Lysine + Glycerol Phenylbutyrate
Glycerol Phenylbutyrate brand name: Ravicti.
We found no known interaction between Lysine 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.
Lysine 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 Lysine 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.
Lysine safety at a glance
Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
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. Lysine has documented interactions with 1 drug class — the most serious being 5-ht4 agonists (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.
Lysine Does Interact With Other Medications
Lysine has 1 minor known drug interaction in our database — Glycerol Phenylbutyrate isn’t one of them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Lysine
We haven’t checked that one against Lysine yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Lysine. Pick one to open its full report.
Some Glycerol Phenylbutyrate Products Have a Food Rule — Lysine Should Not Break It
At least one FDA label for a product containing Glycerol Phenylbutyrate says to take it with food. If you take Lysine 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.
See Every Supplement That Interacts With Glycerol Phenylbutyrate
This page covers Lysine 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
Taking Lysine as Part of a Dietary Supplement Product? Check It for Interactions
We hold 3,540 real supplement products containing Lysine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Lysine. Even though Lysine 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:
Where Lysine 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.
#74 of 1,452 supplements looked up here in the last 7 days
#254 of 2,830 medications looked up here in the last 7 days
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 Lysine reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 27, 2026. The Lysine 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.
About Lysine
What is Lysine?
- Cold sores (herpes labialis)
- Genital herpes outbreaks
- Supporting protein and collagen formation
- Calcium absorption support
- General nutritional supplement
Lysine is an essential amino acid your body cannot make on its own, so it must come from food or supplements. People most often take extra lysine to try to prevent or shorten cold sores, but the evidence is mixed and far from conclusive. For most healthy people who eat enough protein, supplements are likely unnecessary, but they are generally considered low-risk at typical doses.
Amino acid (L-lysine) · Tablets, capsules, powder, topical creams (often combined with other ingredients)
An interaction check asks whether these two react with each other — it does not ask whether Lysine is a good idea for someone in your situation. Here is what our Lysine record says about it on its own.
Lysine: dosing
There is no single official supplement dose of lysine for any health condition, and a truly standardized dose has not been established for uses like cold sores. Products vary widely in how much they contain.The best approach is to follow the directions on the product label and not exceed the recommended amount.
From our Lysine monograph — the full record covers uses, side effects and every documented interaction.
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.
Other Drugs & Lysine
Browse every other medication we’ve checked against Lysine — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
1 interaction
No interaction 2,828 drugs checked — show the list
We also checked Lysine against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Amlodipine ›
- Levothyroxine ›
- Methylphenidate ›
- Warfarin ›
- Abemaciclib ›
- Ivermectin ›
- Testosterone ›
- Sertraline ›
- Acetaminophen ›
- Losartan Potassium ›
- Aspirin ›
- Rosuvastatin ›
- Metoprolol ›
- Escitalopram ›
- Clopidogrel ›
- Rivaroxaban ›
- Atorvastatin ›
- Methamphetamine ›
- Tirzepatide ›
- Warfarin Sodium ›
- Isotretinoin ›
- Ibuprofen ›
- Docusate ›
- Sumatriptan ›
- Valacyclovir ›
- Tadalafil ›
- Hydroxyurea ›
- Amlodipine Besylate ›
- Prednisone ›
- Semaglutide ›
- Metformin ›
- Lisdexamfetamine ›
- Amitriptyline ›
- Propranolol ›
- Amphetamine ›
- Methotrexate ›
- Lisinopril ›
- Amoxicillin ›
- Bupropion ›
- Levothyroxine, Liothyronine ›
- Fluoxetine ›
- Doxycycline ›
- Bendamustine ›
- Azithromycin ›
- Pregabalin ›
- Lamotrigine ›
- Acyclovir ›
- Gabapentin ›
- Dextroamphetamine ›
- Naproxen ›
- Quetiapine ›
- Clonazepam ›
- Buspirone ›
- Omeprazole ›
- Duloxetine ›
- Acetaminophen, Codeine ›
- Letrozole ›
- Citalopram ›
- Methylene Blue ›
Showing the 60 most looked-up of 2,828 medications checked with no known interaction — see the full Lysine list.
Lysine References
The 7 references that drive our Lysine 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.
- Thein DJ, Hurt WC. Lysine as a prophylactic agent in the treatment of recurrent herpes simplex labialis. Oral Surg Oral Med Oral Pathol 1984;58:659-66. PubMed
- McCune MA, Perry HO, Muller SA, O'Fallon WM. Treatment of recurrent herpes simplex infections with L-lysine monohydrochloride. Cutis 1984;34:366-73.
- DiGiovanna JJ, Blank H. Failure of lysine in frequently recurrent herpes simplex infection. Treatment and prophylaxis. Arch Dermatol 1984;120:48-51. DOI
- Milman N, Scheibel J, Jessen O. Lysine prophylaxis in recurrent herpes simplex labialis: a double-blind, controlled crossover study. Acta Derm Venereol 1980;60:85-7.
- Griffith RS, Walsh DE, Myrmel KH, et al. Success of L-lysine therapy in frequently recurrent herpes simplex infection. Treatment and prophylaxis. Dermatologica 1987;175:183-90. DOI
- Lo JC, Chertow GM, Rennke H, Seifter JL. Fanconi's syndrome and tubulointerstitial nephritis in association with L-lysine ingestion. Am J Kidney Dis 1996;28:614-7. PubMed
- Smriga M, Torii K. L-Lysine acts like a partial serotonin receptor 4 antagonist and inhibits serotonin-mediated intestinal pathologies and anxiety in rats. Proc Natl Acad Sci U S A. 2003 Dec 23;100(26):15370-5.
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.
Taking Lysine and Glycerol Phenylbutyrate Together: Common Questions
Is it safe to take Lysine with Glycerol Phenylbutyrate?
Do Lysine and Glycerol Phenylbutyrate have any of the same side effects?
Should I take Lysine and Glycerol Phenylbutyrate at the same time of day?
How was the Lysine and Glycerol Phenylbutyrate combination checked?
Does Lysine interact with any other medications?
Does Glycerol Phenylbutyrate interact with any supplements?
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.