Conventional practitioners insist that the vast majority of advertised products that claim to fight male-pattern baldness -- from vitamin formulas to saw palmetto to massage oils -- haven't been shown to work. Some dermatologists recommend a combination of the anti-wrinkle drug Tretinoin (sold under such brand names as Retin-A) and minoxidil, one of two drugs approved for baldness, but there is no clear evidence that this mixture is any more effective than minoxidil alone. Likewise, zinc has been tried for many kinds of hair problems but has never been proven useful. Mainstream doctors dismiss techniques such as acupuncture for the same reason, and even acupuncturists differ among themselves about whether the ancient Chinese art can benefit a balding head.

Mainstream and nontraditional clinicians agree that it's easier to address any type of hair loss early and that therapy works best if a person sticks with it for at least several months. They also note that hair loss, or alopecia, can sometimes be avoided by changing grooming practices. Excessive pulling from tight rollers, pigtails or cornrows, for example, can cause scarring on the scalp; hot oil hair treatments and chemicals used in permanent waves can also cause baldness.

Hit or Miss Drugs

Male-pattern baldness, which is typically seen as a receding hairline and/or balding at the crown, is by far the most common form of hair loss, affecting about half of men by age 50. Contrary to popular belief that baldness passes from mother to son, it's likely that multiple genes from both the mother and the father are responsible.

In men with this trait, heightened sensitivity to the male hormone DHT is believed to shorten the time it takes for hair to fall out. This sensitivity also reduces the size of the follicles from which each hair sprouts. When this occurs, the follicles produce a different sort of hair: Instead of being able to grow long and thick, strands are short and fine, similar to those on the arms and legs.

Hereditary baldness usually develops over many years. If shedding or thinning begins suddenly and progresses quickly, people should seek medical advice because this could be the sign of such conditions as thyroid disease, lupus, diabetes, a scalp fungus or an iron or zinc deficiency.

The Food and Drug Administration (FDA) approved over-the-counter minoxidil in 1996 to fight hereditary balding. Sold as Rogaine and its generic equals, this topical product is thought to enlarge the follicles. The prescription drug finasteride (Propecia), approved for baldness by the FDA in 1997, is thought to work by blocking the formation of DHT.

The two drugs are more effective in the earlier stages of baldness typically seen in younger men, and side effects for them appear minimal: Rogaine can cause scalp irritation, while Propecia in rare instances can cause loss of libido. Women may use Rogaine, but if they are of child-bearing age they should not take Propecia because it may cause birth defects.

Eight in 10 Propecia users and one-third to one-half of Rogaine users find that it prevents or slows further hair loss. But only 10 percent of Rogaine users and 30 to 40 percent of Propecia users get what can be described as "cosmetically useful regrowth" of hair. Doctors often suggest combining the drugs to (possibly) improve the odds.

More potent drugs are under development, including a treatment that blocks two of the enzymes that convert testosterone into DHT. (Propecia inhibits a single enzyme.) In one trial, this experimental formulation reportedly suppressed DHT by 82 percent, compared with a 38 percent rate achieved by Propecia.

For those who don't want to wait for improved drugs, hair transplantation is an option. Experts agree that techniques have improved from the days when unsightly plugs of hair blossomed like oases on otherwise barren patches of scalp. But they differ on whether transplants -- which move hair follicles from one part of the scalp to another -- produce a look that's natural enough to be worth the expense, which can run into the tens of thousands of dollars.

None of the treatments mentioned so far will work for alopecia areata, a type of hair loss that stems from an autoimmune disease. With this condition, hair likely will reappear spontaneously in six months to two years. Scarring alopecia may look like hereditary baldness, but early treatment with medications can cure this condition.

Women, especially after menopause, are not immune to hair loss. By age 70, roughly 50 percent of women experience some hereditary hair thinning, compared with 80 percent of men. Dermatologist Laurence Miller of Chevy Chase says the toughest part of his practice is not being able to help women in their forties "who are losing their hair and we can't find out why."

Alternatives Are Minimal

There's nothing outside Western medicine that unquestionably works for the major forms of hair loss -- and certainly there's a dearth of U.S. studies to back up the efficacy of alternatives. Acupuncture is perhaps the most promising technique, based on medical literature and practice from China and on acupuncturists' reports. But even they concede that the ancient healing art likely wouldn't work for hereditary baldness -- if they were to offer it for this purpose.

Michael Arnold, a physician and acupuncturist in Pacific Grove, Calif., says hair loss usually is incidental to a reduction in the body's core vitality, described in Chinese medicine as a "kidney deficiency." If a patient says he is tired and losing hair faster than his father did, Arnold says he would treat the hair loss with acupuncture, herbs and lifestyle counseling. But in general he wouldn't treat hereditary balding, which he says is "just a trait, part of the genes."

Yet Xiaoming Tian, a licensed acupuncturist in Bethesda who is a clinical consultant to the National Institutes of Health and a member of the White House Commission on Complementary and Alternative Medicine Policy, says acupuncture can "do a very good job" for hair loss that is related to stress.

Tian says he often uses a small hammer-like device called a "plum blossom," whose seven tiny needles lightly stimulate bald areas on the scalp to improve blood flow. He also uses needles and acupressure on acupuncture points along the body's meridians, or energy channels, and he draws from an arsenal of Chinese herbs, including black sesame.

Bryan L. Frank, president of the American Academy of Medical Acupuncture, a group of medical doctors and osteopaths, has heard reports about benefits of acupuncture for hair loss. "But in my opinion," he says, "it's always been a little suspicious."