A Drug Commonly Used to Treat Erectile Dysfunction, May Also Help Regenerate Damaged Muscle. Research Suggests the Medication, Tadalafil Could Support Muscle Repair and Recovery by Influencing Biological Processes Involved in Muscle Regeneration in Mouse Models.

A highly upvoted r/science post reported on a study suggesting that "tadalafil, used to treat ED, may aid muscle regeneration," triggering a wave of jokes: u/backpackwayne quipped that the side effect is "erections lasting over four hours," while u/GeneralKosmosa and u/christopher_mtrl claimed the drug is also linked to reduced risks of dementia, stroke, and heart attack. On the factual level: the study is real, published by a team from the University of Foro Italico in Rome in Molecular Biology Reports. In in vitro experiments on mouse muscle precursor cells, tadalafil (a PDE5 inhibitor) promoted cell proliferation and survival, reduced cell death, and accelerated scratch-wound healing, but also delayed cell maturation into muscle fibers; the researchers explicitly emphasized this is an "encouraging early signal" and far from proving muscle growth or improved recovery in humans, and there is a risk of dangerous hypotension when combined with nitrates. The post's "regenerates muscle" headline is a moderate extrapolation from an in vitro cell study; human evidence is lacking.

Checked ✔ (Molecular Biology Reports, University of Foro Italico, Rome; in vitro experiment on mouse muscle precursor cells, PDE5 inhibition promoted proliferation/survival and delayed maturation; researchers state this is far from proving muscle growth in humans, and there is a hypotension risk).