At what age do men stop being sexually active got no real answers. Still, reports tell by 40 the libido in a man decreases by 1% each year. Men don't stop being sexually active at a specific age; many remain so into their 70s, 80s, and beyond, though activity often declines gradually due to factors like lower testosterone, chronic conditions (diabetes, heart disease), medications, stress, and partner availability, but issues like erectile dysfunction (ED) are treatable, and a healthy lifestyle (diet, exercise, no smoking) supports continued intimacy.