Drug & supplement interaction

Fo-ti + Lonafarnib

Lonafarnib brand name: Zokinvy.

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

Lonafarnib falls into 2 drug categories that Fo-ti can interact with; the most serious is rated moderate. Theoretically, fo-ti may increase the levels and clinical effects of drugs metabolized by CYP2C9.

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

Fo-ti and Lonafarnib

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

Why Are There 2 Interactions?

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

Moderate

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

1 of 2

Why this applies to Lonafarnib

Lonafarnib falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES — the group Fo-ti interacts with.

Theoretically, fo-ti may increase the levels and clinical effects of drugs metabolized by CYP2C9.
Animal and in vitro research suggests that fo-ti may inhibit CYP2C9. However, this interaction has not been reported in humans.
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 short version: lab and animal studies hint that Fo-ti might slow down an enzyme called CYP2C9, which is one of the pathways your body uses to clear Lonafarnib (Zokinvy). If that enzyme works more slowly, Lonafarnib could build up in your system. In theory, that might mean stronger effects and a higher chance of its usual side effects, like nausea, vomiting, diarrhea, poor appetite, fatigue, or changes in lab values.

I want to be honest about the strength of this, though. This is only seen in test-tube and animal research, and it has not been reported in real people. Lonafarnib is a serious medication for a rare condition, so before adding Fo-ti, please check with your doctor or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  2. Zhang Y, Ding T, Diao T, Deng M, Chen S. Effects of Polygonum multiflorum on the activity of cytochrome P450 isoforms in rats. Pharmazie 2015;70(1):47-54. DOI
  3. Xing Y, Yu Q, Zhou L, et al. Cytochrome P450-mediated herb-drug interaction (HDI) of Polygonum multiflorum Thunb. based on pharmacokinetic studies and in vitro inhibition assays. Phytomedicine 2023;112:154710. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

Lonafarnib also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, fo-ti might increase the levels and clinical effects of drugs metabolized by CYP3A4.
In vitro research suggests that fo-ti might inhibit CYP3A4. One in vitro study suggests that the degree of CYP3A4 inhibition may depend on the type of fo-ti extract (i.e., the raw plant leads to greater inhibition than extensively processed extracts). However, this evidence conflicts with animal research suggesting that fo-ti does not inhibit CYP3A4. This interaction has not been reported in humans.
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 gist with Zokinvy (lonafarnib): your body relies on a liver enzyme called CYP3A4 to break it down and clear it out. Some lab studies hint that fo-ti might slow that same enzyme down. If that happened, lonafarnib could build up more than expected, which may mean stronger side effects like nausea, vomiting, diarrhea, poor appetite, or feeling unusually tired.

I want to be honest about how thin this evidence is. It comes only from test-tube research, the animal data actually disagreed, and it has never been seen in real patients. So this is more of a theoretical caution than a proven problem. Still, lonafarnib is a serious medication, so please run any fo-ti use past your doctor or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  2. Zhang Y, Ding T, Diao T, Deng M, Chen S. Effects of Polygonum multiflorum on the activity of cytochrome P450 isoforms in rats. Pharmazie 2015;70(1):47-54. DOI
  3. Xing Y, Yu Q, Zhou L, et al. Cytochrome P450-mediated herb-drug interaction (HDI) of Polygonum multiflorum Thunb. based on pharmacokinetic studies and in vitro inhibition assays. Phytomedicine 2023;112:154710. PubMed

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

Fo-ti Also Interacts With Other Medications

Fo-ti has 1,256 moderate known drug interactions in our database — the Lonafarnib one above is among them. If you take anything else, check it against the full list below.

Moderate 1,256 No known interaction 1,574 (incl. Lonafarnib)
Taking anything else?

Check Another of Your Medications Against Fo-ti

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

Everything else you take

See Every Supplement That Interacts With Lonafarnib

This page covers Fo-ti only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Lonafarnib page lists 160 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 5 major · 115 moderate · 40 minor.

From our pharmacist’s overview on the Lonafarnib page

“If you or your child takes lonafarnib (Zokinvy) for progeria, treat supplements with real caution. Most of the 160 flagged ingredients cross paths with the CYP3A4 enzyme, the same one that handles lonafarnib, so the traffic runs both ways.”

Reviewed by 2 · Jul 18, 2026

Open the Lonafarnib interaction page

One more smart check

Taking Fo-ti as Part of a Dietary Supplement Product? Check It for Interactions

We hold 976 real supplement products containing Fo-ti, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Fo-ti. Your product may carry other ingredients that interact with Lonafarnib too, on top of Fo-ti — 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 Fo-ti and Lonafarnib 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 Fo-ti
Top 25%

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

29 days ago today
Medication Lonafarnib
Top half

#1,367 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 Fo-ti

What is Fo-ti?

  • Anti-aging and longevity
  • Hair graying and hair loss
  • General tonic for vitality
  • Constipation
  • High cholesterol

Fo-ti (He Shou Wu) is a root used in traditional Chinese medicine, often promoted for healthy aging and hair. High-quality human evidence for these benefits is limited, and processed Fo-ti has been linked to reports of liver injury, so caution and professional guidance are important.

Read the full Fo-ti monograph & all interactions
Medication

About Lonafarnib

What Is Lonafarnib Used For?

Brand name: Zokinvy

Zokinvy (lonafarnib) is approved for patients 12 months of age and older who have a body surface area of 0.39 m² or above. It is used to reduce the risk of mortality in Hutchinson-Gilford Progeria Syndrome (HGPS) — a rare, severe premature-aging disorder.

Zokinvy is also used to treat processing-deficient Progeroid Laminopathies — a related group of rare genetic conditions — specifically those caused by a heterozygous LMNA mutation with progerin-like protein buildup, or by homozygous or compound heterozygous ZMPSTE24 mutations. It is not indicated for other Progeroid Syndromes or processing-proficient Progeroid Laminopathies.

See full Lonafarnib drug information
Keep checking

Other Drugs & Fo-ti

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

0Major
1,256Moderate
0Minor
1,573No known interaction
1,256 Moderate 1,573 No interaction
Moderate

1,256 interactions

Showing 60 of 1,256 moderate interactions — see all 1,256 on the Fo-ti page.

No interaction 1,573 drugs checked — show the list

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

Showing the 60 most looked-up of 1,573 medications checked with no known interaction — see the full Fo-ti list.

See the full Fo-ti interactions page
See every supplement checked against Lonafarnib, 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
Fo-ti monograph › Uses, safety, and every drug interaction in one place Lonafarnib supplement interactions › Every supplement checked against Lonafarnib, ranked by severity Lonafarnib 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 Fo-ti and Lonafarnib Together: Common Questions

Can you take Fo-ti with Lonafarnib?
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 Fo-ti and Lonafarnib?
Lonafarnib belongs to more than one drug category, and Fo-ti 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 Fo-ti and Lonafarnib 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 Lonafarnib and Fo-ti?

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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.