Eastern Hemlock + Glycerol Phenylbutyrate
Glycerol Phenylbutyrate brand name: Ravicti.
We found no known interaction between Eastern Hemlock 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.
Eastern Hemlock 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 Eastern Hemlock 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.
Worth understanding: our licensed dataset holds no drug-interaction record for Eastern Hemlock at all — not against Glycerol Phenylbutyrate, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.
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.
Eastern Hemlock safety at a glance
Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
Some Glycerol Phenylbutyrate Products Have a Food Rule — Eastern Hemlock Should Not Break It
At least one FDA label for a product containing Glycerol Phenylbutyrate says to take it with food. If you take Eastern Hemlock 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 Eastern Hemlock 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
Where Eastern Hemlock 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.
#1,042 of 1,452 supplements looked up here in the last 7 days
#260 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 Eastern Hemlock reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 27, 2026. The Eastern Hemlock 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 Eastern Hemlock
What is Eastern Hemlock?
- Coughs and colds
- Sore throat
- Wound care
- Vitamin C source (needle tea)
- Aches and pains (topical)
Eastern Hemlock is an evergreen conifer tree (Tsuga canadensis) traditionally used by Native Americans and early settlers for coughs, sore throats, and as a vitamin C-rich tea. There is very little modern scientific evidence to support any of these uses, and it should not be confused with poison hemlock. Talk to a pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.
Tsuga canadensis · Pinaceae · Inner bark, needles (leaves), young twigs, and resin · Tea, tincture, essential oil, salve, and bark extract
An interaction check asks whether these two react with each other — it does not ask whether Eastern Hemlock is a good idea for someone in your situation. Here is what our Eastern Hemlock record says about it on its own.
Eastern Hemlock: dosing
There is no established or standardized dose for Eastern Hemlock. It has not been studied enough to know a safe and effective amount for any condition.If you choose to use a commercial product, follow the directions on the label exactly and do not exceed them. Essential oils should be used only as directed for external use and kept away from the eyes, mouth, and children.
From our Eastern Hemlock 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 & Eastern Hemlock
Browse every other medication we’ve checked against Eastern Hemlock — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
No interaction 2,829 drugs checked — show the list
We also checked Eastern Hemlock against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Abemaciclib ›
- Ivermectin ›
- Sertraline ›
- Testosterone ›
- Acetaminophen ›
- Losartan Potassium ›
- Aspirin ›
- Rosuvastatin ›
- Metoprolol ›
- Escitalopram ›
- Clopidogrel ›
- Rivaroxaban ›
- Atorvastatin ›
- Methamphetamine ›
- Tirzepatide ›
- Ibuprofen ›
- Docusate ›
- Warfarin Sodium ›
- Tadalafil ›
- Sumatriptan ›
- Valacyclovir ›
- Isotretinoin ›
- Hydroxyurea ›
- Prednisone ›
- Semaglutide ›
- Metformin ›
- Lisdexamfetamine ›
- Propranolol ›
- Amlodipine Besylate ›
- Amitriptyline ›
- Methotrexate ›
- Amphetamine ›
- Lisinopril ›
- Amoxicillin ›
- Bupropion ›
- Fluoxetine ›
- Bendamustine ›
- Doxycycline ›
- Pregabalin ›
- Azithromycin ›
- Levothyroxine, Liothyronine ›
- Lamotrigine ›
- Acyclovir ›
- Gabapentin ›
- Dextroamphetamine ›
- Naproxen ›
- Quetiapine ›
- Clonazepam ›
- Omeprazole ›
- Buspirone ›
- Duloxetine ›
- Letrozole ›
- Acetaminophen, Codeine ›
- Citalopram ›
- Methylene Blue ›
Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Eastern Hemlock list.
Eastern Hemlock References
The 2 references that drive our Eastern Hemlock 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.
- McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
- Mitchell, J. C. Patch test results - screening set and plants. Contact Dermatitis Newsletter 1970;8:177.
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 Eastern Hemlock and Glycerol Phenylbutyrate Together: Common Questions
Is it safe to take Eastern Hemlock with Glycerol Phenylbutyrate?
Do Eastern Hemlock and Glycerol Phenylbutyrate have any of the same side effects?
Should I take Eastern Hemlock and Glycerol Phenylbutyrate at the same time of day?
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.