Drug & supplement interaction

Ephedra + Glycerol Phenylbutyrate

Glycerol Phenylbutyrate brand name: Ravicti.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 27, 2026

The bottom line No known interaction

We found no known interaction between Ephedra 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

Ephedra 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 Ephedra 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.

Ephedra safety at a glance

Ephedra overall Avoid Banned in dietary supplements in the U.S. due to serious cardiovascular risks, including death.

Pregnancy Likely Unsafe When used orally. Ephedra has been linked to several cases of severe side effects. Read the full pregnancy detail

Breastfeeding Likely Unsafe When used orally. Ephedra has been linked to several cases of severe side effects. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Glycerol Phenylbutyrate and Ephedra? 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. Ephedra has documented interactions with 11 drug classes — the most serious being methylxanthines (major), qt interval-prolonging drugs (major) and stimulant drugs (major) — 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

Ephedra Does Interact With Other Medications

Ephedra has 337 major, 496 moderate 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.

Major 337 Moderate 496 No known interaction 1,997 (incl. Glycerol Phenylbutyrate)

Taking anything else?

Check Another of Your Medications Against Ephedra

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

What to actually watch for

No Interaction Found — But Data Suggests Ephedra 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 / Reduced appetite / Vomiting reported in 12.2% of FDA reports for Glycerol Phenylbutyrate Additional detail
Ephedra

“Orally, ephedra is frequently associated with adverse reactions and is banned in the US. In some cases, adverse effects can be severe or life-threatening. Large studies looking at the safety of ephedra have not been performed. Since most of the adverse effect data are from case reports, it is impossible to determine the overall incidence of these adverse effects.”

Ephedra · Natural Medicines adverse-effect record, reported in anorexia.
“The use of ephedra causes a 2.2- to 3.6-fold increase in the risk of developing psychiatric, autonomic, or gastrointestinal (GI) symptoms and cardiac palpitations. Orally and intravenously, ephedra and ephedrine most commonly cause dry mouth, anorexia, nausea, vomiting, heartburn, abdominal discomfort, and changes in stool consistency.”

Ephedra · Natural Medicines adverse-effect record, reported in anorexia.
6 sources cited

9740. Shekelle PG, Hardy ML, Morton SC, et al. Efficacy and safety of ephedra and ephedrine for weight loss and athletic performance: a meta-analysis. JAMA 2003;289:1537-45.. PubMed

48878. Shekelle P, Morton, S, Maglione, M, and et al. Ephedra and Ephedrine for Weight Loss and Athletic Performance Enhancement: Clinical Efficacy and Side Effects. Evidence Report/Technology Assessment No. 76 (Prepared by Southern California Evidence-based Pr

1276. Doyle H, Kargin M. Herbal stimulant containing ephedrine has also caused psychosis. BMJ 1996;313:756. PubMed

3719. Boozer CN, Nasser JA, Heymsfield SB, et al. An herbal supplement containing Ma Huang-Guarana for weight loss: a randomized, double-blind trial. Int J Obes Relat Metab Disord 2001;25:316-24. PubMed

6008. Gurley BJ, Gardner SF, Hubbard MA. Content versus label claims in ephedra-containing dietary supplements. Am J Health Syst Pharm 2000;57:963-9. PubMed

6486. Haller CA, Benowitz NL. Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids. N Engl J Med 2000;343:1833-8. 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 ›
Mood changes or irritability / Anxiety or restlessness Additional detail
Ephedra
“The use of ephedra causes a 2.2- to 3.6-fold increase in the risk of developing psychiatric, autonomic, or gastrointestinal (GI) symptoms and cardiac palpitations. Ephedra most commonly causes anxiety, irritability, personality changes, difficulty concentrating, and insomnia.

Cases of ephedrine-induced psychiatric complications include mania, psychosis, and hallucinations.”

Ephedra · Natural Medicines adverse-effect record, reported in anxiety.
6 sources cited

9740. Shekelle PG, Hardy ML, Morton SC, et al. Efficacy and safety of ephedra and ephedrine for weight loss and athletic performance: a meta-analysis. JAMA 2003;289:1537-45.. PubMed

48878. Shekelle P, Morton, S, Maglione, M, and et al. Ephedra and Ephedrine for Weight Loss and Athletic Performance Enhancement: Clinical Efficacy and Side Effects. Evidence Report/Technology Assessment No. 76 (Prepared by Southern California Evidence-based Pr

1276. Doyle H, Kargin M. Herbal stimulant containing ephedrine has also caused psychosis. BMJ 1996;313:756. PubMed

3719. Boozer CN, Nasser JA, Heymsfield SB, et al. An herbal supplement containing Ma Huang-Guarana for weight loss: a randomized, double-blind trial. Int J Obes Relat Metab Disord 2001;25:316-24. PubMed

6008. Gurley BJ, Gardner SF, Hubbard MA. Content versus label claims in ephedra-containing dietary supplements. Am J Health Syst Pharm 2000;57:963-9. PubMed

6486. Haller CA, Benowitz NL. Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids. N Engl J Med 2000;343:1833-8. PubMed
Glycerol Phenylbutyrate

Listed in the ADVERSE REACTIONS section of the FDA label for Glycerol Phenylbutyrate. Read the label on DailyMed ›
Stomach upset / Stomach pain / Diarrhea Additional detail

Ephedra

Recorded for Ephedra in the same Natural Medicines adverse-effect record shown under Heartburn / Reduced appetite / Vomiting above.

Glycerol Phenylbutyrate

Listed in the ADVERSE REACTIONS section of the FDA label for Glycerol Phenylbutyrate. Read the label on DailyMed ›
Dizziness / Headache reported in 4.9% of FDA reports for Glycerol Phenylbutyrate Additional detail
Ephedra
“The use of ephedra causes a 2.2- to 3.6-fold increase in the risk of developing psychiatric, autonomic, or gastrointestinal (GI) symptoms and cardiac palpitations. Ephedra most commonly causes dizziness, restlessness, anxiety, irritability, personality changes, difficulty concentrating, insomnia, and headache.

Ephedra can cause seizures in otherwise healthy people, as well as in people with underlying seizure disorde…”

Ephedra · Natural Medicines adverse-effect record, reported in anxiety.
6 sources cited

9740. Shekelle PG, Hardy ML, Morton SC, et al. Efficacy and safety of ephedra and ephedrine for weight loss and athletic performance: a meta-analysis. JAMA 2003;289:1537-45.. PubMed

48878. Shekelle P, Morton, S, Maglione, M, and et al. Ephedra and Ephedrine for Weight Loss and Athletic Performance Enhancement: Clinical Efficacy and Side Effects. Evidence Report/Technology Assessment No. 76 (Prepared by Southern California Evidence-based Pr

1276. Doyle H, Kargin M. Herbal stimulant containing ephedrine has also caused psychosis. BMJ 1996;313:756. PubMed

3719. Boozer CN, Nasser JA, Heymsfield SB, et al. An herbal supplement containing Ma Huang-Guarana for weight loss: a randomized, double-blind trial. Int J Obes Relat Metab Disord 2001;25:316-24. PubMed

6008. Gurley BJ, Gardner SF, Hubbard MA. Content versus label claims in ephedra-containing dietary supplements. Am J Health Syst Pharm 2000;57:963-9. PubMed

6486. Haller CA, Benowitz NL. Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids. N Engl J Med 2000;343:1833-8. 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 ›

Showing the 10 most notable of 11 shared effects — ranked by how unusual each one is, not just whether both lists mention it.

Reported for Ephedra but not commonly for Glycerol Phenylbutyrate: a stroke or mini-stroke, trouble concentrating, fainting and a heart attack.

Effects for Glycerol Phenylbutyrate come from the ADVERSE REACTIONS section of its FDA label; effects for Ephedra 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.

Special populations

Ephedra in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Unsafe

When used orally. Ephedra has been linked to several cases of severe side effects.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

How to take them

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

At least one FDA label for a product containing Glycerol Phenylbutyrate says to take it with food. If you take Ephedra 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.

Everything else you take

See Every Supplement That Interacts With Glycerol Phenylbutyrate

This page covers Ephedra 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 Ephedra as Part of a Dietary Supplement Product? Check It for Interactions

We hold 37 real supplement products containing Ephedra, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Ephedra. Even though Ephedra 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 Ephedra 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 Ephedra

Top half

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

29 days ago today

Medication Glycerol Phenylbutyrate

Top 10%

#268 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 Ephedra reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 27, 2026. The Ephedra 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 Dr. Brian Staiger, PharmD, BCPS.

Supplement

About Ephedra

What is Ephedra?

Weight loss
Nasal and sinus congestion
Asthma and breathing problems
Boosting energy and athletic performance
Allergies

Ephedra (ma huang) contains powerful stimulants like ephedrine that affect the heart and nervous system. Because it has been linked to serious harms including high blood pressure, stroke, and death, it is banned for use in dietary supplements in the U.S. and many other countries. We do not recommend using ephedra-containing supplements; talk to your pharmacist or doctor about safer, approved options.

Ephedra sinica · Ephedraceae · Dried stems and branches (aerial parts) · Historically: capsules, tablets, teas, and tinctures (now banned in dietary supplements in many countries)

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

Ephedra: dosing

There is no safe, recommended supplement dose for ephedra. It is banned in dietary supplements in the U.S. and many other countries, so we cannot and do not provide a dose.Some regulated, FDA-approved over-the-counter medicines (for example certain asthma products) contain ephedrine in carefully controlled amounts and come with specific label directions.

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

Read the full Ephedra 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.

Most-Reported Side Effects for Glycerol Phenylbutyrate

From FAERS, the FDA’s public side-effect reporting system (1,358 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Ammonia increased 197 reports

Vomiting 165 reports

Hyperammonaemia 158 reports

Decreased appetite 104 reports

Nausea 74 reports

See full Glycerol Phenylbutyrate drug information

Keep checking

Other Drugs & Ephedra

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

337Major

496Moderate

0Minor

1,996No known interaction

337 Major 496 Moderate 1,996 No interaction

Major

337 interactions

Showing 60 of 337 major interactions — see all 337 on the Ephedra page.

Moderate

496 interactions

Showing 60 of 496 moderate interactions — see all 496 on the Ephedra page.

No interaction 1,996 drugs checked — show the list

We also checked Ephedra against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 1,996 medications checked with no known interaction — see the full Ephedra list.

See the full Ephedra interactions page

See every supplement checked against Glycerol Phenylbutyrate, ranked by severity

Evidence & sources

Ephedra References

The 87 references that drive our Ephedra 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.

Okada S, Rohan PJ, Miller FW, et al. Myopathies following ingestion of special nutritional products. Arthritis Rheum 1996;39:349.
Zaacks SM, Klein L, Tan CD, et al. Hypersensitivity myocarditis associated with ephedra use. J Toxicol Clin Toxicol 1999;37:485-9. PubMed
Powell T, Hsu FF, Turk J, Hruska K. Ma-huang strikes again: ephedrine nephrolithiasis. Am J Kidney Dis 1998;32:153-9. PubMed
Nadir A, Agrawal S, King PD, Marshall JB. Acute hepatitis associated with the use of a Chinese herbal product, ma-huang. Am J Gastroenterol 1996;91:1436-8.
Theoharides TC. Sudden death of a healthy college student related to ephedrine toxicity from a ma-huang containing drink. J Clin Psychopharmacol 1997;17:437-9. PubMed
Vahedi K, Domingo V, Amarenco P, Bousser MG. Ischemic stroke in a sportsman who consumed MaHuang extract and creatine monohydrate for bodybuilding. J Neurol Neurosurg Psychiatr 2000;68:112-3.
Doyle H, Kargin M. Herbal stimulant containing ephedrine has also caused psychosis. BMJ 1996;313:756. PubMed
FDA Takes Aim at Ephedra. The Washington Post. Available at: http://www.washingtonpost.com/archive/politics/2000/03/19/fda-takes-aim-at-ephedra/4ce534a7-d291-44ec-88a8-38e97ff27e3b/ (Accessed 19 March 2000).
FDA. Proposed rule: dietary supplements containing ephedrine alkaloids. Available at: www.verity.fda.gov (Accessed 25 January 2000).
Boozer CN, Nasser JA, Heymsfield SB, et al. An herbal supplement containing Ma Huang-Guarana for weight loss: a randomized, double-blind trial. Int J Obes Relat Metab Disord 2001;25:316-24. PubMed
Gurley BJ, Gardner SF, Hubbard MA. Content versus label claims in ephedra-containing dietary supplements. Am J Health Syst Pharm 2000;57:963-9. PubMed
White LM, Gardner SF, Gurley BJ, et al. Pharmacokinetics and Cardiovascular Effects of Ma-Huang (Ephedra sinica) in Normotensive Adults. J Clin Pharmacol 1997;37:116-22.
Haller CA, Benowitz NL. Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids. N Engl J Med 2000;343:1833-8. PubMed
Leikin JB, Klein L. Ephedra causes myocarditis. Clin Toxicol 2000;38:353-4.
Jacobs KM, Hirsch KA. Psychiatric complications of Ma-huang. Psychosomatics 2000;41:58-62. PubMed
Dulloo AG. Herbal simulation of ephedrine and caffeine in treatment of obesity. Int J Obes Relat Metab Disord 2002;26:590-2. PubMed
Samenuk D, Link MS, Homoud MK, et al. Adverse cardiovascular events temporally associated with ma huang, an herbal source of ephedrine. Mayo Clin Proc 2002;77:12-6. PubMed
Boozer CN, Daly PA, Homel P, et al. Herbal ephedra/caffeine for weight loss: a 6-month randomized safety and efficacy trial. Int J Obes Relat Metab Disord 2002;26:593-604. PubMed
Morgenstern LB, Viscoli CM, Kernan WN, et al. Use of Ephedra-containing products and risk for hemorrhagic stroke. Neurology 2003;60:132-5. .
Shekelle PG, Hardy ML, Morton SC, et al. Efficacy and safety of ephedra and ephedrine for weight loss and athletic performance: a meta-analysis. JAMA 2003;289:1537-45.. PubMed
Kalman D, Incledon T, Gaunaurd I, et al. An acute clinical trial evaluating the cardiovascular effects of an herbal ephedra-caffeine weight loss product in healthy overweight adults. Int J Obes 2002;26:1363-66.. PubMed
Schweinfurth J, Pribitkin E. Sudden hearing loss associated with ephedra use. Am J Health Syst Pharm 2003;60:375-7. PubMed
Kockler DR, McCarthy MW, Lawson CL. Seizure activity and unresponsiveness after hydroxycut ingestion. Pharmacotherapy 2001;21:647-51.. PubMed
Yates KM, O'Connor A, Horsley CA. "Herbal Ecstasy": a case series of adverse reactions. N Z Med J 2000;113:315-7..
Walton R, Manos GH. Psychosis related to ephedra-containing herbal supplement use. South Med J 2003;96:718-20.. PubMed
Jenkins DJ, Wesson V, Wolever TM, et al. Wholemeal versus wholegrain breads: proportion of whole or cracked grain and the glycaemic response. BMJ 1988;297:958-60. PubMed
McBride BF, Karapanos AK, Krudysz A, et al. Electrocardiographic and hemodynamic effects of a multicomponent dietary supplement containing ephedra and caffeine: a randomized controlled trial. JAMA 2004;291:216-21. PubMed
Brooks SM, Sholiton LJ, Werk EE Jr, Altenau P. The effects of ephedrine and theophylline on dexamethasone metabolism in bronchial asthma. J Clin Pharmacol 1977;17:308-18. PubMed
Gardner SF, Franks AM, Gurley BJ, et al. Effect of a multicomponent, ephedra-containing dietary supplement (Metabolife 356) on Holter monitoring and hemostatic parameters in healthy volunteers. Am J Cardiol 2003;91:1510-3, A9. PubMed
Haller CA, Jacob P 3rd, Benowitz NL. Enhanced stimulant and metabolic effects of combined ephedrine and caffeine. Clin Pharmacol Ther 2004;75:259-73.
Haller CA, Meier KH, Olson KR. Seizures reported in association with use of dietary supplements. Clin Toxicol (Phila) 2005;43:23-30. PubMed
Burke J, Seda G, Allen D, Knee TS. A case of severe exercise-induced rhabdomyolysis associated with a weight loss dietary supplement. Mil Med 2007;172:656-8. PubMed
Dawson, J. K., Earnshaw, S. M., and Graham, C. S. Dangerous monoamine oxidase inhibitor interactions are still occurring in the 1990s. J Accid.Emerg.Med 1995;12(1):49-51. PubMed
Weinberger M and Bronsky E. Interaction of ephedrine and theophylline. Clin Pharmacol Ther 1974;15(2):223. PubMed
Kernan, W. N., Viscoli, C. M., Brass, L. M., Broderick, J. P., Brott, T., Feldmann, E., Morgenstern, L. B., Wilterdink, J. L., and Horwitz, R. I. Phenylpropanolamine and the risk of hemorrhagic stroke. N.Engl.J Med 12-21-2000;343(25):1826-1832. PubMed
Jubiz, W. and Meikle, A. W. Alterations of glucocorticoid actions by other drugs and disease states. Drugs 1979;18(2):113-121. PubMed
Thomas, J. E., Munir, J. A., McIntyre, P. Z., and Ferguson, M. A. STEMI in a 24-year-old man after use of a synephrine-containing dietary supplement: a case report and review of the literature. Tex.Heart Inst.J 2009;36(6):586-590.
Cohen, P. A. and Ernst, E. Safety of herbal supplements: a guide for cardiologists. Cardiovasc.Ther 2010;28(4):246-253. PubMed
Astrup, A., Breum, L., Toubro, S., Hein, P., and Quaade, F. The effect and safety of an ephedrine/caffeine compound compared to ephedrine, caffeine and placebo in obese subjects on an energy restricted diet. A double blind trial. Int.J.Obes.Relat Metab D
Hackman, R. M., Havel, P. J., Schwartz, H. J., Rutledge, J. C., Watnik, M. R., Noceti, E. M., Stohs, S. J., Stern, J. S., and Keen, C. L. Multinutrient supplement containing ephedra and caffeine causes weight loss and improves metabolic risk factors in o
Hasani-Ranjbar, S., Nayebi, N., Larijani, B., and Abdollahi, M. A systematic review of the efficacy and safety of herbal medicines used in the treatment of obesity. World J Gastroenterol. 7-7-2009;15(25):3073-3085. PubMed
Lovstad, R. Z., Granhus, G., and Hetland, S. Bradycardia and asystolic cardiac arrest during spinal anaesthesia: a report of five cases. Acta Anaesthesiol.Scand 2000;44(1):48-52. PubMed
Ngan Kee, W. D., Khaw, K. S., Lee, B. B., Lau, T. K., and Gin, T. A dose-response study of prophylactic intravenous ephedrine for the prevention of hypotension during spinal anesthesia for cesarean delivery. Anesth.Analg. 2000;90(6):1390-1395. PubMed
Kurt, T. L. Hypersensitivity myocarditis with ephedra use. J Toxicol.Clin Toxicol. 2000;38(3):351.
Leikin, J. B. and Klein, L. Ephedra causes myocarditis. J Toxicol.Clin Toxicol. 2000;38(3):353-354.
du, Boisgueheneuc F., Lannuzel, A., Caparros-Lefebvre, D., and De Broucker, T. [Cerebral infarction in a patient consuming MaHuang extract and guarana]. Presse Med 2-3-2001;30(4):166-167.
Borum, M. L. Fulminant exacerbation of autoimmune hepatitis after the use of ma huang. Am J Gastroenterol. 2001;96(5):1654-1655. PubMed
Tormey, W. P. and Bruzzi, A. Acute psychosis due to the interaction of legal compounds--ephedra alkaloids in 'vigueur fit' tablets, caffeine in 'red bull' and alcohol. Med Sci Law 2001;41(4):331-336. PubMed
Traboulsi, A. S., Viswanathan, R., and Coplan, J. Suicide attempt after use of herbal diet pill. Am J Psychiatry 2002;159(2):318-319. PubMed
Schweinfurth, J. and Pribitkin, E. Sudden hearing loss associated with ephedra use. Am J Health Syst Pharm 2-15-2003;60(4):375-377. PubMed
Gardner, S. F., Franks, A. M., Gurley, B. J., Haller, C. A., Singh, B. K., and Mehta, J. L. Effect of a multicomponent, ephedra-containing dietary supplement (Metabolife 356) on Holter monitoring and hemostatic parameters in healthy volunteers. Am J Card PubMed
Karch, S. B. Use of Ephedra-containing products and risk for hemorrhagic stroke. Neurology 9-9-2003;61(5):724-725. PubMed
Chen-Scarabelli, C., Hughes, S. E., Landon, G., Rowley, P., Allebban, Z., Lawson, N., Saravolatz, L., Gardin, J., Latchman, D., and Scarabelli, T. M. A case of fatal ephedra intake associated with lipofuscin accumulation, caspase activation and cleavage
Moawad, F. J., Hartzell, J. D., Biega, T. J., and Lettieri, C. J. Transient blindness due to posterior reversible encephalopathy syndrome following ephedra overdose. South Med J 2006;99(5):511-514. PubMed
Stahl, C. E., Borlongan, C. V., Szerlip, M., and Szerlip, H. No pain, no gain--exercise-induced rhabdomyolysis associated with the performance enhancer herbal supplement ephedra. Med Sci Monit. 2006;12(9):CS81-CS84.
Caron, M. F., Dore, D. D., Min, B., Kluger, J., Boguk, I., and White, C. M. Electrocardiographic and blood pressure effects of the ephedra-containing TrimSpa thermogenic herbal compound in healthy volunteers. Pharmacotherapy 2006;26(9):1241-1246. PubMed
Vigano, M., Lampertico, P., and Colombo, M. Acute hepatitis following assumption of a herbal remedy. Eur.J.Gastroenterol.Hepatol. 2008;20(4):364-365. PubMed
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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 Ephedra and Glycerol Phenylbutyrate Together: Common Questions

Is it safe to take Ephedra with Glycerol Phenylbutyrate?

We do not list a known interaction between Ephedra 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 Ephedra 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 Ephedra 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 Ephedra 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 Ephedra and Glycerol Phenylbutyrate combination checked?

Interactions in our licensed database are recorded against drug classes. Glycerol Phenylbutyrate is filed under 1 classification, and Ephedra has documented interactions with 11 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 Ephedra interact with any other medications?

Yes. Ephedra has 833 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 — Ephedra 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

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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.