I am an older guy who now has what I judge to be moderate gyne whether from taking cimetidine (tagemet), age or other meds. I have accepted having larger breasts - must admit I sort enjoy having them but attitude would be considerably different if I was much younger. Majority of older men have mild to moderate gyne and most seem to accept it.
Cimetidine was the first H2 inhibitor developed - inhibit gastric acid secretion. It is available over the counter in the USA and is pretty cheap. I suffer from GERD and plan to continue taking cimetidine. I prefer not getting severe gyne where one has to wear a bra for support. But I guess I run the risk of preceding to that state. I wouldn't be a first though.
Cimetidine is apparently a weak anti-androgen and blocks one mechanism of the metabolism of estradiol which increases the estradiol level in the body. Both males and females produce this estrogen. It is the estradiol which stimulates breast tissue to grow.