin conditions. Some early research...

Read the full Polypodium Leucotomos monograph →
Sources

Sources & How We Checked

Shade Factor'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 136 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.

Niacin 66 references
  1. Garg R, Malinow MR, Pettinger M, et al. Niacin treatment increases plasma homocysteine levels. Am Heart J 1999;138:1082-7.
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  4. Guyton JR, Blazing MA, Hagar J, et al. Extended-release niacin vs gemfibrozil for the treatment of low levels of high-density lipoprotein cholesterol. Niaspan-Gemfibrozil Study Group. Arch Intern Med 2000;160:1177-84. PubMed
  5. Gibbons LW, Gonzalez V, Gordon N, Grundy S. The prevalence of side effects with regular and sustained-release nicotinic acid. Am J Med 1995;99:378-85. PubMed
  6. Whelan AM, Price SO, Fowler SF, Hainer BL. The effect of aspirin on niacin-induced cutaneous reactions. J Fam Pract 1992;34:165-8.
  7. Jungnickel PW, Maloley PA, Vander Tuin EL, et al. Effect of two aspirin pretreatment regimens on niacin-induced cutaneous reactions. J Gen Intern Med 1997;12:591-6. PubMed
  8. Capuzzi DM, Guyton JR, Morgan JM, et al. Efficacy and safety of an extended-release niacin (Niaspan): a long-term study. Am J Cardiol 1998;82:74-81;disc. 85U-6U. PubMed
  9. Gray DR, Morgan T, Chretien SD, Kashyap ML. Efficacy and safety of controlled-release niacin in dyslipoproteinemic veterans. Ann Intern Med 1994;121:252-8. PubMed
  10. McKenney JM, Proctor JD, Harris S, Chinchili VM. A comparison of the efficacy and toxic effects of sustained- vs immediate-release niacin in hypercholesterolemic patients. JAMA 1994;271:672-7. DOI
  11. Knopp RH, Alagona P, Davidson M, et al. Equivalent efficacy of a time-release form of niacin (Niaspan) given once-a-night versus plain niacin in the management of hyperlipidemia. Metabolism 1998;47:1097-104. PubMed
  12. Knopp RH. Clinical profiles of plain versus sustained-release niacin (Niaspan) and the physiologic rationale for nighttime dosing. Am J Cardiol 1998;82:24U-28U;discussion 39U-41U. PubMed
  13. Garg A, Grundy SM. Nicotinic acid as therapy for dyslipidemia in non-insulin-dependent diabetes mellitus. JAMA 1990;264:723-6. DOI
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  16. Vega GL, Grundy SM. Lipoprotein responses to treatment with lovastatin, gemfibrozil, and nicotinic acid in normolipidemic patients with hypoalphalipoproteinemia. Arch Intern Med 1994;154:73-82. DOI
  17. Guyton JR, Goldberg AC, Kreisberg RA, et al. Effectiveness of once-nightly dosing of extended-release niacin alone and in combination for hypercholesterolemia. Am J Cardiol 1998;82:737-43.
  18. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
  19. 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
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  23. Schwartz ML. Severe reversible hyperglycemia as a consequence of niacin therapy. Arch Int Med 1993;153:2050-2. DOI
  24. Raising HDL and Niacin Use. Pharmacist's Letter/Prescriber's Letter 2004;20(5):200504.
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  37. Dunn RT, Ford MA, Rindone JP, Kwiecinski FA. Low-Dose Aspirin and Ibuprofen Reduce the Cutaneous Reactions Following Niacin Administration. Am J Ther. 1995;2(7):478-480. PubMed
  38. Cashin-Hemphill L, Spencer CA, Nicoloff JT, et al. Alterations in serum thyroid hormonal indices with colestipol-niacin therapy. Ann Intern Med. 1987;107(3):324-9. PubMed
  39. Drinka PJ. Alterations in thyroid and hepatic function tests associated with preparations of sustained-release niacin. Mayo Clin Proc. 1992;67(12):1206. PubMed
  40. Shakir KM, Kroll S, Aprill BS, Drake AJ 3rd, Eisold JF. Nicotinic acid decreases serum thyroid hormone levels while maintaining a euthyroid state. Mayo Clin Proc. 1995;70(6):556-8. PubMed
  41. Etchason JA, Miller TD, Squires RW, et al. Niacin-induced hepatitis: a potential side effect with low-dose time-release niacin. Mayo Clin Proc. 1991;66(1):23-8. PubMed
  42. Henkin Y, Johnson KC, Segrest JP. Rechallenge with crystalline niacin after drug-induced hepatitis from sustained-release niacin. JAMA. 1990;264(2):241-3. DOI
  43. Henkin Y, Oberman A, Hurst DC, Segrest JP. Niacin revisited: clinical observations on an important but underutilized drug. Am J Med. 1991;91(3):239-46. PubMed
  44. Brown BG, Bardsley J, Poulin D, et al. Moderate dose, three-drug therapy with niacin, lovastatin, and colestipol to reduce low-density lipoprotein cholesterol <100 mg/dl in patients with hyperlipidemia and coronary artery disease. Am J Cardiol. 1997;80(2)
  45. Goldberg A, Alagona P Jr, Capuzzi DM, et al. Multiple-dose efficacy and safety of an extended-release form of niacin in the management of hyperlipidemia. Am J Cardiol. 2000;85(9):1100-5. PubMed
  46. Aronov DM, Keenan JM, Akhmedzhanov NM, et al. Clinical trial of wax-matrix sustained-release niacin in a Russian population with hypercholesterolemia. Arch Fam Med. 1996;5(10):567-75. PubMed
  47. Morgan JM, Capuzzi DM, Guyton JR, et al. Treatment Effect of Niaspan, a Controlled-release Niacin, in Patients With Hypercholesterolemia: A Placebo-controlled Trial. J Cardiovasc Pharmacol Ther. 1996;1(3):195-202. PubMed
  48. Andersson RG, Aberg G, Brattsand R, Ericsson E, Lundholm L. Studies on the mechanism of flush induced by nicotinic acid. Acta Pharmacol Toxicol (Copenh). 1977 Jul;41(1):1-10. PubMed
  49. Brown WV. Niacin for lipid disorders. Indications, effectiveness, and safety. Postgrad Med. 1995 Aug;98(2):185-9, 192-3. PubMed
  50. O'REILLY PO, CALLBECK MJ, HOFFER A. Sustained-release nicotinic acid (nicospan); effect on (1) cholesterol levels and (2) leukocytes. Can Med Assoc J. 1959;80(5):359-62.
  51. Gharavi AG, Diamond JA, Smith DA, Phillips RA. Niacin-induced myopathy. Am J Cardiol. 1994;74(8):841-2. PubMed
  52. Litin SC, Anderson CF. Nicotinic acid-associated myopathy: a report of three cases. Am J Med. 1989;86(4):481-3. PubMed
  53. Fraunfelder FW, Fraunfelder FT, Illingworth DR. Adverse ocular effects associated with niacin therapy. Br J Ophthalmol 1995;79:54-56. PubMed
  54. Ali EH, McJunkin B, Jubelirer S, Hood W. Niacin induced coagulopathy as a manifestation of occult liver injury. W V Med J. 2013 Jan-Feb;109(1):12-4
  55. Aramwit P, Srisawadwong R, Supasyndh O. Effectiveness and safety of extended-release nicotinic acid for reducing serum phosphorus in hemodialysis patients. J Nephrol. 2012 May-Jun;25(3):354-62. PubMed
  56. Bassan M. A case for immediate-release niacin. Heart Lung. 2012 Jan-Feb;41(1):95-8. PubMed
  57. Davidson MH, Rooney M, Pollock E, Drucker J, Choy Y. Effect of colesevelam and niacin on low-density lipoprotein cholesterol and glycemic control in subjects with dyslipidemia and impaired fasting glucose. J Clin Lipidol. 2013 Sep-Oct;7(5):423-32. PubMed
  58. Guyton JR, Fazio S, Adewale AJ, Jensen E, Tomassini JE, Shah A, Tershakovec AM. Effect of extended-release niacin on new-onset diabetes among hyperlipidemic patients treated with ezetimibe/simvastatin in a randomized controlled trial. Diabetes Care. 2012 PubMed
  59. Loebl T, Raskin S. A novel case report: acute manic psychotic episode after treatment with niacin. J Neuropsychiatry Clin Neurosci. 2013 Fall;25(4):E14. PubMed
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  61. Goldie C, Taylor AJ, Nguyen P, McCoy C, Zhao XQ, Preiss D. Niacin therapy and the risk of new-onset diabetes: a meta-analysis of randomized controlled trials. Heart. 2016 Feb;102(3):198-203.
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  64. Song S, Lee CJ, Oh J, Park S, Kang SM, Lee SH. Effect of Niacin on Carotid Atherosclerosis in Patients at Low-Density Lipoprotein-Cholesterol Goal but High Lipoprotein (a) Level: a 2-Year Follow-Up Study. J Lipid Atheroscler. 2019;8(1):58-66. PubMed
  65. Kimura H, Umemori Y, Yuki D. Anaphylactic shock-like symptoms due to niacin overdose: A case report. J Dermatol 2022;49(8):e287-e288. PubMed
  66. Nawaz N, Mistretta T, Karime C, Lewis J, Wolf E. Cholestatic Drug-Induced Liver Injury in a Patient Taking High-Dose Niacin for Hyperlipidemia. J Investig Med High Impact Case Rep 2024;12:23247096231224349. PubMed

See these in context on the Niacin monograph →

Vitamin C 51 references
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See these in context on the Vitamin C monograph →

Sweet Orange 17 references
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  7. Lilja JJ, Juntti-Patinen L, Neuvonen PJ. Orange juice substantially reduces the bioavailability of the beta-adrenergic-blocking agent celiprolol. Clin Pharmacol Ther 2004;75:184-90.
  8. Tian R, Koyabu N, Takanaga H, et al. Effects of grapefruit juice and orange juice on the intestinal efflux of P-glycoprotein substrates. Pharm Res 2002;19:802-9. PubMed
  9. Vanapalli SR, Chen Y, Ellingrod VL, et al. Orange juice decreases the oral bioavailability of ivermectin in health volunteers. Clin Pharmacol Ther 2003;73 (Abstract PDII-A-10):P94.
  10. Huang SM, Lesko LJ. Drug-drug, drug-dietary supplement, and drug-citrus fruit and other food interactions: what have we learned? J Clin Pharmacol 2004;44:559-69. PubMed
  11. Koitabashi Y, Kumai T, Matsumoto N, et al. Orange juice increased the bioavailability of pravastatin, 3-hydroxy-3-methylglutaryl CoA reductase inhibitor, in rats and healthy human subjects. Life Sci 2006;78:2852-9. PubMed
  12. Takanaga H, Ohnishi A, Yamada S, et al. Polymethoxylated flavones in orange juice are inhibitors of P-glycoprotein but not cytochrome P450 3A4. J Pharmacol Exp Ther 2000;293:230-6. DOI
  13. Greenblatt DJ. Analysis of drug interactions involving fruit beverages and organic anion-transporting polypeptides. J Clin Pharmacol 2009;49:1403-7. PubMed
  14. Bailey DG. Fruit juice inhibition of uptake transport: a new type of food-drug interaction. Br J Clin Pharmacol 2010;70:645-55. PubMed
  15. Kamath AV, Yao M, Zhang Y, Chong S. Effect of fruit juices on the oral bioavailability of fexofenadine in rats. J Pharm Sci 2005;94:233-9. PubMed
  16. Kays MB, Overholser BR, Mueller BA, et al. Effects of sevelamer hydrochloride and calcium acetate on the oral bioavailability of ciprofloxacin. Am J Kidney Dis. 2003;42(6):1253-9. PubMed
  17. Neuhofel, A. L., Wilton, J. H., Victory, J. M., Hejmanowsk, L. G., and Amsden, G. W. Lack of bioequivalence of ciprofloxacin when administered with calcium-fortified orange juice: a new twist on an old interaction. J Clin Pharmacol. 2002;42(4):461-466. DOI

See these in context on the Sweet Orange monograph →

Polypodium Leucotomos 2 references
  1. Goh CL, Chuah SY, Tien S, Thng G, Vitale MA, Delgado-Rubin A. Double-blind, placebo-controlled trial to evaluate the effectiveness of Polypodium leucotomos extract in the treatment of melasma in Asian skin: a pilot study. J Clin Aesthet Dermatol 2018;11(3
  2. Shinya K, Nishimura Y, Ryu K, et al. Short-term administration of Polypodium leucotomos extract does not inhibit CYP3A4-mediated metabolism of midazolam in healthy subjects: an open-label, two-period, fixed-sequence study. Int J Dermatol 2022.

See these in context on the Polypodium Leucotomos monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

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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