Biohacking mogul Bryan Johnson has revealed his "first in-human observation" on the negative effects of magic mushrooms on sperm count. The compound, psilocybin, is often hailed as a wonder drug that could extend lifespan and improve Parkinson's symptoms. Johnson, who tested whether magic mushrooms are a longevity therapy, found that his sperm count decreased by 51% three days after the second dose and his total serum testosterone increased by 30%. However, his sex hormone-binding globulin (SHBG) levels increased by 37%. He believes these effects are negligible due to the systemic metabolic and anti-inflammatory benefits outweighing potential sperm count reductions.