Drug & supplement interaction

Danshen + Toremifene Citrate

Toremifene Citrate brand name: Fareston.

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

Toremifene Citrate falls into 2 drug categories that Danshen can interact with; the most serious is rated moderate. Danshen might alter the levels and clinical effects of drugs metabolized by CYP3A4.

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

Danshen and Toremifene Citrate

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

Why Are There 2 Interactions?

Danshen interacts with whole categories of medication. Toremifene Citrate falls into 2 of those categories, so it can interact with Danshen 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 3A4 (CYP3A4) SUBSTRATES

1 of 2

Why this applies to Toremifene Citrate

Toremifene Citrate falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Danshen interacts with.

Danshen might alter the levels and clinical effects of drugs metabolized by CYP3A4.
Preliminary clinical research in healthy males shows that the administration of danshen for 10-14 days induces intestinal CYP3A4 and increases the clearance of midazolam, a CYP3A4 substrate. The maximum concentration of midazolam was decreased by 31% to 67%, and drug levels were decreased by 27% to 80%. However, a single dose of danshen has the opposite effect, increasing maximum concentrations of midazolam by 87%.
Severity Moderate Likelihood Possible Evidence B

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: your toremifene (Fareston) is processed by a liver and gut enzyme called CYP3A4. Danshen can mess with that same enzyme, but in a tricky way. Taken steadily for a couple of weeks, danshen appears to speed up that enzyme, which could clear toremifene out of your body faster and leave less of it to do its job against the breast cancer. A single dose seems to do the opposite. Either way, the levels become unpredictable.

Because toremifene is an active drug (not a prodrug that needs switching on), the worry with regular danshen use is a weaker anti-estrogen effect. With a cancer treatment, I wouldn't gamble on that. Please check with your oncologist or pharmacist before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Qiu F, Wang G, Zhang R, Sun J, et al. Effect of danshen extract on the activity of CYP3A4 in healthy volunteers. Br J Clin Pharmacol 2010;69:656-62. PubMed
  2. Qiu F, Jiang J, Ma Y, Wang G, Gao C, Zhang X, Zhang L, Liu S, He M, Zhu L, Ye Y, Li Q, Miao P. Opposite Effects of Single-Dose and Multidose Administration of the Ethanol Extract of Danshen on CYP3A in Healthy Volunteers. Evid Based Complement Alternat Me PubMed
Moderate

GLUCURONIDATED DRUGS

2 of 2

Toremifene Citrate also falls under GLUCURONIDATED DRUGS.

Theoretically, danshen might affect the levels and clinical effects of drugs requiring glucuronidation.
In vitro research shows that danshen induces the expression of glucuronosyltransferases. However, it also inhibits the activity of glucuronosyltransferases, including various members of the 1A and 2B families. The extent of inhibition of a specific glucuronosyltransferase seems to be dependent on whether or not the danshen is processed via 'sweating'. This type of processing may affect the levels of constituents in danshen that alter glucuronosyltransferase activity. So far, 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 situation with Danshen and your toremifene (Fareston). Part of how your body clears toremifene relies on a process called glucuronidation, where the liver tags the drug so it can be removed. Lab studies suggest Danshen can pull this process in both directions: it may speed it up in some cases and slow it down in others, depending on how the Danshen was prepared. Toremifene is an active drug (not a prodrug), so if Danshen slows that clearance, levels could rise and you might see more side effects like hot flashes, nausea, or dizziness. If it speeds clearance, the drug could work less well.

I want to be honest with you though: this is purely theoretical, based on test-tube research, and has not been reported in people. Still, since this is cancer treatment, please run it by your oncologist or pharmacist before combining the two.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Liu J, Shi Y, Wu C, et al. Comparison of sweated and non-sweated ethanol extracts of Salvia miltiorrhiza Bge. (Danshen) effects on human and rat hepatic UDP-glucuronosyltransferase and preclinic herb-drug interaction potential evaluation. Curr Drug Metab

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

Danshen Also Interacts With Other Medications

Danshen has 123 major, 935 moderate known drug interactions in our database — the Toremifene Citrate one above is among them. If you take anything else, check it against the full list below.

Major 123 Moderate 935 No known interaction 1,772 (incl. Toremifene Citrate)
Taking anything else?

Check Another of Your Medications Against Danshen

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

Everything else you take

See Every Supplement That Interacts With Toremifene Citrate

This page covers Danshen only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Toremifene Citrate page lists 143 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 101 moderate · 39 minor.

From our pharmacist’s overview on the Toremifene Citrate page

“Toremifene (Fareston) treats hormone receptor positive breast cancer, and I'd want you to be genuinely careful with supplements while you're on it. Of the 143 flagged ingredients, 121 can change how your liver clears toremifene through an enzyme called CYP3A4, so your blood level of the drug can drift up or down.”

Reviewed by 2 · Jul 18, 2026

Open the Toremifene Citrate interaction page

One more smart check

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

We hold 18 real supplement products containing Danshen, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Danshen. Your product may carry other ingredients that interact with Toremifene Citrate too, on top of Danshen — 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 Danshen and Toremifene Citrate 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 Danshen
Top half

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

29 days ago today
Medication Toremifene Citrate
Steady interest

#2,633 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 Danshen

What is Danshen?

Danshen
  • Heart and circulation support
  • Angina (chest pain)
  • High blood pressure
  • Anxiety and stress
  • Liver health

Danshen is a root used in traditional Chinese medicine, mainly for heart and circulation problems. Some early research is promising, but the evidence is not strong enough to confirm it works for any condition, and it may affect blood clotting. Talk to a pharmacist or doctor before using it, especially if you take other medicines or have a health condition.

Read the full Danshen monograph & all interactions
Medication

About Toremifene

What Is Toremifene Used For?

Brand name: Fareston

Toremifene citrate tablets — sold as Fareston and under the generic name toremifene citrate — are used to treat metastatic breast cancer (breast cancer that has spread to other parts of the body) in postmenopausal women. It is specifically approved for tumors that test positive for estrogen receptors, or for tumors where the receptor status is not known.

See full Toremifene drug information
Keep checking

Other Drugs & Danshen

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

123Major
935Moderate
0Minor
1,771No known interaction
123 Major 935 Moderate 1,771 No interaction
Major

123 interactions

Showing 60 of 123 major interactions — see all 123 on the Danshen page.

Moderate

935 interactions

Showing 60 of 935 moderate interactions — see all 935 on the Danshen page.

No interaction 1,771 drugs checked — show the list

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

Showing the 60 most looked-up of 1,771 medications checked with no known interaction — see the full Danshen list.

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

Can you take Danshen with Toremifene Citrate?
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 Danshen and Toremifene Citrate?
Toremifene Citrate belongs to more than one drug category, and Danshen 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 Danshen and Toremifene Citrate 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 Toremifene Citrate and Danshen?

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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.