Drug & supplement interaction

Daffodil + Glycerol Phenylbutyrate

Glycerol Phenylbutyrate brand name: Ravicti.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Daffodil 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

Daffodil 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 Daffodil 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 Daffodil 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.

Daffodil safety at a glance

Daffodil overall Avoid All parts of the daffodil are toxic and should not be eaten or used as a homemade supplement.
Pregnancy Likely Unsafe When used orally or topically; avoid using. Read the full pregnancy detail
Breastfeeding Likely Unsafe When used orally or topically; avoid using. 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 Daffodil? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Daffodil 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.

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

    Daffodil

    “Daffodil is generally regarded as unsafe for use. Any benefits of therapy may not outweigh the risk of toxicity.

    Serious Adverse Effects (Rare):

    Orally: Irritation and swelling of the mouth, tongue, and throat, and sudden onset of vomiting, diarrhea, and abdominal pain. Large doses have also been reported to cause blurred vision, coma, convulsions, dizziness, headache, hypotension, salivation, sweating, and tremors.”

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

    “Orally, daffodil can cause irritation and swelling of the mouth, tongue, and throat, as well as sudden onset of vomiting, diarrhea, and abdominal pain. Vomiting and diarrhea often limit the progression of symptoms, and adults typically recover within 3-4 hours. Large doses of daffodil can cause toxicity, including excessive salivation (18,19,101223).”

    Daffodil · Natural Medicines adverse-effect record, reported in diarrhea.

    3 sources cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    2. 19. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
    3. 101223. Matulkova P, Gobin M, Evans M, et al. Gastro-intestinal poisoning due to consumption of daffodils mistaken for vegetables at commercial markets, Bristol, United Kingdom. Clin Toxicol (Phila) 2012;50(8):788-90. doi: 10.3109/15563650.2012.718350. 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 ›

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

    Daffodil

    “Orally, large doses of daffodil can cause toxicity, including dizziness, headache, tremors, convulsions, and coma.”

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

    1 source cited
    1. 101223. Matulkova P, Gobin M, Evans M, et al. Gastro-intestinal poisoning due to consumption of daffodils mistaken for vegetables at commercial markets, Bristol, United Kingdom. Clin Toxicol (Phila) 2012;50(8):788-90. doi: 10.3109/15563650.2012.718350. 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 ›

  • A skin rash Additional detail

    Daffodil

    “Topically, skin contact with any part of the daffodil plant can cause dermatitis, sometimes referred to as "daffodil itch" or "lily rash" (18,5004,5005).

    Orally, large doses of daffodil can cause toxicity, including excessive sweating.”

    Daffodil · Natural Medicines adverse-effect record, reported in dermatitis.

    4 sources cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    2. 5004. Bruynzeel DP. Bulb dermatitis. Dermatological problems in the flower bulb industries. Contact Dermatitis 1997;37:70-7.
    3. 5005. Bruynzeel DP, de Boer EM, Brouwer EJ, et al. Dermatitis in bulb growers. Contact Dermatitis 1993;29:11-5. PubMed
    4. 101223. Matulkova P, Gobin M, Evans M, et al. Gastro-intestinal poisoning due to consumption of daffodils mistaken for vegetables at commercial markets, Bristol, United Kingdom. Clin Toxicol (Phila) 2012;50(8):788-90. doi: 10.3109/15563650.2012.718350. PubMed

    Glycerol Phenylbutyrate

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

Reported for Daffodil but not commonly for Glycerol Phenylbutyrate: sweating, blurred vision, seizures and low blood pressure.

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

Daffodil in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Unsafe

When used orally or topically; avoid using.

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 — Daffodil Should Not Break It

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

How much people look this up

Where Daffodil 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 Daffodil
Top half

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

29 days ago today
Medication Glycerol Phenylbutyrate
Top 25%

#287 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 Daffodil reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Daffodil 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 Daffodil

What is Daffodil?

  • Traditional anti-inflammatory remedy
  • Folk use for tumors and skin growths
  • Source of galantamine for memory/Alzheimer's
  • Antimicrobial folk use
  • Topical traditional remedies

Daffodil is a beautiful but toxic plant that contains alkaloids, including the one used to make the Alzheimer's drug galantamine. It is not safe to take as a homemade supplement, and all parts of the plant—especially the bulb—can cause serious poisoning if eaten. Leave any medicinal use to standardized, regulated medications prescribed by a doctor.

Narcissus pseudonarcissus · Amaryllidaceae · Bulb, flower, and leaves (source of certain alkaloids) · Not commonly available as a consumer supplement; the plant is the source of the prescription drug galantamine

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

Daffodil: dosing

There is no safe established dose of daffodil as a supplement, and it should not be taken by mouth. Because the whole plant is toxic, no amount can be recommended for self-treatment.The only proven medical use linked to this plant is the prescription drug galantamine, which is manufactured to a precise, standardized dose and must be prescribed and monitored by a healthcare provider.

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

Read the full Daffodil 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 & Daffodil

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

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

Daffodil References

The 5 references that drive our Daffodil 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. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  2. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  3. Bruynzeel DP. Bulb dermatitis. Dermatological problems in the flower bulb industries. Contact Dermatitis 1997;37:70-7.
  4. Bruynzeel DP, de Boer EM, Brouwer EJ, et al. Dermatitis in bulb growers. Contact Dermatitis 1993;29:11-5. PubMed
  5. Matulkova P, Gobin M, Evans M, et al. Gastro-intestinal poisoning due to consumption of daffodils mistaken for vegetables at commercial markets, Bristol, United Kingdom. Clin Toxicol (Phila) 2012;50(8):788-90. doi: 10.3109/15563650.2012.718350. 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 Daffodil and Glycerol Phenylbutyrate Together: Common Questions

Is it safe to take Daffodil with Glycerol Phenylbutyrate?
We do not list a known interaction between Daffodil 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 Daffodil and Glycerol Phenylbutyrate have any of the same side effects?
Yes — our sources link each of them separately to 6 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 Daffodil 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 Daffodil 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.
Does Glycerol Phenylbutyrate interact with any supplements?
Yes. Glycerol Phenylbutyrate has documented interactions with 17 supplements in our database — Daffodil 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 Daffodil?

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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.