Drug & supplement interaction

Croton Seeds + Sirolimus

Sirolimus brand name: Rapamune.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Croton Seeds and Sirolimus 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

Know someone taking this? Share
Interaction report

Croton Seeds and Sirolimus

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 Sirolimus and Croton Seeds 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 Croton Seeds at all — not against Sirolimus, 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.

Croton Seeds safety at a glance

Croton Seeds overall Avoid Croton seeds and croton oil are toxic and can cause severe, sometimes fatal poisoning.
Pregnancy Avoid Avoid completely; croton is a strong purgative and irritant that may harm pregnancy.
Breastfeeding Unsafe When used orally. Croton seed oil has abortifacient properties; avoid using. 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 Sirolimus and Croton Seeds? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Croton Seeds and Sirolimus May Share a Side Effect

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Dizziness Additional detail

    Croton Seeds

    “Orally, croton seeds can cause burning of the mouth, vomiting, dizziness, stupor, painful bowel movements, and collapse (18). Topically, croton seed oil can cause itching, burning and blistering of the skin (18).”

    Croton Seeds · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    1 source cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

    “Orally, croton seed oil can cause dizziness, stupor, and collapse (18).”

    Croton Seeds · Natural Medicines adverse-effect record, reported in vertigo.

    1 source cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

    Sirolimus

    Listed in the ADVERSE REACTIONS section of the FDA label for Sirolimus. Read the label on DailyMed ›

Reported for Croton Seeds but not commonly for Sirolimus: vomiting and itching.

Effects for Sirolimus come from the ADVERSE REACTIONS section of its FDA label; effects for Croton Seeds come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Croton Seeds in Pregnancy & Breastfeeding

Lactation Unsafe

When used orally. Croton seed oil has abortifacient properties; 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

From our Q&A

Questions About Croton Seeds or Sirolimus

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Croton Seeds or Sirolimus, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Sirolimus

This page covers Croton Seeds only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Sirolimus page lists 188 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 Active Hexose Correlated Compound (ahcc) (moderate).

By severity: 3 major · 149 moderate · 36 minor.

From our pharmacist’s overview on the Sirolimus page

“Sirolimus (Rapamune) is the anti-rejection medicine transplant patients depend on, and it is a narrow-therapeutic-index drug, meaning small shifts in its blood level can invite rejection on one side or toxicity on the other. That is why the 188 supplements on this page deserve genuine wariness, starting with the three rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Sirolimus interaction page

One more smart check

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

We hold 6 real supplement products containing Croton Seeds, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Croton Seeds. Even though Croton Seeds itself has no known interaction with Sirolimus, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Croton Seeds and Sirolimus 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 Croton Seeds
Steady interest

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

29 days ago today
Medication Sirolimus
Top half

#1,219 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 Croton Seeds reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Croton Seeds and Sirolimus records this page draws on were last updated July 11, 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 Croton Seeds

What is Croton Seeds?

  • Severe constipation (traditional purgative)
  • Digestive complaints
  • Skin conditions (topical, traditional)
  • Traditional Chinese and folk medicine remedies

Croton seeds and croton oil come from Croton tiglium, a plant historically used as a powerful purgative, but they are highly toxic and can be dangerous or even deadly. Because of the serious risk of poisoning, severe irritation, and burns, croton seeds are not recommended for self-use. If you are considering any product containing croton, talk to a doctor or pharmacist first.

Croton tiglium · Euphorbiaceae · Seeds and the oil pressed from the seeds (croton oil) · Croton oil, processed seeds, and traditional herbal preparations (rarely available as a standard supplement)

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

Croton Seeds: dosing

There is no safe, standardized dose of croton seeds or croton oil for self-care, and we will not suggest an amount. The difference between a traditional 'dose' and a poisonous amount is very small, which is part of why croton is considered so dangerous.We do not recommend taking croton seeds.

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

Read the full Croton Seeds monograph & all interactions
Medication

About Sirolimus

What Is Sirolimus Used For?

Brand name: Rapamune

Sirolimus oral solution and tablets are used to help prevent organ rejection in kidney (renal) transplant patients aged 13 and older. They are also used to treat lymphangioleiomyomatosis (LAM) — a rare lung disease in which abnormal muscle-like cells invade lung tissue.

Fyarro (sirolimus, intravenous injection) is used to treat adults with locally advanced, unresectable, or metastatic malignant PEComa — a rare tumor that grows in soft tissue or organs. Hyftor (sirolimus topical gel) is used to treat facial angiofibroma (small benign skin growths on the face) associated with tuberous sclerosis in adults and children aged 6 and older.

Most-Reported Side Effects for Sirolimus

From FAERS, the FDA’s public side-effect reporting system (13,394 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fever 525 reports
Diarrhea 515 reports
Pneumonia 487 reports
Acute kidney injury 435 reports
Thrombotic microangiopathy 376 reports
See full Sirolimus drug information
Keep checking

Other Drugs & Croton Seeds

Browse every other medication we’ve checked against Croton Seeds — 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

Croton Seeds References

The 2 references that drive our Croton Seeds 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. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  2. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

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 Croton Seeds and Sirolimus Together: Common Questions

Is it safe to take Croton Seeds with Sirolimus?
We do not list a known interaction between Croton Seeds and Sirolimus. 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.
Do Croton Seeds and Sirolimus have any of the same side effects?
Yes — our sources link each of them separately to one of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Does Sirolimus interact with any supplements?
Yes. Sirolimus has documented interactions with 188 supplements in our database — Croton Seeds is not one of them. The Sirolimus interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Sirolimus and Croton Seeds?

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.