No. There is no evidence for it, and no plausible mechanism.
Transcript
Does masturbation cause hair loss? It's one of the most searched hair questions on earth, so let's answer it. No. The idea dates back to Victorian pamphlets about losing protein. Semen contains about five grams. Testosterone does rise briefly afterwards, then settles within the hour. It never comes close to changing what your follicles do. Whatever's happening on your head, that isn't it.
The idea dates back to Victorian pamphlets about losing protein — semen contains about five grams. Testosterone does rise briefly afterwards and then settles within the hour, nowhere near enough to change what a follicle does. Pattern hair loss is driven by inherited sensitivity to DHT, and it runs on a timescale of years.