Credit: Illustration by Slug Signorino

What’s the story on the effectiveness of the various baldness treatments on the market today? The many products advertised on TV make some pretty amazing claims. Is there any independent research available to compare the differenttreatments? —T.H., via e-mail

When minoxidil hit the market 20 years ago, I thought: At least that’ll be the end of the damn baldness questions. No such luck. Although modern baldness treatments work better than, say, penis-enlargement devices, don’t expect to come away with hair that’ll get you the Democratic presidential nomination. A rundown on what works and what doesn’t:

1. Castration. Don’t be a wuss. A real man does what it takes to get results. Male pattern baldness is thought to arise from a particular version of an androgen receptor gene. If you’ve got the wrong one, a testosterone breakdown product, dihydrotestosterone (DHT), gradually reduces hair growth by shrinking the size of the hair follicle, meaning thinner and eventually no hair. No testosterone, no baldness. Whatever other beefs they may have, eunuchs have been famed since the days of Hippocrates for killer hair. Caution: Castration is best thought of as a preventive measure. If DHT has already wasted your follicles, shutting off the tap now won’t necessarily bring them back.

2. Minoxidil. Originally a high blood pressure remedy with unexpected side effects, minoxidil was the first FDA-approved treatment for male pattern baldness. Why it works is still a mystery—the best guess is that it shortens hair’s resting phase and increases the growth phase.

Hair regrown by minoxidil tends to be fine, like baby hair. Minoxidil has been proven effective for treating hair loss only on the crown of the head, although some studies show improved frontal hair growth. Don’t expect miracles. I knew a balding guy in his early 20s who got loads of free minoxidil samples from his father-in-law, who was in the drug industry. Thinking more chest hair might impress the wife, he slathered the stuff on his pecs every morning. Result: a rash requiring outpatient treatment, and let’s just say he didn’t rise in the estimation of the wife.

3. Finasteride. Like minoxidil, finasteride was first used to treat another medical condition—in this case, enlarged prostate. Unlike minoxidil, finasteride attacks the source of the problem by blocking an enzyme that converts testosterone into the troublesome DHT. The net result is about the same: The hair growth period is extended and the resting period reduced, resulting in more and denser hair growth; studies are mixed on whether it increases hair thickness. Although you can’t put much stock in anecdotal evidence, a friend who tried finasteride experienced total regrowth on the crown plus three-quarters of an inch in hairline resurgence. After a year on the stuff he started seeing other effects, including unusually thick hairs plus twinned and occasionally triplet hairs. Being an anal-retentive scientist type, my friend had collected loose hairs for nearly a year before starting on finasteride. Comparing before and after, he found an increase in hair thickness of roughly 30 percent.

4. Hair transplants, etc.Both minoxidil and finasteride have side effects and need to be used daily lest hair growth stop or reverse. Hair transplants, or plugs, may be a more permanent solution—DHT-resistant hair from the back of your head is shifted to wherever it’s needed more. The process is extraordinarily involved, requiring as many as 5,000 tiny skin grafts containing one to four hairs each in a marathon surgical session lasting 12 hours or more. An even more drastic remedy is scalp reduction. Here part of your bald spot is surgically removed and the surrounding, presumably hairier skin is stretched to cover the gap and sutured into place. The procedure is suitable for improving hair coverage only in the back and on top of your head, can lead to permanent scarring at the incision line, and may require implants to hide the scars and beef up coverage on the stretched-out skin.

Whatever drawbacks methods 2 through 4 may have, they’re an improvement over the situation 50 years ago, when your choice was method 1 or wear a hat. Nonetheless, the search for better techniques continues. Saw palmetto extract has been shown to suppress DHT production, but research on it to date is scant and unconvincing. Cell multiplication may hold more promise. Recently a company in the U.K. successfully demonstrated a method of harvesting dermal papilla cells, the ones at the base of a hair follicle, and growing them in the lab into clumps of 10,000 or more, which can then be injected into the skin. At each successful injection point, a new hair grows, making surgical hair treatment cheaper and less painful. Should you be a balding woman, T., you can try variants on all the above unless you’re of childbearing age, in which case nix the finasteride due to risk of birth defects. Oh, and you can skip the castration, too.—Cecil Adams

Is there something you need to get straight? Take it up with Cecil on the Straight Dope message board,, or write him at the Washington City Paper, 2390 Champlain St. NW, Washington, DC 20009. Cecil’s most recent compendium of knowledge, Triumph of the Straight Dope, is available at bookstores everywhere.