Sex, it goes without saying, is complicated. For many people, it’s a source of worry as much as pleasure. Men in particular worry about penis size, getting hard, staying hard, lasting long enough to please their partner—and that’s just for starters.

For some men, the thorough enjoyment of sex also hinges on how much they ejaculate. Enter PEVR, or perceived ejaculate volume reduction.

PEVR, or the proof is in the pudding

The World Health Organization reports the average man’s ejaculate measures around 3.7 milliliters (ml), or about three-quarters of a teaspoonful. Any amount down to about 1.5 ml is considered normal.

Still, it’s important to remember that as men age, they often experience lower semen volume for several reasons: