No human study has ever tested reishi, cordyceps, lion's mane, chaga or Amanita alongside hormonal contraception. So anyone who tells you a mushroom definitely does or doesn't affect the pill is guessing. What we do know is how supplements can undermine contraception in general, and one of those routes is far more ordinary than liver enzymes: being sick. If you vomit within 3 hours of a combined pill, the NHS says to treat it as a missed dose. Amanita mushrooms cause vomiting often.
There's no human evidence on medicinal mushrooms and hormonal contraception, in either direction. The established risks come from elsewhere. St John's wort, a strong CYP3A4 enzyme inducer, increased breakthrough bleeding in three of four studies in a 2016 systematic review, and one study found probable ovulation. And vomiting stops a pill being absorbed: the NHS advises taking another combined pill if you're sick within 3 hours (4 hours for Qlaira or Zoely). Amanita causes GI symptoms often; in Moss and Hendrickson's poison-centre series, 35% of Amanita muscaria and 80% of Amanita pantherina cases had them.
This is a safety guide, so there's nothing to buy here. Your contraceptive's patient leaflet and your pharmacist are the authority on your specific method; what follows explains the reasoning so you know what to ask.
Has Anyone Studied Mushroom Supplements With the Pill?
No. In PubMed searches for this article, we found no clinical or pharmacokinetic study of any medicinal mushroom taken with a combined pill, progestogen-only pill, implant, injection or hormonal coil. That includes the mushrooms most often taken daily: reishi, cordyceps, lion's mane, chaga and turkey tail.
That's worth sitting with for a moment, because it means both common claims are unsupported. "Mushrooms are natural, so they won't interfere" isn't evidence. Neither is a warning list that flags every supplement as a contraceptive risk. Our medication interactions guide makes the same point about the whole category: very few mushroom–drug interactions have a documented human case behind them, and most warnings are reasoning from mechanism.
So the useful question isn't "is this mushroom safe with my pill?" It's "which mechanisms could matter, and does this product give any of them a foothold?"
How Could a Supplement Make Contraception Less Reliable?
There are three plausible routes, and they're not equally likely.
- Enzyme induction. Both the oestrogen (ethinylestradiol) and the progestogen in hormonal contraceptives are broken down by the liver enzyme CYP3A4. A substance that ramps up that enzyme can clear the hormones faster and lower their levels. This is well established for certain drugs and for St John's wort.
- Absorption loss. A pill only works if it stays in your gut long enough to be absorbed. Vomiting soon after taking it, or severe diarrhoea, can mean the hormones never reach your bloodstream.
- Hormone-active compounds. Some supplements contain compounds that interact with hormone pathways. In theory these could add to or muddy a contraceptive's effect, though there's no evidence of this happening with any mushroom.
Only the second route has an obvious, concrete link to a specific mushroom group. The first has a famous herbal precedent but no mushroom data. The third is lab-bench territory.
What Does the St John's Wort Story Teach Us?
It shows what a real supplement–contraceptive interaction looks like, and how much evidence it took to establish. Berry-Bibee and colleagues' 2016 systematic review screened 48 articles and found four studies comparing combined pills alone with combined pills plus St John's wort.
Three of the four showed more breakthrough bleeding when St John's wort was added. One found increased follicular growth and probable ovulation, the event contraception is meant to stop. Three showed changes in hormone pharmacokinetics suggesting lower exposure, and the only study without significant changes used a product low in hypericin. The authors concluded that the evidence was limited but raised concern for reduced efficacy, with weak-to-moderate induction of hormone metabolism.
Two lessons follow. First, even a strong, well-known enzyme inducer produced a mixed, modest-looking signal, which tells you how hard these interactions are to detect. Second, the problem isn't confined to pills. The NHS lists St John's wort among the remedies that can stop the contraceptive implant and the contraceptive injection working properly. Enzyme induction acts on the hormone after it's in your blood, whatever route it took to get there.
Why Is Amanita the Most Concrete Concern?
Because the problem is vomiting, and Amanita mushrooms cause it often. Moss and Hendrickson reviewed 34 ingestions of muscimol- and ibotenic-acid-containing mushrooms reported to a US regional poison centre. Any gastrointestinal symptoms were recorded in 35% of Amanita muscaria cases and 80% of Amanita pantherina cases, and all but one symptomatic patient developed symptoms within 6 hours.
Those were poisonings, mostly from foraging or accidental ingestion, not measured use of a dried product. Still, nausea and vomiting are among the recognised effects of these species, as our Amanita muscaria side effects guide and who should avoid Amanita pantherina both describe. If that vomiting lands within a few hours of a pill, the pill may not have been absorbed.
The NHS gives exact windows, and they differ by pill type:
| Pill type | Vomiting window per NHS guidance | What the NHS says to do |
|---|---|---|
| Combined pill (most brands) | Less than 3 hours after taking it | Take another pill straight away, then the next at the usual time |
| Combined pill (Qlaira or Zoely) | Up to 4 hours after taking it | Take another pill straight away, then the next at the usual time |
| Traditional progestogen-only pill | Within 2 hours | The pill may not work; check the leaflet or ask a pharmacist |
| Desogestrel or drospirenone progestogen-only pill | Within 3 to 4 hours | The pill may not work; check the leaflet or ask a pharmacist |
For the combined pill, the NHS adds that if you're still being sick, you should use another method such as condoms until you've taken the pill for 7 days without being sick. Diarrhoea lasting more than 24 hours also calls for backup until 7 days after it stops. For progestogen-only pills, severe watery diarrhoea can stop the pill working, and you may need emergency contraception.
Which methods does vomiting not affect?
Anything that doesn't depend on swallowing a tablet: the implant, the injection, the hormonal and copper coils, and the patch and vaginal ring, which deliver hormones without passing through the gut. So the vomiting risk is a pill problem. The enzyme-induction risk, as the St John's wort guidance shows, isn't.
How Do Common Mushrooms Rate?
Mostly as "no data", which is an honest answer rather than a reassuring one. Here's what's known for each.
| Mushroom or product | Contraceptive interaction data | What is known | Practical note |
|---|---|---|---|
| Reishi | None | Anti-androgenic activity in lab and rat studies (5α-reductase inhibition) | Hormone-adjacent, but no evidence it affects contraception |
| Cordyceps | None | Some research touches on hormone signalling | Mention it to your pharmacist |
| Lion's mane | None | No contraceptive-relevant data | No specific action beyond the usual |
| Chaga, turkey tail | None | No contraceptive-relevant data | No specific action beyond the usual |
| Amanita muscaria | None | GI symptoms in 35% of poison-centre cases | Keep away from pill timing; follow the vomiting rules |
| Amanita pantherina | None | GI symptoms in 80% of poison-centre cases | Higher vomiting risk; same rules, more caution |
| "Mood" or "stress" blends | Depends on ingredients | May contain St John's wort | Read the full ingredients list |
A word on reishi, since it's the one with hormone-related lab data. Fujita and colleagues found reishi extract had the strongest 5α-reductase inhibition of 19 mushrooms tested, and it reduced testosterone-driven prostate growth in castrated rats. That's anti-androgenic activity in a lab and an animal model. It says nothing about oestrogen or progestogen levels in a woman taking the pill, and nobody has measured that. Our reishi side effects and reishi and hormones articles cover the wider picture, and Cordyceps side effects covers its hormone-sensitive cautions.
Why Should You Check "Mood" and "Stress" Blends?
Because St John's wort is a mood herb, and blends sold for mood, stress or low winter energy sometimes include it alongside mushrooms. It may appear as St John's wort or by its botanical name, Hypericum perforatum. If you use hormonal contraception, that single ingredient matters more than any mushroom in the jar.
The same goes for any blend with a long ingredient list. Mushroom products increasingly add herbs, and some of those herbs have better-documented interaction profiles than the mushrooms do. Our guide to reading a mushroom supplement label shows how to find every ingredient, not just the headline one. Single-ingredient products make this far simpler.
What Should You Actually Do?
- Tell your pharmacist what you take. Name each product and its full ingredient list, not just "a mushroom supplement".
- Read your contraceptive's leaflet. It lists the medicines and herbal remedies known to affect your specific method.
- Avoid St John's wort in any form while relying on hormonal contraception, unless your prescriber has approved it.
- Keep Amanita away from pill time. If you vomit after taking a pill, follow the window for your pill type.
- Use backup contraception if you're unsure. Condoms cost little compared with the alternative.
- Think ahead if you're planning a pregnancy. Our guide to mushroom supplements during pregnancy explains why the evidence there is thin, too.
Most people who take a daily reishi or lion's mane capsule alongside the pill have no known reason to worry. The point is to know which situations do deserve attention: an enzyme-inducing herb hidden in a blend, or a bout of vomiting at the wrong time.
Frequently Asked Questions
Do mushroom supplements interact with birth control?
Nobody knows, because no human study has tested any medicinal mushroom with hormonal contraception. There's no evidence of an interaction, but also no evidence ruling one out. The established risks are enzyme-inducing herbs such as St John's wort, and vomiting or severe diarrhoea soon after taking a pill.
Can reishi make the pill less effective?
There's no evidence that it does. Reishi showed anti-androgenic activity in lab and rat studies, inhibiting the enzyme 5α-reductase, but nobody has measured its effect on contraceptive hormone levels. If you're concerned, tell your pharmacist, and use backup contraception until you've had advice.
What happens if I vomit after taking Amanita and the pill?
The pill may not have been absorbed. For most combined pills, the NHS advises taking another pill straight away if you vomit less than 3 hours after taking it (up to 4 hours for Qlaira or Zoely). Progestogen-only pill windows are 2 hours for traditional pills and 3 to 4 hours for desogestrel or drospirenone pills.
Does Amanita affect the implant or coil?
Vomiting doesn't affect the implant, injection, coils, patch or ring, because they don't rely on absorbing a tablet. No study has tested Amanita with any of them. Separately, the NHS notes that St John's wort can affect the implant and the injection, so check any herbal blend's ingredients.
Is St John's wort ever in mushroom blends?
It can be, particularly in blends sold for mood or stress. A 2016 systematic review found that St John's wort increased breakthrough bleeding in three of four studies with combined pills, and one study found probable ovulation. Check labels for "St John's wort" or "Hypericum perforatum".
Related Articles
- Mushroom Supplements and Medication Interactions
- Mushroom Supplements During Pregnancy
- Amanita Muscaria Side Effects and Interactions
- Who Should Avoid Amanita Pantherina?
- Reishi Side Effects and Drug Interactions
- Cordyceps Side Effects and Interactions
- Reishi for Menopause and Hormones
- How to Read a Mushroom Supplement Label
Sources
- Berry-Bibee EN, Kim MJ, Tepper NK, Riley HE, Curtis KM. Co-administration of St. John's wort and hormonal contraceptives: a systematic review. Contraception. 2016;94(6):668-677. PubMed 27444983
- Moss MJ, Hendrickson RG. Toxicity of muscimol and ibotenic acid containing mushrooms reported to a regional poison control center from 2002-2016. Clin Toxicol (Phila). 2019;57(2):99-103. PubMed 30073844
- Fujita R, Liu J, Shimizu K, Konishi F, Noda K, Kumamoto S, et al. Anti-androgenic activities of Ganoderma lucidum. J Ethnopharmacol. 2005;102(1):107-112. PubMed 16029938
- NHS. What to do if you're sick or have diarrhoea when taking the combined pill. nhs.uk
- NHS. What to do if you're sick or have diarrhoea when taking the progestogen-only pill. nhs.uk
- NHS. Who can use the contraceptive implant. nhs.uk
- NHS. Who can get the contraceptive injection. nhs.uk