Drug & supplement interaction

Glucosamine + Orlistat

Orlistat brand names: Xenical, Alli.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Glucosamine and Orlistat in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Glucosamine and Orlistat

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Orlistat and Glucosamine in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Glucosamine safety at a glance

Glucosamine overall Use caution Generally well tolerated by most adults, but quality and benefit vary and certain people should be careful.
Pregnancy Avoid There is not enough safety information, so it is best to avoid during pregnancy.
Breastfeeding Avoid Not enough is known about safety while breastfeeding, so avoid unless your doctor advises otherwise.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Orlistat and Glucosamine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Orlistat

Interactions in our licensed database are recorded against drug classes, not just single drug names. Orlistat is filed under 2 classifications — including oral drugs. Glucosamine has documented interactions with 4 drug classes — the most serious being warfarin (coumadin) (major), topoisomerase ii inhibitors (moderate) and acetaminophen (tylenol, others) (minor) — and none of Orlistat’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Glucosamine Does Interact With Other Medications

Glucosamine has 2 major, 13 moderate, 155 minor known drug interactions in our database — Orlistat isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Glucosamine

Covers the 2,830 medications we’ve checked against Glucosamine. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Glucosamine and Orlistat May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. 5 of them are worth acting on rather than waiting out — marked below.

  • Wheezing Worth acting on Additional detail

    Glucosamine

    “Cases of asthma exacerbations associated with the use of glucosamine (form unknown)-chondroitin products have been reported.”

    Glucosamine · Natural Medicines adverse-effect record, reported in asthma.

    1 source cited
    1. 10002. Tallia AF, Cardone DA. Asthma exacerbation associated with glucosamine-chondroitin supplement. J Am Board Fam Pract 2002;15:481-4..

    Orlistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Orlistat. Read the label on DailyMed ›

  • A severe allergic reaction / Hives Worth acting on Additional detail

    Glucosamine

    “There is some concern that glucosamine products might cause allergic reactions in sensitive individuals. One review of glucosamine-related adverse events in Australia found that 72% of all reports involved hypersensitivity reactions.”

    Glucosamine · Natural Medicines adverse-effect record, reported in allergic rhinitis (hay fever).

    2 sources cited
    1. 102115. 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
    2. 89516. 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

    Orlistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Orlistat. Read the label on DailyMed ›

  • Liver problems Worth acting on Additional detail

    Glucosamine

    “Orally, all forms of glucosamine seem to be well tolerated. Topically and rectally, N-acetyl glucosamine also seems to be well tolerated. Intramuscularly, glucosamine sulfate seems to be well tolerated.”

    Glucosamine · Natural Medicines adverse-effect record, reported in constipation.

    “Although relatively uncommon, combinations of glucosamine and chondroitin sulfate have been associated with acute liver injury that mimics autoimmune hepatitis. Of 151 patients at an outpatient clinic for liver diseases, 23 acknowledged use of products containing glucosamine (form unspecified) and/or chondroitin.”

    Glucosamine · Natural Medicines adverse-effect record, reported in hepatitis.

    3 sources cited
    1. 89515. 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
    2. 89518. 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
    3. 89522. 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.

    Orlistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Orlistat. Read the label on DailyMed ›

  • An allergic reaction Worth acting on Additional detail

    Glucosamine

    Recorded for Glucosamine in the same Natural Medicines adverse-effect record shown under Liver problems above.

    Orlistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Orlistat. Read the label on DailyMed ›

  • Bloating or gas / Diarrhea reported in 7.6% of FDA reports for Orlistat Additional detail

    Glucosamine

    “Orally, glucosamine has been associated with gastrointestinal problems, including epigastric and abdominal pain, cramps, heartburn, diarrhea, nausea, dyspepsia, vomiting, constipation, and flatulence. In older persons, use of glucosamine sulfate is associated with oral dryness. In a clinical trial, a case of Helicobacter pylori gastritis was considered probably related to the use of glucosamine hydrochloride.”

    Glucosamine · Natural Medicines adverse-effect record, reported in constipation.

    6 sources cited
    1. 1520. 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.
    2. 2608. Barclay TS, Tsourounis C, McCart GM. Glucosamine. Ann Pharmacother 1998;32:574-9.
    3. 16717. 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
    4. 20084. 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
    5. 20104. 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
    6. 20105. 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

    Orlistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Orlistat, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • Itching Additional detail

    Glucosamine

    “Orally, glucosamine might cause skin reactions, including itching, rash, and erythema. Also, fingernail and toenail toughening, with an increased rate of growth, has been reported. Topically, N-acetyl glucosamine 2% with niacinamide 4% cream might cause rare skin reactions.”

    Glucosamine · Natural Medicines adverse-effect record, reported in erythema.

    6 sources cited
    1. 2608. Barclay TS, Tsourounis C, McCart GM. Glucosamine. Ann Pharmacother 1998;32:574-9.
    2. 20084. 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
    3. 89567. 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
    4. 110628. Chu EC, Huang KHK, Cheung G, Ng G, Lin A. Delayed Skin Allergy to Glucosamine Chondroitin Supplement. Cureus 2023;15(3):e36310. PubMed
    5. 113636. 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
    6. 89572. Swinburne LM. Glucosamine sulphate and osteoarthritis. Lancet 2001;357(9268):1617. PubMed

    Orlistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Orlistat. Read the label on DailyMed ›

  • Swelling Additional detail

    Glucosamine

    Recorded for Glucosamine in the same Natural Medicines adverse-effect record shown under A severe allergic reaction / Hives above.

    Orlistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Orlistat. Read the label on DailyMed ›

  • Stomach pain Additional detail

    Glucosamine

    Recorded for Glucosamine in the same Natural Medicines adverse-effect record shown under Bloating or gas / Diarrhea above.

    Orlistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Orlistat. Read the label on DailyMed ›

Showing the 10 most notable of 14 shared effects — ranked by how unusual each one is, not just whether both lists mention it.

Reported for Glucosamine but not commonly for Orlistat: sun sensitivity, unsteadiness, kidney problems and constipation.

Effects for Orlistat come from the ADVERSE REACTIONS section of its FDA label; effects for Glucosamine come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 25,755 voluntary FDA FAERS reports for Orlistat that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Overlapping uses

What Orlistat Is Prescribed For, and What Glucosamine Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Orlistat is a prescription medicine with approved uses on its FDA label. Glucosamine is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Orlistat is prescribed for: Xenical and prescription-strength orlistat are approved to help obese adults lose weight and keep it off when used with a reduced-calorie diet. They are intended for people with a body mass index (BMI) of 30 or higher, or 27 or higher if other risk factors such as high blood pressure, diabetes, or dyslipidemia (abnormal cholesterol or fat levels in the blood) are present. Alli is the over-the-counter version, approved for weight loss in overweight adults 18 and older when used with a reduced-calorie, low-fat diet and exercise program.

Glucosamine has been studied for:

  • Diabetes studied, not established Glucosamine has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Glucosamine for diabetes

    It is unclear if oral glucosamine reduces the risk of developing type 2 diabetes in adults.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Orlistat on your own; if you are taking Glucosamine for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Glucosamine or Orlistat

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Glucosamine or Orlistat, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Orlistat

This page covers Glucosamine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Orlistat page lists 18 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Fish Oil (moderate) and Glucomannan (moderate).

By severity: 1 major · 8 moderate · 9 minor.

From our pharmacist’s overview on the Orlistat page

“People who take Orlistat (Xenical, Alli) for weight loss often browse the very supplement aisle where fiber products and fish oil sit, and both show up on this page, so it deserves genuine attention before you mix anything in. Nearly all 18 ingredients on file can change how oral medications absorb from the gut, and the single major-ra…”

Reviewed by 2 · Jul 18, 2026

Open the Orlistat interaction page

One more smart check

Taking Glucosamine as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,984 real supplement products containing Glucosamine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Glucosamine. Even though Glucosamine itself has no known interaction with Orlistat, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Glucosamine and Orlistat Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Glucosamine
Top 10%

#106 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Orlistat
Top 25%

#519 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Glucosamine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Glucosamine and Orlistat records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Glucosamine

What is Glucosamine?

Glucosamine
  • Osteoarthritis
  • Joint pain and stiffness
  • Cartilage support
  • Knee and hip joint health

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 some people getting modest relief while others get little to no benefit. It is generally well tolerated, but talk to your pharmacist or doctor before starting it, especially if you have a shellfish allergy or diabetes.

Derived from shellfish exoskeletons (shrimp, crab, lobster) or made synthetically; also from fungal sources · Capsules, tablets, powders, liquids; often combined with chondroitin or MSM

An interaction check asks whether these two react with each other — it does not ask whether Glucosamine is a good idea for someone in your situation. Here is what our Glucosamine record says about it on its own.

Glucosamine: dosing

There is no single official dose of glucosamine, and the right amount can depend on the form and product. If you do not notice any benefit after a reasonable trial of a couple of months, it is worth discussing whether to continue.

From our Glucosamine monograph — the full record covers uses, side effects and every documented interaction.

Read the full Glucosamine monograph & all interactions
Medication

About Orlistat

What Is Orlistat Used For?

Brand names: Xenical, Alli

Xenical and prescription-strength orlistat are approved to help obese adults lose weight and keep it off when used with a reduced-calorie diet. They are intended for people with a body mass index (BMI) of 30 or higher, or 27 or higher if other risk factors such as high blood pressure, diabetes, or dyslipidemia (abnormal cholesterol or fat levels in the blood) are present.

Alli is the over-the-counter version, approved for weight loss in overweight adults 18 and older when used with a reduced-calorie, low-fat diet and exercise program.

Most-Reported Side Effects for Orlistat

From FAERS, the FDA’s public side-effect reporting system (25,755 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Rectal discharge 2,434 reports
Gastrointestinal disorder 2,186 reports
Constipation 1,991 reports
Diarrhea 1,960 reports
Weight increased 1,944 reports
See full Orlistat drug information
Keep checking

Other Drugs & Glucosamine

Browse every other medication we’ve checked against Glucosamine — both the ones with a known interaction and the ones without. Select any drug for the full detail.

2Major
13Moderate
155Minor
2,659No known interaction
Major

2 interactions

Moderate

13 interactions

Minor

155 interactions

Showing 60 of 155 minor interactions — see all 155 on the Glucosamine page.

No interaction 2,659 drugs checked — show the list
Evidence & sources

Glucosamine References

The 58 references that drive our Glucosamine monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  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

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Glucosamine and Orlistat Together: Common Questions

Is it safe to take Glucosamine with Orlistat?
We do not list a known interaction between Glucosamine and Orlistat. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Glucosamine and Orlistat have any of the same side effects?
Yes — our sources link each of them separately to 10 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Are Glucosamine and Orlistat used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Glucosamine in each. That is a conversation for your prescriber, especially if Orlistat is being adjusted to a target.
How was the Glucosamine and Orlistat combination checked?
Interactions in our licensed database are recorded against drug classes. Orlistat is filed under 2 classifications, and Glucosamine has documented interactions with 4 drug classes — none of Orlistat's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Glucosamine interact with any other medications?
Yes. Glucosamine has 170 documented drug interactions in our database — Orlistat is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Orlistat interact with any supplements?
Yes. Orlistat has documented interactions with 18 supplements in our database — Glucosamine is not one of them. The Orlistat interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Orlistat and Glucosamine?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.