Major interaction on record — check this product against your medications before combining. Based on 7 of 8 ingredients. Check your meds →
Dietary supplement

L.G.S. Ingredients & Drug Interactions

by Priority One Nutritional Supplements

L.G.S. label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking L.G.S. 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

L.G.S. is a dietary supplement by Priority One Nutritional Supplements with 8 active ingredients. Its ingredients are commonly taken for muscle recovery and sports performance, gut health and 'leaky gut', recovery from severe illness or injury.Based on those ingredients, 1,306 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Cat's Claw, Sunvitol, Vitamin A. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against L.G.S. by Priority One Nutritional Supplements

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

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of L.G.S. by Priority One Nutritional Supplements

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

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 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 8 of its 8 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

L.G.S. contains eight active ingredients: L-glutamine, vitamin A, gamma oryzanol, N-acetyl D-glucosamine, cat's claw, zinc, folate, and vitamin E (Sunvitol). L-glutamine is an amino acid; the vitamins and minerals support various body functions; gamma oryzanol is a plant compound; N-acetyl D-glucosamine supports joint structure; and cat's claw is a plant extract.

The product also contains inactive ingredients (rice, silicon dioxide, modified tapioca starch, and the capsule material) used as fillers and binders.

Does it work?

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

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

Strong

Strong clinical evidence supports its ingredients for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredients' overall clinical evidence instead.
  • On file: Sickle cell disease — rated "Effective" (Glutamine) (Natural Medicines).
  • On file: Vitamin A deficiency — rated "Effective" (Vitamin A) (Natural Medicines).
  • On file: Vitamin E deficiency — rated "Effective" (Vitamin E) (Natural Medicines).
  • On file: Zinc deficiency — rated "Effective" (Zinc) (Natural Medicines).
  • On file: Ataxia with vitamin E deficiency (AVED) — rated "Effective" (Vitamin E) (Natural Medicines).

The strongest evidence is for L-glutamine in sickle cell disease, which is rated effective. N-acetyl D-glucosamine is likely effective for osteoarthritis.

Several ingredients have possibly effective ratings for specific conditions: L-glutamine for HIV/AIDS-related wasting and recovery from trauma or surgery; vitamin A for oral leukoplakia, aging skin, measles, ulcerative colitis, and bronchopulmonary dysplasia; zinc for acne, age-related macular degeneration, and diabetes; and vitamin E for Alzheimer disease, beta-thalassemia, and G6PD deficiency. Gamma oryzanol is possibly effective for high cholesterol (dyslipidemia).

For other uses listed on the label — such as cat's claw for allergies, asthma, or Alzheimer disease — the evidence in our data is insufficient to rate. No effectiveness data is on file for folate in this product.

The evidence, ingredient by ingredient Glutamine Vitamin A Gamma-oryzanol Glucosamine Cat's Claw Zinc Vitamin E

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

L-glutamine is rated likely safe in pregnancy and lactation but should be used under medical supervision in people with kidney or liver disease. Vitamin A is generally safe at recommended amounts but high doses can cause birth defects; avoid high-dose supplements unless a doctor advises otherwise during pregnancy, and normal dietary amounts are fine while breastfeeding.

N-acetyl D-glucosamine should be avoided in pregnancy and breastfeeding due to lack of safety data. Gamma oryzanol is best avoided in pregnancy and while breastfeeding.

Cat's claw should be avoided in pregnancy (it has been used traditionally as an abortifacient) and while breastfeeding; it is generally well tolerated short-term in healthy adults but long-term safety is not well studied. Zinc is generally safe at recommended doses but high doses can cause harm; recommended amounts are appropriate in pregnancy and breastfeeding, but high-dose supplements should be avoided unless a doctor advises.

Vitamin E is safe at usual dietary amounts but high doses may increase bleeding risk; use recommended prenatal amounts in pregnancy, and check with your doctor before taking high-dose supplements while breastfeeding. Common side effects from these ingredients include gastrointestinal symptoms (nausea, bloating, constipation, diarrhea) and headache.

Side effects, ingredient by ingredient Glutamine Vitamin A Gamma-oryzanol Glucosamine Cat's Claw Zinc Vitamin E

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

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

Why this rating?
  • 6 of the 7 matched ingredients can interact with medications — Cat's Claw, Glucosamine, Glutamine, Vitamin E, Vitamin A, among others.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; seizure medications; immunosuppressants / transplant drugs; cancer treatments; diabetes medications.
  • For scale: 1,307 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.

Major interactions: retinoid drugs (acne medications) and warfarin (blood thinner). Moderate interactions: seizure medications, blood pressure drugs, immunosuppressants, tetracycline and quinolone antibiotics, cephalexin, penicillamine, some HIV medications (ritonavir, integrase inhibitors, Biktarvy, Paxlovir), some heart drugs (calcium channel blockers), chemotherapy drugs (alkylating agents, antitumor antibiotics, cisplatin, topoisomerase II inhibitors), and liver-stressing drugs.

Minor interactions with diabetes medications and niacin are also documented. Check all your current medications with the tool on this page before taking this product.

Check your own medication Run your meds through the checker above

The bottom line

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

L.G.S. may be worth considering if you have sickle cell disease (for glutamine) or osteoarthritis (for glucosamine) and have no drug interactions. If you take blood thinners like warfarin, seizure medications, tetracycline antibiotics, or retinoid acne drugs, do not start this product without checking with your pharmacist first — some ingredients pose serious risks.

Anyone with kidney or liver disease, or taking multiple medications, should talk with their pharmacist before use.

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

Assessment coverage: 7 of 8 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Nov 22, 2022.

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 L.G.S., straight from the product label.

Brand Priority One Nutritional Supplements
Barcode (UPC) 815354020846
Net contents 120 Capsule(s)
Market status On market
Date entered into DSLD Nov 22, 2022
DSLD ID 277388
Product type Other Combinations
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 L.G.S. by Priority One Nutritional Supplements, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
2 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
60
UPC/BARCODE
815354020846
IngredientAmount% DV
L-Glutamine500 mg--
Vitamin A8333 IU167%
Gamma Oryzanol120 mg--
N-Acetyl D-Glucosamine350 mg--
Cat's Claw150 mg--
Zinc4 mg27%
Folate260 mcg65%
Sunvitol60 IU200%

Other ingredients: Rice, Silicon Dioxide, modified Tapioca Starch, Capsule

Tap any ingredient to jump to its full detail below.

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

Warning: If you are pregnant or breast feeding, consult your physician before using this product.

Keep out of reach of children.

Suggested/Recommended/Usage/Directions

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

Storage

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

Formulation

Contains no preservatives.

(Mucosal Permeability Factor)

Non-GMO

General Statements

Bisphenol-A (BPA) & Phthalate Free

For professional use only.

Seals/Symbols

GMP Certified

Brand IP Statement(s)

Priority One Nutritional Supplements Inc since 1988

Quatrefolic is a registered trademark of Gnosis S.p.A. Protected by U.S. Patent No. 7,947,662

FDA Statement of Identity

A Dietary Supplement

FDA Disclaimer Statement

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

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

See for yourself

L.G.S. by Priority One Nutritional Supplements label

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

L.G.S. 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 L.G.S. by Priority One Nutritional Supplements

These are the 8 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 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.

L-Glutamine

Interacts with
50 drugs
500 mg per serving

Glutamine is the most abundant amino acid in the body and is usually made in your muscles. A prescription form is FDA-approved to help reduce sickle c...

L-Glutamine monograph & interactions

Vitamin A

Interacts with
387 drugs
8333 IU per serving Form: Beta-Carotene

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

Vitamin A monograph & interactions

Gamma Oryzanol

No known
interactions
120 mg per serving

Gamma-oryzanol is a mix of plant compounds taken from rice bran oil, used mainly for cholesterol, menopause symptoms, and as a sports supplement. The...

Gamma Oryzanol monograph & interactions

N-Acetyl D-Glucosamine

Interacts with
170 drugs
350 mg per serving

Glucosamine is a natural compound found in cartilage and joint fluid, and it is one of the most popular supplements for osteoarthritis, especially of...

N-Acetyl D-Glucosamine monograph & interactions

Cat's Claw

Interacts with
962 drugs
150 mg per serving

Cat's claw is a South American vine traditionally used for inflammation, joint pain, and immune support. Some small studies hint it may help with arth...

Cat's Claw monograph & interactions

Zinc

Interacts with
67 drugs
4 mg per serving Form: Zinc Chloride, Zinc Picolinate

Zinc is an essential mineral that your body needs for immune function, wound healing, taste, and smell. Most people get enough from food, but suppleme...

Zinc monograph & interactions

Folate

260 mcg per serving Form: (6S)-5-Methyltetrahydrofolic Acid

Sunvitol

Interacts with
764 drugs
60 IU per serving Form: Vitamin E

Vitamin E is an essential fat-soluble vitamin and antioxidant that most people get in adequate amounts from a normal diet. Supplements can help correc...

Sunvitol monograph & interactions

Other (inactive) ingredients: Rice, Silicon Dioxide, Modified Tapioca Starch, Capsule. These complete the product’s ingredient list but are not active constituents.

Interaction report

L.G.S. by Priority One Nutritional Supplements Drug Interactions

Want to check YOUR meds against L.G.S.?

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
1,306Drugs
11 Major 1,223 Moderate 72 Minor

Ingredients driving the most interactions

Cat's Claw 962
Sunvitol 764
Vitamin A 387
N-Acetyl D-Glucosamine 170
Zinc 67

Individual Drug Interactions

The ingredients in L.G.S. interact with 1,306 drugs. Click any drug to see the details.

6 of the 8 ingredients in L.G.S. interact with drugs. Each result below shows which ingredient is responsible. Cat's Claw Sunvitol Vitamin A N-Acetyl D-Glucosamine Zinc L-Glutamine

Each ingredient & the kinds of drugs it affects

For each ingredient in L.G.S. 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.

Cat's Claw6 drug types · 962 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, cat's claw may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Cat's claw contains rhynchophylline and isorhynchophylline. Animal research suggests that these alkaloids can inhibit platelet aggregation. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Antihypertensive Drugs

Theoretically, taking cat's claw with antihypertensive drugs might increase the risk of hypotension.
Cat's claw contains rhynchophylline. In vitro and animal research suggests that rhynchophylline can lower blood pressure. This interaction has not been reported in humans.

Likelihood Probable Evidence D
Calcium Channel Blockers

Theoretically, taking cat's claw with calcium channel blockers might increase the risk of hypotension.
Cat's claw contains various alkaloids, including rhynchophylline, isorhynchophylline, corynoxeine, and isocorynoxiene. Animal research suggests that these alkaloids can lower blood pressure by acting as calcium channel blockers. This interaction has not been reported in humans.

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

Theoretically, cat's claw might increase or decrease the levels and effects of drugs metabolized by CYP3A4.
Cat's claw may affect the clearance of drugs metabolized by CYP3A4. In vitro research shows that cat's claw can inhibit CYP3A4 enzymes. In one case report, a patient taking cat's claw (at an unspecified dose) experienced increased serum levels of atazanavir, ritonavir, and saquinavir, all of which are CYP3A4 substrates. Levels returned to normal 15 days after discontinuation of the cat's claw supplement, suggesting inhibition of CYP3A4 by cat's claw. In contrast, animal research suggests that rhynchophylline, an alkaloid contained in cat's claw, induces CYP3A expression and accelerates the metabolism of nirmatrelvir, the active component in the nirmatrelvir/ritonavir combination product.

Likelihood Possible Evidence D
Immunosuppressants

Theoretically, cat's claw might interfere with immunosuppressive therapy.
In human and laboratory research, cat's claw has been shown to have immunostimulating activity. It stimulates phagocytosis and increases respiratory cellular activity and the mobility of leukocytes. Theoretically, this could interfere with the activity of immunosuppressant medications.

Likelihood Possible Evidence D
Nirmatrelvir/Ritonavir (Paxlovid)

Theoretically, cat's claw may decrease the levels of nirmatrelvir.
Cat's claw contains rhynchophylline. Animal research suggests that this alkaloid induces CYP3A expression, thereby accelerating the metabolism of nirmatrelvir, the active component in the nirmatrelvir/ritonavir combination product. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Cat's Claw full monograph & interactions

Sunvitol8 drug types · 764 drugs

Alkylating Agents

Theoretically, antioxidant effects of vitamin E might reduce the effectiveness of alkylating agents.
There's concern that antioxidants could reduce the activity of chemotherapy drugs which generate free radicals, such as cyclophosphamide, chlorambucil, carmustine, busulfan, and thiotepa. However, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that might interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin E have on chemotherapy. Advise patients to consult their oncologist before using vitamin E supplements, especially in high doses.

Likelihood Possible Evidence D
Anticoagulant/Antiplatelet Drugs

Concomitant use of vitamin E and anticoagulant or antiplatelet agents might increase the risk of bleeding.
Vitamin E seems to inhibit of platelet aggregation and antagonize the effects of vitamin K-dependent clotting factors. These effects appear to be dose-dependent, and are probably only likely to be clinically significant with doses of at least 800 units daily. Mixed tocopherols, such as those found in food, might have a greater antiplatelet effect than alpha-tocopherol. RRR alpha-tocopherol (natural vitamin E) 1000 IU daily antagonizes vitamin K-dependent clotting factors. Advise patients to avoid high doses of vitamin E, especially in people with low vitamin K intake or other risk factors for bleeding.

Likelihood Possible Evidence B
Antitumor Antibiotics

Theoretically, antioxidant effects of vitamin E might reduce the effectiveness of antitumor antibiotics.
There's concern that antioxidants could reduce the activity of antitumor antibiotic drugs such as doxorubicin, which generate free radicals. However, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that might interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin E have on chemotherapy involving antitumor antibiotics. Advise patients to consult their oncologist before using vitamin E supplements, especially in high doses.

Likelihood Possible Evidence D
Cyclosporine (Neoral, Sandimmune)

A specific form of vitamin E might increase absorption and levels of cyclosporine.
There is some evidence that one specific formulation of vitamin E (D-alpha-tocopheryl-polyethylene glycol-1000 succinate, TPGS, tocophersolan, Liqui-E) might increase absorption of cyclosporine. This vitamin E formulation forms micelles which seems to increase absorption of cyclosporine by 40% to 72% in some patients. However, this interaction is unlikely to occur with the usual forms of vitamin E.

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

Theoretically, vitamin E might induce metabolism of CYP3A4, possibly reducing the levels CYP3A4 substrates.
Vitamin E appears to bind with the nuclear receptor, pregnane X receptor (PXR), which results in increased expression of CYP3A4. Although the clinical significance of this is not known, use caution when considering concomitant use of vitamin E and other drugs affected by these enzymes.

Likelihood Possible Evidence D
Selumetinib (Koselugo)

Taking selumetinib with vitamin E can result in a total daily dose of vitamin E that exceeds safe limits and therefore might increase the risk of bleeding.
Selumetinib contains 48-54 IU vitamin E per capsule. The increased risk of bleeding with vitamin E appears to be dose-dependent. Be cautious when using selumetinib in combination with supplemental vitamin E, especially in patients at higher risk of bleed, such as those with chronic conditions and those taking antiplatelet drugs.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Using vitamin E with warfarin might increase the risk of bleeding.
Due to interference with production of vitamin K-dependent clotting factors, use of more than 400 IU of vitamin E daily with warfarin might increase prothrombin time (PT), INR, and the risk of bleeding,. At a dose of 1000 IU per day, vitamin E can antagonize vitamin K-dependent clotting factors even in people not taking warfarin. Limited clinical evidence suggests that doses up to 1200 IU daily may be used safely by patients taking warfarin, but this may not be applicable in all patient populations.

Likelihood Possible Evidence B
Niacin

Vitamin E might decrease the beneficial effects of niacin on high-density lipoprotein (HDL) cholesterol levels.
A combination of niacin and simvastatin (Zocor) effectively raises high-density lipoprotein (HDL) cholesterol levels in people 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%. Vitamin E alone combined with a statin does not seem to decrease HDL levels. It is not known whether the adverse effect on HDL is due to one of the other antioxidants or to the combination. It also is not known whether it will occur in other patient populations.

Likelihood Possible Evidence A
Sunvitol full monograph & interactions

Vitamin A4 drug types · 387 drugs

Retinoids

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

Likelihood Probable Evidence D
Hepatotoxic Drugs

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

Likelihood Possible Evidence C
Tetracycline Antibiotics

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

Likelihood Possible Evidence D
Warfarin (Coumadin)

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

Likelihood Possible Evidence D
Vitamin A full monograph & interactions

N-Acetyl D-Glucosamine4 drug types · 170 drugs

Warfarin (Coumadin)

Glucosamine might increase the anticoagulant effects of warfarin and increase the risk of bruising and bleeding.
In two individual case reports, glucosamine/chondroitin combinations were associated with a significant increase in international normalized ratio (INR) in patients previously stabilized on warfarin. In one case, the increase in INR occurred only after tripling the dose of a glucosamine/chondroitin supplement from 500 mg/400 mg daily to 1500/1200 mg daily. Additionally, 20 voluntary case reports to the U.S. Food & Drug Administration (FDA) have linked glucosamine plus chondroitin with increased INR, bruising, and bleeding in patients who were also taking warfarin. There have also been 20 additional case reports to the World Health Organization (WHO) that link glucosamine alone to increased INR in patients taking warfarin. The mechanism of this interaction is unclear. Glucosamine is a small component of heparin, but is not thought to have anticoagulant activity; however, animal research suggests that it might have antiplatelet activity.

Likelihood Probable Evidence D
Topoisomerase Ii Inhibitors

Theoretically glucosamine may induce resistance to topoisomerase II inhibitors.
In vitro research suggests that glucosamine might induce resistance to etoposide (VP16, VePesid) and doxorubicin (Adriamycin) by reducing inhibition of topoisomerase II, an enzyme required for DNA replication in tumor cells. This effect has not been reported in humans.

Likelihood Possible Evidence D
Acetaminophen (Tylenol, Others)

Acetaminophen might interfere with the activity of glucosamine sulfate by interacting with the sulfate portion.
Anecdotal reports suggest that adding glucosamine to an acetaminophen regimen might decrease pain control in patients with osteoarthritis. Some research suggests that the sulfate portion of glucosamine sulfate might contribute to its effect in osteoarthritis. Since acetaminophen metabolism requires sulfur and reduces serum sulfate concentrations, acetaminophen could theoretically interfere with the action of glucosamine sulfate. Conversely, the administration of sulfate could theoretically decrease the effectiveness of acetaminophen in sulfate-deficient people by increasing its clearance.

Likelihood Possible Evidence B
Antidiabetes Drugs

Despite initial concerns, it is unlikely that glucosamine will interfere with the effects of antidiabetes drugs.
In vitro and animal research has suggested that glucosamine might increase insulin resistance or decrease insulin production. This has raised concerns that taking glucosamine might worsen diabetes and decrease the effectiveness of diabetes drugs. However, clinical research suggests that glucosamine does not have adverse effects on blood glucose or glycated hemoglobin (HbA1C) in healthy, obese, or type 2 diabetes patients.

Likelihood Unlikely Evidence B
N-Acetyl D-Glucosamine full monograph & interactions

Zinc10 drug types · 67 drugs

Bictegravir/Emtricitabine/Tenofovir Alafenamide (Biktarvy)

Theoretically, zinc might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption.
Advise patients that bictegravir/emtricitabine/tenofovir alafenamide should be taken at least 2 hours before or 6 hours after zinc containing products.

Likelihood Probable Evidence D
Cephalexin (Keflex)

Zinc might decrease cephalexin levels by chelating with cephalexin in the gut and preventing its absorption.
A pharmacokinetic study shows that zinc sulfate 250 mg taken concomitantly with cephalexin 500 mg decreases peak levels of cephalexin by 31% and reduces the exposure to cephalexin by 27%. Also, taking zinc sulfate 3 hours before cephalexin decreases peak levels of cephalexin by 11% and reduces the exposure to cephalexin by 18%. By decreasing cephalexin levels, zinc might increase the risk of treatment failure. This effect does not occur when zinc is taken 3 hours after the cephalexin dose. To avoid an interaction, advise patients take zinc sulfate 3 hours after taking cephalexin.

Likelihood Probable Evidence B
Cisplatin (Platinol-Aq)

Theoretically, zinc might interfere with the therapeutic effects of cisplatin.
Animal research suggests that zinc stimulates tumor cell production of the protein metallothionein, which binds and inactivates cisplatin. It is not known whether zinc supplements or high dietary zinc intake can cause clinically significant interference with cisplatin therapy. Cisplatin might also increase zinc excretion.

Likelihood Possible Evidence D
Integrase Inhibitors

Theoretically, taking zinc along with integrase inhibitors might decrease the levels and clinical effects of these drugs.
Zinc is a divalent cation. Pharmacokinetic studies have shown that other divalent cations such as calcium and iron can decrease blood levels of the integrase inhibitor dolutegravir through chelation.

Likelihood Possible Evidence D
Penicillamine (Cuprimine, Depen)

Zinc might reduce the levels and clinical effects of penicillamine.
By forming an insoluble complex with penicillamine, zinc interferes with penicillamine absorption and activity. Zinc supplements reduce the efficacy of low-dose penicillamine (0.5-1 gram/day), but do not seem to affect higher doses (1-2.75 gram/day), provided dosing times are separated. Advise patients to take zinc and penicillamine at least 2 hours apart.

Likelihood Probable Evidence B
Quinolone Antibiotics

Zinc can decrease the levels and clinical effects of quinolones antibiotics.
Quinolones form complexes with zinc in the gastrointestinal tract, reducing absorption of both the quinolone and zinc if taken at the same time. Advise patients to take these drugs at least 2 hours before, or 4-6 hours after, zinc supplements.

Likelihood Probable Evidence B
Ritonavir (Norvir)

Zinc modestly reduces levels of ritonavir.
Clinical research shows that zinc might reduce serum ritonavir levels by chelating with ritonavir in the gut and preventing its absorption. In patients with HIV, ritonavir is taken with atazanavir to prevent the metabolism and increase the effects of atazanavir. A pharmacokinetic study shows that, in patients being treated with atazanavir/ritonavir, co-administration of zinc sulfate (Solvazinc tablets) 125 mg as a single dose or as multiple daily doses for 2 weeks reduces plasma levels of ritonavir by about 16%. However, atazanavir levels still remains high enough to prevent HIV virus replication. Therefore, the decrease in ritonavir levels is not likely to be clinically significant.

Likelihood Probable Evidence B
Tetracycline Antibiotics

Zinc might reduce levels of tetracycline antibiotics.
Tetracyclines form complexes with zinc in the gastrointestinal tract, which can reduce absorption of both the tetracycline and zinc when taken at the same time. Taking zinc sulfate 200 mg with tetracycline reduces absorption of the antibiotic by 30% to 40%. Demeclocycline and minocycline cause a similar interaction. However, doxycycline does not seem to interact significantly with zinc. Advise patients to take tetracyclines at least 2 hours before, or 4-6 hours after, zinc supplements to avoid any interactions.

Likelihood Probable Evidence B
Amiloride (Midamor)

Amiloride can modestly reduce zinc excretion and increase zinc levels.
Clinical research shows that amiloride can reduce urinary zinc excretion, especially at doses of 10 mg per day or more. This zinc-sparing effect can help to counteract zinc losses caused by thiazide diuretics, but it is unlikely to cause zinc toxicity at usual amiloride doses. The other potassium-sparing diuretics, spironolactone (Aldactone) and triamterene (Dyrenium), do not seem to have a zinc-sparing effect.

Likelihood Probable Evidence B
Atazanavir (Reyataz)

Zinc modestly reduces levels of atazanavir, although this effect does not seem to be clinically significant.
Clinical research shows that zinc might decrease serum atazanavir levels by chelating with atazanavir in the gut and preventing its absorption. Although a single dose of zinc sulfate (Solvazinc tablets) 125 mg orally does not affect atazanavir concentrations in patients being treated with atazanavir/ritonavir, co-administration of zinc sulfate 125 mg daily for 2 weeks reduces plasma levels of atazanavir by about 22% in these patients. However, despite this decrease, atazanavir levels still remain at high enough concentrations for the prevention of HIV virus replication.

Likelihood Probable Evidence B
Zinc full monograph & interactions

L-Glutamine1 drug type · 50 drugs

Anticonvulsants

Theoretically, glutamine might antagonize the effects of anticonvulsant medications.
Glutamine is metabolized to the excitatory neurotransmitter glutamate. Glutamate might have antagonistic effects with anticonvulsant drugs. However, this interaction has not yet been reported in humans.

Likelihood Possible Evidence D
L-Glutamine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for L.G.S., from the product label.

Priority One Nutritional Supplements

See all Priority One Nutritional Supplements products
Name
Priority One Nutritional Supplements, Inc.
Pharmacist Counseling Corner

L.G.S. by Priority One Nutritional Supplements: Common Questions

Does L.G.S. by Priority One Nutritional Supplements interact with any medications?
Yes. Based on its ingredients, L.G.S. has a known interaction with 1,306 medications, including 11 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
L.G.S. contains 8 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.
Is this safe to take if I'm pregnant or breastfeeding?
It depends on which ingredients and how much. L-glutamine is likely safe in pregnancy and lactation. Vitamin A is likely safe at normal amounts but high doses can cause birth defects — stick to recommended prenatal amounts. N-acetyl D-glucosamine, gamma oryzanol, and cat's claw lack enough safety data and should be avoided unless your doctor advises otherwise. Zinc at recommended amounts is fine; vitamin E at normal dietary amounts is okay. Talk with your pharmacist or doctor before starting, since the product contains multiple ingredients.
What is L-glutamine in this supplement supposed to do?
L-glutamine is an amino acid that is effective for sickle cell disease and possibly helpful for recovery from surgery or trauma and for HIV/AIDS-related wasting. It's generally well tolerated, though some people experience gas, bloating, constipation, or nausea.
Is the glucosamine in this product proven to work for joint health?
Yes — N-acetyl D-glucosamine (a form of glucosamine) is rated likely effective for osteoarthritis. For back pain and other uses, the evidence in our data is insufficient. Common side effects include bloating, nausea, and constipation.
What is cat's claw, and does it work?
Cat's claw is a plant extract. The evidence in our data is insufficient to rate its effectiveness for the conditions it's used for — allergies, asthma, Alzheimer disease, and others. It's generally well tolerated short-term in healthy adults but long-term safety is not well established.
Can I take this if I'm on blood thinners like warfarin?
No, not without checking with your pharmacist first. Two ingredients in this product — vitamin A (at high doses) and N-acetyl D-glucosamine — interact with warfarin and can increase bleeding risk. Do not start this supplement if you take warfarin without talking to your pharmacist.
Are there any fillers in this product?
Yes. In addition to the active ingredients, the product contains rice, silicon dioxide, and modified tapioca starch as inactive ingredients, plus the capsule material.

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.

L.G.S. label
Go deeper

The Full Monographs Behind L.G.S.’s Ingredients

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

Herb & supplement monograph

Glutamine

Interacts with 50 drugs

Glutamine is the most abundant amino acid in the body and is usually made in your muscles. A prescription form is FDA-approved to help reduce sickle cell disease complications, but for most...

Read the full Glutamine monograph → Herb & supplement monograph

Vitamin A

Interacts with 387 drugs

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

Read the full Vitamin A monograph → Herb & supplement monograph

Gamma-oryzanol

Gamma-oryzanol is a mix of plant compounds taken from rice bran oil, used mainly for cholesterol, menopause symptoms, and as a sports supplement. The evidence is limited and mostly comes fro...

Read the full Gamma-oryzanol monograph → Herb & supplement monograph

Glucosamine

Interacts with 170 drugs

Glucosamine is a natural compound found in cartilage and joint fluid, and it is one of the most popular supplements for osteoarthritis, especially of the knee. The evidence is mixed, with so...

Read the full Glucosamine monograph → Herb & supplement monograph

Cat's Claw

Interacts with 962 drugs

Cat's claw is a South American vine traditionally used for inflammation, joint pain, and immune support. Some small studies hint it may help with arthritis symptoms, but the overall evidence...

Read the full Cat's Claw monograph → Herb & supplement monograph

Zinc

Interacts with 67 drugs

Zinc is an essential mineral that your body needs for immune function, wound healing, taste, and smell. Most people get enough from food, but supplements can help correct or prevent a defici...

Read the full Zinc monograph → Herb & supplement monograph

Vitamin E

Interacts with 764 drugs

Vitamin E is an essential fat-soluble vitamin and antioxidant that most people get in adequate amounts from a normal diet. Supplements can help correct a true deficiency, but high-dose vitam...

Read the full Vitamin E monograph →
Sources

Sources & How We Checked

L.G.S.'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 268 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.

Glutamine 11 references
  1. Miller AL. Therapeutic considerations of L-glutamine: a review of the literature. Altern Med Rev 1999;4:239-48..
  2. Bozzetti F, Biganzoli L, Gavazzi C, et al. Glutamine supplementation in cancer patients receiving chemotherapy: a double-blind randomized study. Nutrition 1997;13:748-51.. PubMed
  3. Mebane AH. L-Glutamine and mania. Am J Psychiatry 984;141:1302-3.
  4. Meldrum BS. Glutamate as a neurotransmitter in the brain: review of physiology and pathology. J Nutr 2000;130:1007S-15S.. PubMed
  5. Garlick PJ. Assessment of the safety of glutamine and other amino acids. J Nutr 2001;131:2556S-61S.. PubMed
  6. Chapman AG. Glutamate and epilepsy. J Nutr 2000;130:1043S-5S.. PubMed
  7. Ziegler TR. Glutamine supplementation in cancer patients receiving bone marrow transplantation and high dose chemotherapy. J Nutr 2001;131:2578S-84S.. PubMed
  8. Laviano A, Molfino A, Lacaria MT, Canelli A, De Leo S, Preziosa I, Rossi Fanelli F. Glutamine supplementation favors weight loss in nondieting obese female patients. A pilot study. Eur J Clin Nutr. 2014 Nov;68(11):1264-6. PubMed
  9. Endari (l-glutamine) [package insert]. Torrance, CA: Emmaus Medical,Inc; 2017.
  10. Niihara Y, Miller ST, Kanter J, et al. A Phase 3 Trial of l-Glutamine in Sickle Cell Disease. N Engl J Med 2018;379(3):226-35. doi: 10.1056/NEJMoa1715971.
  11. Ogden HB, Child RB, Fallowfield JL, et al. Gastrointestinal Tolerance of Low, Medium and High Dose Acute Oral l-Glutamine Supplementation in Healthy Adults: A Pilot Study. Nutrients. 2020;12(10):2953. PubMed

See these in context on the Glutamine monograph →

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

See these in context on the Vitamin A monograph →

Glucosamine 58 references
  1. Adams ME. Hype about glucosamine. Lancet 1999;354:353-4. PubMed
  2. Balkan B, Dunning BE. Glucosamine inhibits glucokinase in vitro and produces a glucose-specific impairment of in vivo insulin secretion in rats. Diabetes 1994;43:1173-9. PubMed
  3. Giaccari A, Morviducci L, Zorretta D, et al. In vivo effects of glucosamine on insulin secretion and insulin sensitivity in the rat: possible relevance to the maladaptive responses to chronic hyperglycaemia. Diabetologia 1995;38:518-24. PubMed
  4. Holmang A, Nilsson C, Niklasson M, et al. Induction of insulin resistance by glucosamine reduces blood flow but not interstitial levels of either glucose or insulin. Diabetes 1999;48:106-11. PubMed
  5. Houpt JB, McMillan R, Wein C, Paget-Dellio SD. Effect of glucosamine hydrochloride in the treatment of pain of osteoarthritis of the knee. J Rheumatol 1999;26:2423-30.
  6. Barclay TS, Tsourounis C, McCart GM. Glucosamine. Ann Pharmacother 1998;32:574-9.
  7. Shankar RR, Zhu JS, Baron AD. Glucosamine infusion in rats mimics the beta-cell dysfunction of non-insulin-dependent diabetes mellitus. Metabolism 1998;47:573-7.
  8. Almada A, Harvey P, Platt K. Effects of chronic oral glucosamine sulfate on fasting insulin resistance index (FIRI) in non-diabetic individuals. FASEB J 2000;14:A750.
  9. Reginster JY, Deroisy R, Rovati LC, et al. Long-term effects of glucosamine sulfate on osteoarthritis progression: a randomised, placebo-controlled trial. Lancet 2001;357:251-6.
  10. Does glucosamine increase serum lipid levels and blood pressure? Pharmacist's Letter/Prescriber's Letter 2001;17(11):171115.
  11. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
  12. Monauni T, Zenti MG, Cretti A, et al. Effects of glucosamine infusion on insulin secretion and insulin action in humans. Diabetes 2000;49:926-35. PubMed
  13. Pouwels MJ, Jacobs JR, Span PN, et al. Short-term glucosamine infusion does not affect insulin sensitivity in humans. J Clin Endocrinol Metab 2001;86:2099-103. DOI
  14. Yun J, Tomida A, Nagata K, Tsuruo T. Glucose-regulated stresses confer resistance to VP-16 in human cancer cells through a decreased expression of DNA topoisomerase II. Oncol Res 1995;7:583-90.
  15. Pavelka K, Gatterova J, Olejarova M, et al. Glucosamine sulfate use and delay of progression of knee osteoarthritis: A 3-year, randomized, placebo-controlled, double-blind study. Arch Intern Med 2002;162:2113-23. PubMed
  16. Tallia AF, Cardone DA. Asthma exacerbation associated with glucosamine-chondroitin supplement. J Am Board Fam Pract 2002;15:481-4..
  17. Scroggie DA, Albright A, Harris MD. The effect of glucosamine-chondroitin supplementation on glycosylated hemoglobin levels in patients with type 2 diabetes mellitus: a placebo-controlled, double-blinded, randomized clinical trial. Arch Intern Med 2003; PubMed
  18. Hoffer LJ, Kaplan LN, Hamadeh MJ, et al. Sulfate could mediate the therapeutic effect of glucosamine sulfate. Metabolism 2001;50:767-70.. PubMed
  19. Yu JG, Boies SM, Olefsky JM. The effect of oral glucosamine sulfate on insulin sensitivity in human subjects. Diabetes Care 2003;26:1941-2. PubMed
  20. Danao-Camara T. Potential side effects of treatment with glucosamine and chondroitin. Arthritis Rheum 2000;43:2853. PubMed
  21. Guillaume MP, Peretz A. Possible association between glucosamine treatment and renal toxicity: comment on the letter by Danao-Camara. Arthritis Rheum 2001;44:2943-4. PubMed
  22. Rozenfeld V, Crain JL, Callahan AK. Possible augmentation of warfarin effect by glucosamine-chondroitin. Am J Health Syst Pharm 2004;61:306-307. PubMed
  23. Tannis AJ, Barban J, Conquer JA. Effect of glucosamine supplementation on fasting and non-fasting plasma glucose and serum insulin concentrations in healthy individuals. Osteoarthritis Cartilage 2004;12:506-11. PubMed
  24. Bush TM, Rayburn KS, Holloway SW, et al. Adverse interactions between herbal and dietary substances and prescription medications: a clinical survey. Altern Ther Health Med 2007;13:30-5.
  25. Stumpf JL, Lin SW. Effect of glucosamine on glucose control. Ann Pharmacother 2006;40:694-8. PubMed
  26. Pham T, Cornea A, Blick KE, et al. Oral glucosamine in doses used to treat osteoarthritis worsens insulin resistance. Am J Med Sci 2007;333:333-9. PubMed
  27. Muniyappa R, Karne RJ, Hall G, et al. Oral glucosamine for 6 weeks at standard doses does not cause or worsen insulin resistance or endothelial dysfunction in lean or obese subjects. Diabetes 2006;55:3142-50. PubMed
  28. Knudsen J, Sokol GH. Potential glucosamine-warfarin interaction resulting in increased international normalized ratio: Case report and review of the literature and MedWatch database. Pharmacotherapy 2008;28:540-8. PubMed
  29. Yue QY, Strandell J, Myrberg O. Concomitant use of glucosamine potentiates the effect of warfarin. Jan 2006. Drug Safety 29(10):911-1010. DOI
  30. Rozendaal RM, Koes BW, van Osch GJVM, et al. Effect of glucosamine sulfate on hip osteoarthritis: A randomized trial. Ann Intern Med 2008;148:268-77. PubMed
  31. Baron AD, Zhu JS, Zhu JH, et al. Glucosamine induces insulin resistance in vivo by affecting GLUT 4 translocation in skeletal muscle. Implications for glucose toxicity. J Clin Invest 1995;96(6):2792-801. PubMed
  32. Nelson BA, Robinson KA, Buse MG. High glucose and glucosamine induce insulin resistance via different mechanisms in 3T3-L1 adipocytes. Diabetes 2000;49(6):981-91. PubMed
  33. Giordano N, Fioravanti A, Papakostas P, et al. The efficacy and tolerability of glucosamine sulfate in the treatment of knee osteoarthritis: a randomized, double-blind, placebo-controlled trial. Curr Ther Res Clin Exp 2009;70(3):185-196. PubMed
  34. Shaygannejad, V., Janghorbani, M., Savoj, M. R., and Ashtari, F. Effects of adjunct glucosamine sulfate on relapsing-remitting multiple sclerosis progression: preliminary findings of a randomized, placebo-controlled trial. Neurol Res 2010;32(9):981-985. PubMed
  35. Cahlin, B. J. and Dahlstrom, L. No effect of glucosamine sulfate on osteoarthritis in the temporomandibular joints--a randomized, controlled, short-term study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;112(6):760-766. PubMed
  36. Cerda C, Bruguera M, Parés A. Hepatotoxicity associated with glucosamine and chondroitin sulfate in patients with chronic liver disease. World J Gastroenterol 2013;19(32):5381-4. PubMed
  37. Hochberg MC, Martel-Pelletier J, Monfort J, Möller I, Castillo JR, Arden N,Berenbaum F, Blanco FJ, Conaghan PG, Doménech G, Henrotin Y, Pap T, Richette P, Sawitzke A, du Souich P, Pelletier JP; on behalf of the MOVES Investigation Group. Combined chondroi
  38. von Felden J, Montani M, Kessebohm K, Stickel F. Drug-induced acute liver injury mimicking autoimmune hepatitis after intake of dietary supplements containing glucosamine and chondroitin sulfate. Int J Clin Pharmacol Ther 2013;51(3):219-23. PubMed
  39. Provenza JR, Shinjo SK, Silva JM, Peron CR, Rocha FA. Combined glucosamine and chondroitin sulfate, once or three times daily, provides clinically relevant analgesia in knee osteoarthritis. Clin Rheumatol 2015;34:1455-62. PubMed
  40. Ossendza RA, Grandval P, Chinoune F, Rocher F, Chapel F, Bernardini D. [Acute cholestatic hepatitis due to glucosamine forte]. Gastroenterol Clin Biol. 2007 Apr;31(4):449-50.
  41. Audimoolam VK, Bhandari S. Acute interstitial nephritis induced by glucosamine. Nephrol Dial Transplant 2006;21(7):2031. PubMed
  42. Greenlee H, Crew KD, Shao T, Kranwinkel G, Kalinsky K, Maurer M, Brafman L, Insel B, Tsai WY, Hershman DL. Phase II study of glucosamine with chondroitin on aromatase inhibitor-associated joint symptoms in women with breast cancer. Support Care Cancer 201 PubMed
  43. Wilkens, P., Scheel, I. B., Grundnes, O., Hellum, C., and Storheim, K. Effect of glucosamine on pain-related disability in patients with chronic low back pain and degenerative lumbar osteoarthritis: a randomized controlled trial. JAMA 2010;304(1):45-52. PubMed
  44. Simon RR, Marks V, Leeds AR, Anderson JW. A comprehensive review of oral glucosamine use and effects on glucose metabolism in normal and diabetic individuals. Diabetes Metab Res Rev 2011;27(1):14-27. PubMed
  45. Smidt D, Torpet LA, Nauntofte B, Heegaard KM, Pedersen AM. Associations between labial and whole salivary flow rates, systemic diseases and medications in a sample of older people. Community Dent Oral Epidemiol 2010;38(5):422-35. PubMed
  46. Wangroongsub Y, Tanavalee A, Wilairatana V, Ngarmukos S. Comparable clinical outcomes between glucosamine sulfate-potassium chloride and glucosamine sulfate sodium chloride in patients with mild and moderate knee osteoarthritis: a randomized, double-blind
  47. Chopra A, Saluja M, Tillu G, Venugopalan A, Sarmukaddam S, Raut AK, Bichile L, Narsimulu G, Handa R, Patwardhan B. A Randomized Controlled Exploratory Evaluation of Standardized Ayurvedic Formulations in Symptomatic Osteoarthritis Knees: A Government of I
  48. Swinburne LM. Glucosamine sulphate and osteoarthritis. Lancet 2001;357(9268):1617. PubMed
  49. Murphy RK, Ketzler L, Rice RD, Johnson SM, Doss MS, Jaccoma EH. Oral glucosamine supplements as a possible ocular hypertensive agent. JAMA Ophthalmol 2013;131(7):955-7. PubMed
  50. Kimball AB, Kaczvinsky JR, Li J, et al. Reduction in the appearance of facial hyperpigmentation after use of moisturizers with a combination of topical niacinamide and N-acetyl glucosamine: results of a randomized, double-blind, vehicle-controlled trial.
  51. Ma H, Li X, Sun D, et al. Association of habitual glucosamine use with risk of cardiovascular disease: prospective study in UK Biobank. BMJ. 2019 May 14;365:l1628. PubMed
  52. Hoban C, Byard R, Musgrave I. Hypersensitive adverse drug reactions to glucosamine and chondroitin preparations in Australia between 2000 and 2011. Postgrad Med J. 2019 Oct 9. pii: postgradmedj-2019-136957. PubMed
  53. Tenti S, Veronese N, Cheleschi S, et al. Prescription-grade crystalline glucosamine sulfate as an add-on therapy to conventional treatments in erosive osteoarthritis of the hand: results from a 6-month observational retrospective study. Aging Clin Exp Res PubMed
  54. Yu H, Wu J, Chen H, et al. Glucosamine use is associated with a higher risk of cardiovascular diseases in patients with osteoarthritis: results from a large study in 685,778 subjects. Nutrients 2022;14(18):3694. PubMed
  55. Chu EC, Huang KHK, Cheung G, Ng G, Lin A. Delayed Skin Allergy to Glucosamine Chondroitin Supplement. Cureus 2023;15(3):e36310. PubMed
  56. Lila AM, Alekseeva LI, Baranov AA, et al. Chondroitin sulfate and glucosamine combination in patients with knee and hip osteoarthritis: A long-term observational study in Russia. World J Orthop 2023;14(6):443-457. PubMed
  57. Lehrer S, Morello T, Karrasch C, Rheinstein PH, Danias J. Effect of Glucosamine on Intraocular Pressure and Risk of Developing Glaucoma. J Glaucoma 2023. PubMed
  58. Rabade A, Viswanatha GL, Nandakumar K, Kishore A. Evaluation of efficacy and safety of glucosamine sulfate, chondroitin sulfate, and their combination regimen in the management of knee osteoarthritis: a systematic review and meta-analysis. Inflammopharmac PubMed

See these in context on the Glucosamine monograph →

Cat's Claw 16 references
  1. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  2. Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
  3. Sandoval M, Charbonnet RM, Okuhama NN, et al. Cat's claw inhibits TNFalpha production and scavenges free radicals: role in cytoprotection. Free Radic Biol Med 2000;29:71-78.
  4. Müller AC, Kanfer I. Potential pharmacokinetic interactions between antiretrovirals and medicinal plants used as complementary and African traditional medicines. Biopharm Drug Dispos. 2011;32(8):458-70. PubMed
  5. Sheng, Y., Bryngelsson, C., and Pero, R. W. Enhanced DNA repair, immune function and reduced toxicity of C-MED-100, a novel aqueous extract from Uncaria tomentosa. J Ethnopharmacol. 2000;69(2):115-126. PubMed
  6. Lamm, S., Sheng, Y., and Pero, R. W. Persistent response to pneumococcal vaccine in individuals supplemented with a novel water soluble extract of Uncaria tomentosa, C-Med-100. Phytomedicine 2001;8(4):267-274.
  7. Sheng, Y., Li, L., Holmgren, K., and Pero, R. W. DNA repair enhancement of aqueous extracts of Uncaria tomentosa in a human volunteer study. Phytomedicine 2001;8(4):275-282.
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See these in context on the Vitamin E monograph →

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

© 2021 Therapeutic Research Center, LLC

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