Drug & supplement interaction

Noni + Fosphenytoin

Fosphenytoin brand name: Cerebyx.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Fosphenytoin falls into 2 drug categories that Noni can interact with; the most serious is rated moderate. Theoretically, taking noni with hepatotoxic drugs might increase the risk of liver damage.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Noni and Fosphenytoin

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Noni interacts with whole categories of medication. Fosphenytoin falls into 2 of those categories, so it can interact with Noni in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

HEPATOTOXIC DRUGS

1 of 2

Why this applies to Fosphenytoin

Fosphenytoin falls under HEPATOTOXIC DRUGS — the group Noni interacts with.

Theoretically, taking noni with hepatotoxic drugs might increase the risk of liver damage.
There is concern that noni might cause hepatotoxicity in some patients. Advise patients against combining noni with potentially hepatotoxic drugs.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the thing to know about pairing noni with fosphenytoin (Cerebyx). This isn't about noni changing how much seizure medicine is in your system. The concern is simpler: both can be hard on the liver. Fosphenytoin, like the phenytoin it turns into, can occasionally stress the liver, and there are scattered reports of noni juice doing the same. Stacking two things that lean on the liver may raise that risk.

To be fair, this is theoretical and based only on anecdotal reports, so I don't want to alarm you. Still, watch for signs like yellowing eyes or skin, dark urine, belly pain, or unusual tiredness. Please loop in your doctor or pharmacist before adding noni, since they may want to keep an eye on your liver.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Millonig G, Stadlmann S, Vogel W. Herbal hepatotoxicity: acute hepatitis caused by a Noni preparation (Morinda citrifolia). Eur J Gastroenterol Hepatol 2005;17:445-7. PubMed
  2. Stadlbauer V, Fickert P, Lackner C, et al. Hepatotoxicity of NONI juice: report of two cases. World J Gastroenterol 2005;11:4758-60. PubMed
  3. Yuce B, Gulberg V, Diebold J, Gerbes AL. Hepatitis induced by noni juice from morinda citrifolia: a rare cause of hepatotoxicity or the tip of the iceberg? Digestion 2006;73:167-70.
Moderate

PHENYTOIN (Dilantin)

2 of 2
Theoretically, taking noni fruit juice concomitantly with phenytoin may lower phenytoin levels and increase the risk of seizures.
In one case report, an adult taking phenytoin for partial seizures experienced low serum phenytoin levels while taking noni juice 90-200 mL daily. Serum phenytoin levels increased after decreasing noni juice consumption; similarly, serum phenytoin levels decreased after increasing noni juice consumption. Some researchers believe noni juice may induce cytochrome P450 2C9 enzymes, which would decrease phenytoin levels, but this has not been well studied. Patients may need additional monitoring when starting or stopping noni juice supplementation.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the thing to keep in mind: once fosphenytoin (Cerebyx) is in your body, it converts into phenytoin, the same medicine as Dilantin. So the noni-phenytoin concern applies here too. The worry is that noni juice may speed up the liver enzyme (CYP2C9) that clears phenytoin, which could lower your phenytoin levels. If your level drops, your seizures may not be as well controlled, which is a serious problem with a seizure medicine.

I want to be honest about the strength of this: it comes from a single case report and is largely theoretical, so it's not well proven. Still, phenytoin is a finicky drug where small changes matter. Please don't start or stop noni on your own. Talk with your doctor or pharmacist first, since you may need a level check.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Yu-Chan Kang, Ming-Hong Chen, Shung-Lon Lai. Potentially Unsafe Herb-drug Interactions Between a Commercial Product of Noni Juice and Phenytoin- A Case Report. Acta Neurol Taiwan. 2015 Jun;24(2):43-6.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Noni Also Interacts With Other Medications

Noni has 540 moderate, 1 minor known drug interactions in our database — the Fosphenytoin one above is among them. If you take anything else, check it against the full list below.

Moderate 540 Minor 1 No known interaction 2,289 (incl. Fosphenytoin)
Taking anything else?

Check Another of Your Medications Against Noni

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

Everything else you take

See Every Supplement That Interacts With Fosphenytoin

This page covers Noni only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fosphenytoin page lists 205 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 14 major · 172 moderate · 19 minor.

From our pharmacist’s overview on the Fosphenytoin page

“St. John's wort is the entry I would flag first with fosphenytoin (Cerebyx).”

Reviewed by 2 · Jul 18, 2026

Open the Fosphenytoin interaction page

One more smart check

Taking Noni as Part of a Dietary Supplement Product? Check It for Interactions

We hold 727 real supplement products containing Noni, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Noni. Your product may carry other ingredients that interact with Fosphenytoin too, on top of Noni — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Noni and Fosphenytoin 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 Noni
Top 25%

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

29 days ago today
Medication Fosphenytoin
Steady interest

#2,113 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.

Supplement

About Noni

What is Noni?

Noni
  • General wellness and energy
  • Inflammation and joint pain
  • Immune support
  • High blood pressure
  • Skin and wound care
  • Digestive complaints

Noni is a tropical fruit used widely in folk medicine and sold mostly as a juice or supplement, but solid human evidence for its many claimed benefits is limited. While moderate juice intake is generally well tolerated, there are rare reports of liver problems, and it should be avoided in pregnancy and breastfeeding. Talk with your pharmacist or doctor before using it, especially if you have kidney or liver disease.

Read the full Noni monograph & all interactions
Medication

About Fosphenytoin Injection

What Is Fosphenytoin Injection Used For?

Brand name: Cerebyx

Fosphenytoin injection is used to treat generalized tonic-clonic status epilepticus (a prolonged, life-threatening seizure emergency) and to prevent or treat seizures that occur during or after brain surgery. It is given by intravenous (IV) or intramuscular (IM) injection in a hospital or clinical setting.

It can also be used short-term as a substitute for oral phenytoin when a patient cannot take medicine by mouth. This use is temporary — as soon as oral phenytoin is possible again, it should replace the injection.

See full Fosphenytoin Injection drug information
Keep checking

Other Drugs & Noni

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

0Major
540Moderate
1Minor
2,288No known interaction
540 Moderate 1 Minor 2,288 No interaction
Moderate

540 interactions

Showing 60 of 540 moderate interactions — see all 540 on the Noni page.

Minor

1 interaction

No interaction 2,288 drugs checked — show the list

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

Showing the 60 most looked-up of 2,288 medications checked with no known interaction — see the full Noni list.

See the full Noni interactions page
See every supplement checked against Fosphenytoin, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Noni monograph › Uses, safety, and every drug interaction in one place Fosphenytoin supplement interactions › Every supplement checked against Fosphenytoin, ranked by severity Fosphenytoin Injection drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Noni and Fosphenytoin Together: Common Questions

Can you take Noni with Fosphenytoin?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Noni and Fosphenytoin?
Fosphenytoin belongs to more than one drug category, and Noni interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Noni and Fosphenytoin interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Fosphenytoin and Noni?

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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.