Glutathione, Cysteine & C Ingredients & Drug Interactions
What is this page for?
First and foremost: checking Glutathione, Cysteine & C 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
Glutathione, Cysteine & C is a dietary supplement by Life Extension with 3 active ingredients. Its ingredients are commonly taken for antioxidant support, skin and hair health, liver support.Based on those ingredients, 293 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Vitamin C, L-Cysteine Hydrochloride. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against Glutathione, Cysteine & C by Life Extension
Ask about any prescription or over-the-counter medication and we check it for interactions with Glutathione, Cysteine & C by Life Extension — and tell you which ingredient is responsible.
AI summaries are generated from our interaction database for education only — always confirm with your pharmacist. How we use AI
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HelloPharmacist Scorecard of Glutathione, Cysteine & C 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.
What’s inside
Full disclosure
This product contains three active ingredients: L-cysteine hydrochloride (an amino acid), Setria glutathione (a compound your body makes naturally), and vitamin C (ascorbic acid). The capsule also holds inactive ingredients — cellulose, microcrystalline cellulose, stearic acid, stearate, and silica — which are fillers and binders.
Does it work?
Strong evidence
Evidence for these ingredients is mixed. Vitamin C is effective for vitamin C deficiency and possibly effective for anemia of chronic disease, atrial fibrillation, cataracts, and exercise-induced respiratory infections.
Glutathione is possibly effective for cisplatin-induced nerve damage (a chemotherapy side effect), though evidence for other uses like nonalcoholic fatty liver disease and Alzheimer's disease isn't yet established. For L-cysteine, the evidence we hold doesn't support claims for hair loss, leg ulcers, hangover, stroke, or gastritis — the data rates all of these as insufficient.
How safe is it?
Well-documented data
Vitamin C is generally well tolerated at normal dietary and supplement doses, though very high doses can cause abdominal cramps, heartburn, osmotic diarrhea, nausea, vomiting, and headache — especially above 2 grams daily. Kidney stones have been reported in people prone to them.
L-cysteine is generally well tolerated in food amounts, but safety data on supplement-level doses is limited, so avoid high-dose supplements unless your doctor advises otherwise. Glutathione appears well tolerated by mouth in the short term, though long-term safety isn't clear.
During pregnancy, vitamin C at normal amounts from food and prenatal vitamins is fine, but avoid high-dose supplements unless your doctor advises it. For glutathione, there isn't enough reliable safety information, so it's best avoided in pregnancy unless directed by your doctor.
Breastfeeding: avoid glutathione supplements due to insufficient safety data.
Meds to double-check
Moderate interaction found
Before taking this product, double-check with your pharmacist if you take antidiabetes drugs (L-cysteine may lower blood sugar), warfarin or other blood thinners, estrogens or oral contraceptives, levothyroxine or other thyroid drugs, indinavir or other HIV medications, fluphenazine or other antipsychotics, or chemotherapy drugs like alkylating agents or antitumor antibiotics. Also mention any aluminum-containing products you use.
High-dose vitamin C can change how these medications work.
The bottom line
Scorecard at a glanceFully disclosed formula with strong clinical evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.
This product might work for you if you're deficient in vitamin C or interested in glutathione for cisplatin-related side effects, but the evidence for other uses is thin. If you take antidiabetes medication, warfarin, birth control, thyroid medication, an HIV drug, an antipsychotic, or chemotherapy, talk to your pharmacist before starting — several interactions need checking at your specific dose.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 3 of 3 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated May 21, 2025.
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
General information
Key facts about Glutathione, Cysteine & C, straight from the product label.
| Brand | Life Extension |
|---|---|
| Barcode (UPC) | 737870154112 |
| Net contents | 100 Capsule(s) |
| Market status | On market |
| Date entered into DSLD | May 21, 2025 |
| DSLD ID | 328468 |
| Product type | Other Combinations |
| Supplement form | Capsule |
| Dietary claims / uses | Nutrient, All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years), Gluten Free |
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 Glutathione, Cysteine & C by Life Extension, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| L-Cysteine Hydrochloride | 200 mg | -- |
| Setria | 50 mg | -- |
| Vitamin C | 500 mg | 556% |
Other ingredients: Cellulose, Microcrystalline Cellulose, Stearic Acid, Stearate, Silica
Tap any ingredient to jump to its full detail below.
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
General Statements
Scan for product info
Precautions
Read the entire label and follow the directions carefully prior to use.
Warnings: Keep out of reach of children.
Do not exceed recommended dose. Do not purchase if outer seal is damaged.
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.
Suggested/Recommended/Usage/Directions
Directions: Take one (1) capsule one to three times daily on an empty stomach, or as recommended by a healthcare practitioner.
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.
Formulation
Gluten free Non GMO LE Certified
Seals/Symbols
Non GMO LE Certified
Formula
Amino Acids for immune support
FDA Statement of Identity
Dietary Supplement
Brand IP Statement(s)
Setria is a registered trademark of KYOWA HAKKO BIO CO., Ltd.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
Glutathione, Cysteine & C by Life Extension label
The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.
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)The Ingredients in Glutathione, Cysteine & C by Life Extension
These are the 3 active ingredients this product is made of. Select any to open its full monograph.
Serving size1 Capsule(s) Dosage formCapsule Servings per container100 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-Cysteine Hydrochloride
Interacts with86 drugs
L-cysteine is a sulfur-containing amino acid your body uses to make proteins and the antioxidant glutathione. Most people get enough from food, and su...
L-Cysteine Hydrochloride monograph & interactionsSetria
No knowninteractions
Glutathione is a powerful antioxidant your body makes naturally, and many people take it as a supplement hoping for skin, detox, or anti-aging benefit...
Setria monograph & interactionsVitamin C
Interacts with207 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 im...
Vitamin C monograph & interactionsOther (inactive) ingredients: Cellulose, Microcrystalline Cellulose, Stearic Acid, Stearate, Silica. These complete the product’s ingredient list but are not active constituents.
Glutathione, Cysteine & C by Life Extension Drug Interactions
HelloPharmacist Interaction Report
Life Extension's Glutathione, Cysteine & C contains three active ingredients, and the product does interact with a number of medications.
The most serious concern is vitamin C, which can affect blood levels or effectiveness of several drug types.
Read the full breakdown — every affected drug type, severity by severity
Vitamin C is a Moderate-severity concern with estrogens (including oral contraceptives and hormone replacement therapy) — it may raise estrogen blood levels by up to 55% in some cases. It also interacts Moderately with warfarin (a blood thinner) at high doses, potentially reducing how well the drug works.
Additionally, vitamin C can Moderately affect levothyroxine (thyroid medication), indinavir (an HIV drug), fluphenazine (an antipsychotic), and chemotherapy drugs including alkylating agents and antitumor antibiotics — either by changing drug levels or theoretically reducing their effectiveness.
Vitamin C also Moderately increases absorption of aluminum from aluminum-containing products. L-cysteine carries a Moderate interaction with antidiabetes drugs — animal research suggests it may lower blood sugar, which could raise the risk of low blood sugar episodes (hypoglycemia) when combined with diabetes medications.
Altogether, these interactions span 292 individual medications.
Glutathione (Setria) has no known interactions documented in our data. Check your exact medications with the search tool on this page before starting.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against Glutathione, Cysteine & C?
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 checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in Glutathione, Cysteine & C interact with 293 drugs. Click any drug to see the details.
2 of the 3 ingredients in Glutathione, Cysteine & C interact with drugs. Each result below shows which ingredient is responsible. Vitamin C L-Cysteine Hydrochloride
AcarboseGlucobay, Prandase, Precose
How Acarbose interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
L-cysteine HydrochlorideAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, taking L-cysteine supplements with antidiabetes drugs might increase the risk of hypoglycemia.
Read the full L-cysteine Hydrochloride + Acarbose interactionAcetohexamideDymelor
How Acetohexamide interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
L-cysteine HydrochlorideAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, taking L-cysteine supplements with antidiabetes drugs might increase the risk of hypoglycemia.
Read the full L-cysteine Hydrochloride + Acetohexamide interactionAlbiglutideTanzeum
How Albiglutide interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
L-cysteine HydrochlorideAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, taking L-cysteine supplements with antidiabetes drugs might increase the risk of hypoglycemia.
Read the full L-cysteine Hydrochloride + Albiglutide interactionAlginic Acid, Aluminum HydroxideRafton
How Alginic Acid, Aluminum Hydroxide interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAluminum Moderate
Interaction Summary
Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Read the full Vitamin C + Alginic Acid, Aluminum Hydroxide interactionAlogliptinNesina
How Alogliptin interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
L-cysteine HydrochlorideAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, taking L-cysteine supplements with antidiabetes drugs might increase the risk of hypoglycemia.
Read the full L-cysteine Hydrochloride + Alogliptin interactionAlogliptin, MetforminKazano
How Alogliptin, Metformin interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
L-cysteine HydrochlorideAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, taking L-cysteine supplements with antidiabetes drugs might increase the risk of hypoglycemia.
Read the full L-cysteine Hydrochloride + Alogliptin, Metformin interactionAlogliptin, PioglitazoneOseni
How Alogliptin, Pioglitazone interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
L-cysteine HydrochlorideAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, taking L-cysteine supplements with antidiabetes drugs might increase the risk of hypoglycemia.
Read the full L-cysteine Hydrochloride + Alogliptin, Pioglitazone interactionAltretamineHexalen
How Altretamine interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAlkylating Agents Moderate
Interaction Summary
Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
Read the full Vitamin C + Altretamine interactionAluminum Acetate, Benzethonium ChlorideBuro-Sol Otic Solution
How Aluminum Acetate, Benzethonium Chloride interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAluminum Moderate
Interaction Summary
Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Read the full Vitamin C + Aluminum Acetate, Benzethonium Chloride interactionAluminum ChlorideAluminum Chloride, Anhydrol Forte, Driclor, Drysol
How Aluminum Chloride interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAluminum Moderate
Interaction Summary
Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Read the full Vitamin C + Aluminum Chloride interactionAluminum HydroxideAlu-Cap, Amphojel, Gaviscon
How Aluminum Hydroxide interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAluminum Moderate
Interaction Summary
Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Read the full Vitamin C + Aluminum Hydroxide interactionAluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium HydroxideAscriptin Codeine #2
How Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium Hydroxide interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAspirin, Aluminum Moderate
Interaction Summary
Acidification of the urine by vitamin C might increase aspirin levels.
Read the full Vitamin C + Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium Hydroxide interactionAluminum Hydroxide, Aspirin, Magnesium HydroxideAscriptin
How Aluminum Hydroxide, Aspirin, Magnesium Hydroxide interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAspirin, Aluminum Moderate
Interaction Summary
Acidification of the urine by vitamin C might increase aspirin levels.
Read the full Vitamin C + Aluminum Hydroxide, Aspirin, Magnesium Hydroxide interactionAluminum Hydroxide, Magnesium Hydroxide (otc Drug)Maalox, Mucogel
How Aluminum Hydroxide, Magnesium Hydroxide (otc Drug) interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAluminum Moderate
Interaction Summary
Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Read the full Vitamin C + Aluminum Hydroxide, Magnesium Hydroxide (otc Drug) interactionAluminum Hydroxide, Magnesium Hydroxide, Simethicone (otc Drug)Mylanta
How Aluminum Hydroxide, Magnesium Hydroxide, Simethicone (otc Drug) interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAluminum Moderate
Interaction Summary
Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Read the full Vitamin C + Aluminum Hydroxide, Magnesium Hydroxide, Simethicone (otc Drug) interactionAluminum, CalciumDomeboro
How Aluminum, Calcium interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAluminum Moderate
Interaction Summary
Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Read the full Vitamin C + Aluminum, Calcium interactionAluminum, Magnesium (otc Drug)Almagel
How Aluminum, Magnesium (otc Drug) interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAluminum Moderate
Interaction Summary
Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Read the full Vitamin C + Aluminum, Magnesium (otc Drug) interactionAluminum, Magnesium Hydroxide (otc Drug)Wingel
How Aluminum, Magnesium Hydroxide (otc Drug) interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAluminum Moderate
Interaction Summary
Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Read the full Vitamin C + Aluminum, Magnesium Hydroxide (otc Drug) interactionAntidiabetes, Dipeptidyl Peptidase-4 (dpp-iv) InhibitorGlyxambi
How Antidiabetes, Dipeptidyl Peptidase-4 (dpp-iv) Inhibitor interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
L-cysteine HydrochlorideAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, taking L-cysteine supplements with antidiabetes drugs might increase the risk of hypoglycemia.
Read the full L-cysteine Hydrochloride + Antidiabetes, Dipeptidyl Peptidase-4 (dpp-iv) Inhibitor interactionAspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium HydroxideAscriptin Codeine #3
How Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAspirin, Aluminum Moderate
Interaction Summary
Acidification of the urine by vitamin C might increase aspirin levels.
Read the full Vitamin C + Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide interactionBazedoxifene Acetate, Conjugated EstrogensDuavee
How Bazedoxifene Acetate, Conjugated Estrogens interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CEstrogens Moderate
Interaction Summary
Vitamin C might increase blood levels of estrogens.
Read the full Vitamin C + Bazedoxifene Acetate, Conjugated Estrogens interactionBendamustineBelrapzo, Treanda, Vivimusta
How Bendamustine interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAlkylating Agents Moderate
Interaction Summary
Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
Read the full Vitamin C + Bendamustine interactionBendamustine HydrochlorideBendeka
How Bendamustine Hydrochloride interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAlkylating Agents Moderate
Interaction Summary
Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
Read the full Vitamin C + Bendamustine Hydrochloride interactionBleomycinBlenoxane
How Bleomycin interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAntitumor Antibiotics Moderate
Interaction Summary
Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.
Read the full Vitamin C + Bleomycin interactionBusulfanBusulfex, Myleran
How Busulfan interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAlkylating Agents Moderate
Interaction Summary
Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
Read the full Vitamin C + Busulfan interactionCanagliflozinInvokana
How Canagliflozin interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
L-cysteine HydrochlorideAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, taking L-cysteine supplements with antidiabetes drugs might increase the risk of hypoglycemia.
Read the full L-cysteine Hydrochloride + Canagliflozin interactionCanagliflozin, MetforminInvokamet
How Canagliflozin, Metformin interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
L-cysteine HydrochlorideAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, taking L-cysteine supplements with antidiabetes drugs might increase the risk of hypoglycemia.
Read the full L-cysteine Hydrochloride + Canagliflozin, Metformin interactionCanagliflozin, Metformin HydrochlorideInvokamet XR
How Canagliflozin, Metformin Hydrochloride interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
L-cysteine HydrochlorideAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, taking L-cysteine supplements with antidiabetes drugs might increase the risk of hypoglycemia.
Read the full L-cysteine Hydrochloride + Canagliflozin, Metformin Hydrochloride interactionCarboplatinParaplatin
How Carboplatin interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAlkylating Agents Moderate
Interaction Summary
Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
Read the full Vitamin C + Carboplatin interactionCarmustineBiCNU, Gliadel, Gliadel Wafer
How Carmustine interacts with Glutathione, Cysteine & C — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAlkylating Agents Moderate
Interaction Summary
Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
Read the full Vitamin C + Carmustine interactionEach ingredient & the kinds of drugs it affects
For each ingredient in Glutathione, Cysteine & C 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.
Vitamin C
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
L-Cysteine Hydrochloride
Antidiabetes Drugs
Theoretically, taking L-cysteine supplements with antidiabetes drugs might increase the risk of hypoglycemia.
Animal research suggests that L-cysteine can have hypoglycemic effects.
Brand information
Manufacturer and brand details for Glutathione, Cysteine & C, 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
Glutathione, Cysteine & C by Life Extension: Common Questions
Does Glutathione, Cysteine & C by Life Extension interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Can I take this if I'm on birth control?
Is this safe during pregnancy?
What's glutathione supposed to do?
Will this help me if I have a cold?
What are the side effects of vitamin C at high doses?
Is L-cysteine safe in high doses?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if Glutathione, Cysteine & C is safe with your meds?
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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.
The Full Monographs Behind Glutathione, Cysteine & C’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
L-cysteine
Interacts with 86 drugsL-cysteine is a sulfur-containing amino acid your body uses to make proteins and the antioxidant glutathione. Most people get enough from food, and supplements are usually well tolerated, bu...
Read the full L-cysteine monograph → Herb & supplement monographGlutathione
Glutathione is a powerful antioxidant your body makes naturally, and many people take it as a supplement hoping for skin, detox, or anti-aging benefits. However, strong human evidence is lim...
Read the full Glutathione monograph → Herb & supplement monographVitamin C
Interacts with 207 drugsVitamin 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 →Sources & How We Checked
Glutathione, Cysteine & C'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.
- NIH Dietary Supplement Label Database (DSLD) — The official product label on file for this supplement.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference behind the ingredient interaction data.
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 54 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.
L-cysteine 2 references
- Dowlati Y, Maheux M, Meyer JH. The effect of oral L-cysteine on breast milk and plasma cysteine concentrations. Neuropsychiatr Dis Treat 2020;16:3163-3172.
- Lee S, Han KH, Nakamura Y, et al. Dietary L-cysteine improves the antioxidative potential and lipid metabolism in rats fed a normal diet. Biosci Biotechnol Biochem 2013;77(7):1430-4.
Glutathione 1 reference
- Marrades RM, Roca J, Barbera JA, et al. Nebulized glutathione induces bronchoconstriction in patients with mild asthma. Am J Respir Crit Care Med 1997;156(2 Pt 1):425-30. PubMed
Vitamin C 51 references
- McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
- 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.
- Morris JC, Beeley L, Ballantine N. Interaction of ethinyloestradiol with ascorbic acid in man [letter]. Br Med J (Clin Res Ed) 1981;283:503.
- Labriola D, Livingston R. Possible interactions between dietary antioxidants and chemotherapy. Oncology 1999;13:1003-8.
- 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
- Levine M, Rumsey SC, Daruwala R, et al. Criteria and recommendations for vitamin C intake. JAMA 1999;281:1415-23. PubMed
- Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
- Segal S, Kaminski S. Drug-nutrient interactions. American Druggist 1996 Jul;42-8.
- 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/.
- Houston JB, Levy G. Drug biotransformation interactions in man VI: Acetaminophen and ascorbic acid. J Pharm Sci 1976;65:1218-21. PubMed
- 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
- Rosenthal G. Interaction of ascorbic acid and warfarin. JAMA 1971;215:1671. DOI
- Hume R, Johnstone JM, Weyers E. Interaction of ascorbic acid and warfarin. JAMA 1972;219:1479. DOI
- Smith EC, Skalski RJ, Johnson GC, Rossi GV. Interaction of ascorbic acid and warfarin. JAMA 1972;221:1166. DOI
- 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
- Domingo JL, Gomez M, Llobet JM, Richart C. Effect of ascorbic acid on gastrointestinal aluminum absorption (letter). Lancet 1991;338:1467.
- 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
- Partridge NA, Regnier FE, White JL, Hem SL. Influence of dietary constituents on intestinal absorption of aluminum. Kidney Int 1989;35:1413-7. PubMed
- Mc Leod DC, Nahata MC. Inefficacy of ascorbic acid as a urinary acidifier (letter). N Engl J Med 1977;296:1413. DOI
- Hansten PD, Hayton WL. Effect of antacid and ascorbic acid on serum salicylate concentration. J Clin Pharmacol 1980;20:326-31. PubMed
- Dysken MW, Cumming RJ, Channon RA, Davis JM. Drug interaction between ascorbic acid and fluphenazine. JAMA 1979;241:2008. DOI
- 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
- 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
- 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
- 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
- Weintraub M, Griner PF. Warfarin and ascorbic acid: lack of evidence for a drug interaction. Toxicol Appl Pharmacol 1974;28:53-6. PubMed
- 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
- 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
- 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
- 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
- Conklin KA. Cancer chemotherapy and antioxidants. J Nutr 2004;134:3201S-3204S. PubMed
- 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.
- 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.
- 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
- 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.
- 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.
- 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
- 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
- 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
- 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
- Rumbold A, Ota E, Nagata C, Shahrook S, Crowther CA. Vitamin C supplementation in pregnancy. Cochrane Database Syst Rev. 2015;(9):CD004072. PubMed
- 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
- 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
- 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.
- 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
- 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
- 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
- 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
- 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
- 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
- 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
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