https://www.nature.com/articles/s41443-023-00780-8

"Purposefully reducing the frequency of ejaculation, coined “semen retention”, and the similar practice of “NoFap”, have been popularized on social media. They are frequently accompanied by unsubstantiated claims of health benefits."

"Despite no scientific evidence, these courses claim to improve various aspects of men’s health and can be potentially damaging financially, physically, and mentally to participants."

This looks interesting.