Drug & supplement interaction

Danshen + ADO-Trastuzumab Emtansine

ADO-Trastuzumab Emtansine brand name: Kadcyla.

Moderate Interaction
The bottom line Moderate

Danshen has a moderate interaction with ADO-Trastuzumab Emtansine. Danshen might alter the levels and clinical effects of drugs metabolized by CYP3A4.

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

Danshen and ADO-Trastuzumab Emtansine

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to ADO-Trastuzumab Emtansine

ADO-Trastuzumab Emtansine 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 thing about Kadcyla (ado-trastuzumab emtansine): it's an antibody that carries a powerful chemo payload called DM1 directly into cancer cells. Once that payload is released, your liver clears part of it using an enzyme called CYP3A4. Danshen can nudge that enzyme in either direction, so on paper it could change how much active chemo sticks around in your body.

If Danshen blocks the enzyme, levels could climb, raising the chance of side effects like low platelets, bleeding, liver irritation, or nerve tingling. If it speeds the enzyme up over a couple weeks, the drug may clear faster and work less well. On top of that, Danshen itself can thin the blood, which is a real worry since Kadcyla already lowers platelets. This is a serious cancer medicine, so please don't add Danshen without first checking with your oncology team.

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

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 ADO-Trastuzumab Emtansine one above is one of them. If you take anything else, check it against the full list below.

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 ADO-Trastuzumab Emtansine

This page covers Danshen only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the ADO-Trastuzumab Emtansine page lists 121 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 2 major · 87 moderate · 32 minor.

From our pharmacist’s overview on the ADO-Trastuzumab Emtansine page

“If you're taking ado-trastuzumab emtansine (Kadcyla) for HER2-positive breast cancer, treat this list as one to check carefully, not casually. Every one of the 121 flagged ingredients affects the same enzyme, CYP3A4, which your body uses to clear part of this medicine.”

Reviewed by 2 · Jul 18, 2026

Open the ADO-Trastuzumab Emtansine 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 ADO-Trastuzumab Emtansine 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 ADO-Trastuzumab Emtansine 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

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

29 days ago today
Medication ADO-Trastuzumab Emtansine
Top 10%

#273 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 Ado-trastuzumab Emtansine Injection

What Is Ado-trastuzumab Emtansine Injection Used For?

Brand name: Kadcyla

Kadcyla (ado-trastuzumab emtansine) is used on its own to treat HER2-positive metastatic breast cancer in adults who have already received trastuzumab and a taxane chemotherapy, either together or separately. It is used when cancer has come back or spread, or when the disease returned within six months of finishing earlier treatment.

Kadcyla is also used as adjuvant (after-surgery) treatment for HER2-positive early breast cancer in patients who still had remaining cancer after completing neoadjuvant (pre-surgery) treatment with a taxane and trastuzumab. Patients must be tested for HER2 overexpression or gene amplification using an FDA-authorized test before starting Kadcyla.

See full Ado-trastuzumab Emtansine Injection 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
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
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

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Pharmacist Counseling Corner

Taking Danshen and ADO-Trastuzumab Emtansine Together: Common Questions

Can you take Danshen with ADO-Trastuzumab Emtansine?
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 Danshen and ADO-Trastuzumab Emtansine 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 ADO-Trastuzumab Emtansine 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.