Is lion's mane mushroom safe during pregnancy?

What does the evidence say about lion's mane mushroom during pregnancy?

1. Many dietary supplements have not been tested in pregnant women, and outside a few specific categories, the FDA is not authorized to review a supplement for safety before it is marketed. 1
2. Lion's mane is generally recognized as safe when consumed as a food, and it is marketed for cognitive function and gastrointestinal health support, but people with a known mushroom allergy should avoid it to reduce the chance of an allergic reaction. 2
3. A toxicological assessment of lion's mane mushroom powder found no adverse effects linked to the mushroom powder across acute and 90-day subchronic testing in adult rats, but the study evaluated non-pregnant animals and did not include reproductive or developmental toxicity testing. 3
4. A human pilot study gave healthy adults 1.8 grams of lion's mane a day for 28 days to look at cognitive and mood effects; the trial was not designed around pregnancy and does not establish a pregnancy-appropriate dose. 4
5. Reviewers of the existing lion's mane research describe clinical validation as still limited and say long-term human studies are needed to confirm early findings and establish safe dosage guidelines. 2

Is lion's mane mushroom safe in each trimester?

• First trimester. The first trimester is when major organs are forming, which is exactly when starting an unstudied concentrated supplement carries the most theoretical uncertainty. Lion's mane used as a culinary mushroom in a stir-fry is a different question than a standardized extract capsule.
• Second trimester. No pregnancy-specific research on lion's mane has emerged by the second trimester either. If cognitive fog or fatigue is the reason you are considering it, there is not yet human data showing it helps with pregnancy-related symptoms specifically.
• Third trimester. Third-trimester decisions about any new supplement are worth running by your delivery team, since some herbal products get flagged around procedures or delivery. There is no lion's mane-specific delivery guidance published, which itself reflects how little pregnancy research exists.