Drug & supplement interaction

Trendione + Trastuzumab

Trastuzumab brand name: Herceptin.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Trendione and Trastuzumab in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

Know someone taking this? Share
Interaction report

Trendione and Trastuzumab

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Trastuzumab and Trendione in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Trendione at all — not against Trastuzumab, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Trendione safety at a glance

Trendione overall Avoid This is a synthetic anabolic steroid with serious safety concerns and no established safe use.
Pregnancy Possibly Unsafe When used orally. Prohormones can be converted to active hormones in the body and cause adverse effects such as menstrual irregularities, infertility, hair loss... Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used orally. Prohormones can be converted to active hormones in the body and cause adverse effects such as menstrual irregularities, infertility, hair loss... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Trastuzumab and Trendione? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Trastuzumab’s Own FDA Label Lists

This is not an interaction — none of it involves Trendione. These are the most notable effects listed in the ADVERSE REACTIONS section of Trastuzumab’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 10 of them are worth acting on rather than waiting out — marked below.

  • Trouble swallowing Worth acting on
  • Low potassium Worth acting on
  • Heart failure Worth acting on
  • An irregular heartbeat Worth acting on
  • Low mood Worth acting on
  • A low platelet count Worth acting on
  • Kidney problems Worth acting on
  • Anemia Worth acting on
  • Raised blood pressure Worth acting on
  • Shortness of breath Worth acting on

Showing the 10 most notable of 43 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Trastuzumab. Read the label on DailyMed › Where a percentage is shown, it is the share of 86,493 voluntary FDA FAERS reports for Trastuzumab that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Trendione’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Trendione side to compare — that is a limit of the record, not a statement that Trendione has no side effects.

Special populations

Trendione in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Unsafe

When used orally. Prohormones can be converted to active hormones in the body and cause adverse effects such as menstrual irregularities, infertility, hair loss, and acne. Prohormones have also been associated with hepatotoxicity and increased risk of cardiovascular disease. The U.S. Food and Drug Administration and other regulatory agencies warn that dietary supplements containing prohormones are dangerous. Avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

How much people look this up

Where Trendione and Trastuzumab 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 Trendione
Steady interest

#1,163 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Trastuzumab
Steady interest

#1,762 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Trendione reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Trendione and Trastuzumab records this page draws on were last updated June 22, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Trendione

What is Trendione?

  • Muscle building
  • Strength gains
  • Body recomposition
  • Athletic performance

Trendione (also marketed as estra-4,9,11-trien-3,17-dione) is a synthetic anabolic steroid sold as a so-called "prohormone" or "designer steroid," not a natural herb or vitamin. It is not a legitimate dietary supplement, has not been proven safe in humans, and is linked to potentially serious side effects, including liver harm. We strongly advise against using it and recommend talking with your doctor or pharmacist.

Not applicable; Trendione is a synthetic steroid compound, not a plant part · Capsules, tablets, oral powders (sold as a bodybuilding supplement)

An interaction check asks whether these two react with each other — it does not ask whether Trendione is a good idea for someone in your situation. Here is what our Trendione record says about it on its own.

Trendione: dosing

There is no established safe or effective dose for Trendione. Because it is a synthetic steroid rather than a studied medicine, no health authority has set a recommended amount.We do not provide dosing for this product because we do not recommend using it.

From our Trendione monograph — the full record covers uses, side effects and every documented interaction.

Read the full Trendione monograph & all interactions
Medication

About Trastuzumab Injection

What Is Trastuzumab Injection Used For?

Brand name: Herceptin

Trastuzumab injection is used in adults to treat certain cancers that overexpress the HER2 protein. For breast cancer, it is used as adjuvant (after-surgery) treatment for early-stage HER2-positive breast cancer, in combination with certain chemotherapy regimens, as well as for metastatic (spread) HER2-positive breast cancer — either with paclitaxel as a first-line treatment or as a single agent after prior chemotherapy.

Ontruzant is also indicated in adults for treatment of HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma (a type of stomach or esophageal junction cancer), in combination with cisplatin and capecitabine or 5-fluorouracil, for patients who have not received prior treatment for metastatic disease. Patients must be selected based on FDA-approved HER2 testing before starting therapy.

Most-Reported Side Effects for Trastuzumab

From FAERS, the FDA’s public side-effect reporting system (88,598 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 7,825 reports
Nausea 6,098 reports
Fatigue 5,551 reports
Alopecia 5,432 reports
Disease progression 4,960 reports
See full Trastuzumab Injection drug information
Keep checking

Other Drugs & Trendione

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

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

Trendione References

The 1 references that drive our Trendione monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Joseph JF, Parr MK. Synthetic androgens as designer supplements. Curr Neuropharmacol. 2015;13(1):89-100. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Trendione and Trastuzumab Together: Common Questions

Is it safe to take Trendione with Trastuzumab?
We do not list a known interaction between Trendione and Trastuzumab. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.

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

Still Have a Question About Trastuzumab and Trendione?

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.