If you were to make a list of "male worries," baldness would come in at a solid number two -- right after sex problems.

But if you go to a mainstream doctor for one, there's a good chance you'll end up battling the other. The FDA is warning that the hair growth drug Propecia (finasteride) can cause erectile dysfunction and problems with ejaculation and orgasm, including poor semen quality and infertility.

The drug can also cause your libido to come crashing to a halt, which might actually be a blessing if you can't achieve orgasm or even an erection.

What good's the desire if you lack the ability?

But the real outrage here isn't the side effects, which can last for months after you stop taking the drug.

It's the FDA's foot-dragging that led to this too-little, too-late warning, since these problems have been reported for years -- problems that should have been obvious from day one, since the drug "works" by blocking the very nature of manly function.

Thinning hair is actually a sign that the male body is working right -- evidence that it's successfully converting manly testosterone into the even more manly hormone dihydrotestosterone, which is about 10 times as powerful.

Maybe that's why women have always swooned over bald men like Yul Brenner and Telly Savalas -- or, for my younger readers, The Rock and Vin Diesel -- because bald men are practically oozing dihydrotestosterone.

Too much dihydrotestosterone, however, can cause hair to stop growing. Since finasteride blocks the conversion of testosterone into dihydrotestosterone, it can help restore hair... but at a huge cost.

So it's not at all surprising that men who take the med can end up battling severe and lasting sexual dysfunction. The only surprise here is that these side effects aren't even more common than what's been reported so far (and remember, no man likes to admit to sex problems -- so the reported numbers could very well be just the tip of the iceberg).

By the way, excess dihydrotestosterone can also lead to prostate growth, which is why the same drug is sold for enlarged prostates under the name of Proscar.

In fact, that was the drug's original purpose -- but when its makers noticed that men who took it got hairier, the side effect quickly became a marketing bonanza.

Don't bother.

Saw palmetto is far safer, taken both internally and used topically on the scalp. One recent study found that 60 percent of men with mild to moderate hair loss improved after taking a combination of saw palmetto and the plant sterol beta sitosterol for five months, compared to 11 percent of those on a placebo.