In a recent interview with ESPN’s Gary Miller, Chicago Cubs outfielder Moises Alou revealed that during baseball season he urinates on his hands to toughen them up. Alou, one of the few major leaguers who doesn’t wear gloves while batting, is backed up by Yankees catcher Jorge Posada, who says, “You don’t want to shake my hand during spring training.” Even Cubs hurler Kerry Wood mentioned on a local radio show that he’s tried the technique to remedy blisters on his pitching hand (though he wryly added that there’s also a well-known clubhouse cure for headaches: “crapping in your hat”). Does urine really toughen the skin?

Quite the opposite. Proponents of urine therapy—and there are enough of these to have populated three World Conferences on the subject—believe consuming one’s own urine boosts the immune system, and they also recommend using it as a skin treatment. But most say urine softens the skin, rather than hardening it.

Plenty of traditional doctors and professional skeptics will tell you that urine therapy is a crock, but when it comes to skin care, urine-therapy devotees may be correct. Urea, a major component of urine, is a compound also used in many commercial moisturizing creams as a skin softener. It’s an active ingredient, for example, in Carmol 10 and 20 and in Dermal Therapy Lotion. (The makers of these lotions are not distilling urine, by the way; their urea is manufactured in a lab.)

But that doesn’t necessarily mean you can save money on moisturizer by drinking a ton of water. As a delivery device for urea, lotion is much more effective than pee; in order for the urea in urine to have an effect, you’d need to soak your hands long enough for the urea to be absorbed by your skin, at least five minutes. While there’s no hygiene-related reason not to do so—”Urine is sterile, if a bit gross,” writes Stanford dermatology professor Dr. Alexa Boer Kimball in an e-mail—those with eczema or dermatitis may see their conditions exacerbated by contact with urine.

So, why do baseball players do it? Athletes, especially baseball players, are superstitious creatures. If Moises Alou thinks peeing on his hands has helped him hit .301 in his 14-year major league career, who are we to tell him otherwise? Wood noted in his ESPN radio interview that he experimented with urine only when he had blisters that wouldn’t go away, and he was desperate enough to try anything. “Someone tells you something works,” Wood said, and you give it a try, because saving your career is worth any sacrifice—even peeing on your own hands.

Next question?

Explainer thanks Dr. Christopher Harmon, Dr. Alexa Boer Kimball, the American Sports Medicine Institute, and the American Academy of Dermatology.

Correction, May 18, 2004: The photo that originally accompanied this piece was of Chicago Cubs pitcher Carlos Zambrano, not outfielder Moises Alou. Slate regrets the error.