Drug & supplement interaction

Glucosamine + Glycerol Phenylbutyrate

Glycerol Phenylbutyrate brand name: Ravicti.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Glucosamine and Glycerol Phenylbutyrate 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 label for Glycerol Phenylbutyrate states a food rule worth keeping to, and 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 Glycerol Phenylbutyrate

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 Glycerol Phenylbutyrate 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 Glycerol Phenylbutyrate and Glucosamine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Glycerol Phenylbutyrate

Interactions in our licensed database are recorded against drug classes, not just single drug names. Glycerol Phenylbutyrate is filed under a single classification — 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 Glycerol Phenylbutyrate’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 — Glycerol Phenylbutyrate 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 Glycerol Phenylbutyrate 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.

  • Heartburn / Bloating or gas / Constipation / Diarrhea / Nausea reported in 5.4% of FDA reports for Glycerol Phenylbutyrate 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.

    “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

    Glycerol Phenylbutyrate

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

  • Stomach upset / Vomiting / Stomach pain reported in 12.2% of FDA reports for Glycerol Phenylbutyrate Additional detail

    Glucosamine

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

    Glycerol Phenylbutyrate

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

  • Headache reported in 4.9% of FDA reports for Glycerol Phenylbutyrate Additional detail

    Glucosamine

    “Orally, glucosamine has been reported to cause drowsiness and headache. Glucosamine plus chondroitin combination products that also contain manganese (e.g., CosaminDS) should always be taken according to product directions. When taken at doses slightly higher than the recommended dose, these products can sometimes supply greater than the tolerable upper limit (UL) for manganese which is 11 mg/day.”

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

    4 sources cited
    1. 2608. Barclay TS, Tsourounis C, McCart GM. Glucosamine. Ann Pharmacother 1998;32:574-9.
    2. 89561. 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
    3. 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
    4. 7135. 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.

    Glycerol Phenylbutyrate

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

  • A skin rash 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

    “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

    Glycerol Phenylbutyrate

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

Reported for Glucosamine but not commonly for Glycerol Phenylbutyrate: sun sensitivity, an allergic reaction, unsteadiness and liver problems.

Effects for Glycerol Phenylbutyrate 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 1,358 voluntary FDA FAERS reports for Glycerol Phenylbutyrate 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.

How to take them

Some Glycerol Phenylbutyrate Products Have a Food Rule — Glucosamine Should Not Break It

At least one FDA label for a product containing Glycerol Phenylbutyrate says to take it with food. If you take Glucosamine on an empty stomach out of habit, keep them separate — and take Glycerol Phenylbutyrate with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Glycerol Phenylbutyrate products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Instruct patients to take glycerol phenylbutyrate oral liquid with food or formula and to administer directly into the mouth via oral syringe.

From the Dosage and Administration section of the FDA label we read for Glycerol Phenylbutyrate — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

From our Q&A

Questions About Glucosamine or Glycerol Phenylbutyrate

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 Glycerol Phenylbutyrate, 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 Glycerol Phenylbutyrate

This page covers Glucosamine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Glycerol Phenylbutyrate page lists 17 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), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 7 moderate · 9 minor.

From our pharmacist’s overview on the Glycerol Phenylbutyrate page

“Ravicti (glycerol phenylbutyrate) pulls ammonia out of the blood in people with urea cycle disorders, so a dose that never gets absorbed is not a small problem, it can let ammonia climb toward dangerous levels. That is why this list deserves real attention even though it is short.”

Reviewed by 2 · Jul 18, 2026

Open the Glycerol Phenylbutyrate 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 Glycerol Phenylbutyrate, 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 Glycerol Phenylbutyrate 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%

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

29 days ago today
Medication Glycerol Phenylbutyrate
Top 10%

#171 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 27, 2026. The Glucosamine and Glycerol Phenylbutyrate 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 Glycerol Phenylbutyrate

What Is Glycerol Phenylbutyrate Used For?

Brand name: Ravicti

Glycerol phenylbutyrate oral liquid — available as the brand Ravicti and as a generic — is used for the long-term (chronic) management of urea cycle disorders (UCDs). UCDs are rare inherited conditions where the body cannot properly convert ammonia into urea, causing toxic ammonia levels to build up in the blood and brain.

It is used in patients whose ammonia cannot be controlled by a low-protein diet and/or amino acid supplements alone. It must always be used alongside dietary protein restriction and, in some cases, additional dietary supplements such as essential amino acids, arginine, or citrulline. It is not for treating a sudden, severe spike in ammonia (acute hyperammonemia), and its safety and effectiveness for N-acetylglutamate synthase (NAGS) deficiency have not been established.

See full Glycerol Phenylbutyrate 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 Glycerol Phenylbutyrate Together: Common Questions

Is it safe to take Glucosamine with Glycerol Phenylbutyrate?
We do not list a known interaction between Glucosamine and Glycerol Phenylbutyrate. 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 Glycerol Phenylbutyrate 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.
Should I take Glucosamine and Glycerol Phenylbutyrate at the same time of day?
At least one FDA label for a product containing Glycerol Phenylbutyrate says to take it with food. If you take Glucosamine on an empty stomach out of habit, keep them separate and take Glycerol Phenylbutyrate with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Glycerol Phenylbutyrate products can differ — so check the directions on your own box. This is about absorption, not an interaction.
How was the Glucosamine and Glycerol Phenylbutyrate combination checked?
Interactions in our licensed database are recorded against drug classes. Glycerol Phenylbutyrate is filed under 1 classification, and Glucosamine has documented interactions with 4 drug classes — none of Glycerol Phenylbutyrate'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 — Glycerol Phenylbutyrate 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 Glycerol Phenylbutyrate interact with any supplements?
Yes. Glycerol Phenylbutyrate has documented interactions with 17 supplements in our database — Glucosamine is not one of them. The Glycerol Phenylbutyrate 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 Glycerol Phenylbutyrate 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.