Drug & supplement interaction

Fo-ti + Prasterone (prescription drug)

Prasterone (prescription drug) brand name: Intrarosa.

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

Fo-ti has a moderate interaction with Prasterone (prescription drug). Theoretically, taking large amounts of fo-ti might interfere with hormone replacement therapy through competition for estrogen receptors.

Read the full interaction report
SeverityModerate
LikelihoodProbable
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Fo-ti and Prasterone (prescription drug)

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ESTROGENS

Why this applies to Prasterone (prescription drug)

Prasterone (prescription drug) falls under ESTROGENS — the group Fo-ti interacts with.

Theoretically, taking large amounts of fo-ti might interfere with hormone replacement therapy through competition for estrogen receptors.
In vitro research suggests that fo-ti extract has estrogenic activity.
Severity Moderate Likelihood Probable Evidence D

Interaction 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..

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

Here's the short version on combining Fo-ti with Intrarosa (prasterone). Prasterone is a vaginal insert your body converts into estrogen and other hormones right where it's needed, easing painful intercourse after menopause. The concern on file is that Fo-ti has shown estrogen-like activity in lab dishes, which means it could in theory compete at estrogen receptors and slightly throw off how your hormone treatment works.

I want to be honest about the strength of this: it's theoretical, based only on test-tube and animal studies, and it would mainly apply to concentrated Fo-ti supplements, not tiny amounts. We don't have good human data here. Still, since this involves hormones, it's worth a quick chat with your pharmacist or doctor before pairing them, especially given Fo-ti's separate liver concerns.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Oerter Klein KO, Janfaza M, Wong JA, Chang RJ. Estrogen bioactivity in Fo-Ti and other herbs used for their estrogen-like effects as determined by a recombinant cell bioassay. J Clin Endocrinol Metab 2003;88:4077-9.. PubMed
  2. Zhang CZ, Wang SX, Zhang Y, et al. In vitro estrogenic activities of Chinese medicinal plants traditionally used for the management of menopausal symptoms. J Ethnopharmacol 2005;98:295-300. PubMed
  3. Kang, S. C., Lee, C. M., Choi, H., Lee, J. H., Oh, J. S., Kwak, J. H., and Zee, O. P. Evaluation of oriental medicinal herbs for estrogenic and antiproliferative activities. Phytother Res 2006;20(11):1017-1019. 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 1,258 moderate known drug interactions in our database — the Prasterone (prescription drug) one above is one of them. If you take anything else, check it against the full list below.

Moderate 1,258 No known interaction 1,572 (incl. Prasterone (prescription drug))
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 Prasterone (prescription drug)

This page covers Fo-ti only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Prasterone (prescription drug) page lists 63 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Grapefruit (major), Aletris (moderate), Alfalfa (moderate), Androstenediol (moderate) and Androstenedione (moderate).

By severity: 1 major · 56 moderate · 6 minor.

From our pharmacist’s overview on the Prasterone (prescription drug) page

“Grapefruit is the single major-rated interaction on prasterone's (Intrarosa) list, and it earns that spot. It blocks the enzyme that clears estrogens, so estrogen levels can climb, and side effects with them.”

Reviewed by 2 · Jul 18, 2026

Open the Prasterone (prescription drug) 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 Prasterone (prescription drug) 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 Prasterone (prescription drug) 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 Prasterone (prescription drug)
Top 5%

#134 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 Prasterone Vaginal

What Is Prasterone Vaginal Used For?

Brand name: Intrarosa

Intrarosa (prasterone) vaginal insert is used to treat moderate to severe dyspareunia — that is, pain during sex — which is a symptom of vulvar and vaginal atrophy (thinning and drying of vaginal tissues) caused by menopause.

See full Prasterone Vaginal 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
1,258Moderate
0Minor
1,571No known interaction
1,258 Moderate 1,571 No interaction
Moderate

1,258 interactions

Showing 60 of 1,258 moderate interactions — see all 1,258 on the Fo-ti page.

No interaction 1,571 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 1,571 medications checked with no known interaction — see the full Fo-ti list.

See the full Fo-ti interactions page
See every supplement checked against Prasterone (prescription drug), 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 Prasterone (prescription drug) supplement interactions › Every supplement checked against Prasterone (prescription drug), ranked by severity Prasterone Vaginal 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 Prasterone (prescription drug) Together: Common Questions

Can you take Fo-ti with Prasterone (prescription drug)?
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.
How serious is the Fo-ti and Prasterone (prescription drug) 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 Prasterone (prescription drug) and Fo-ti?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.