So, how DO you treat hair loss, then?

Some problems of hair loss, such as those that come from menopause and other changes in the body's hormone levels, can be treated with hormone therapy. Drugs such as minoxidil can help too. There are surgical options -- although receiving a hair transplant from someone else can carry the same risks of complication and rejection as any other transplant surgery. And there are always hairpieces and wigs, some of which can be attached semi-permanently. Cruelly, some hair replacements can themselves cause hair loss [source: AHLA].

MSM and Hair Growth

Because MSM helps in tissue repair, some sellers tout it to promote the growth of hair and nails. After all, hair and nails are dead skin cells -- the more cells you produce, the more dead cells you have, right? Some physicians even say that MSM helps your body build collagen, the protein that keeps skin and hair supple [sources: Josephs].

Well, collagen is definitely important. It's one of the body's most plentiful proteins. It strengthens the skin, the tendons, the internal organs -- even the teeth and bones. Collagen deficiency leads to the symptoms of scurvy, in which the body can't repair even minor injuries [source: Goodsell]. And yes, the production of collagen does seem to depend in part on dietary sulfur. In animals, at least [source: Brown].

But there haven't been any peer-reviewed studies conclusively linking MSM supplements to increased hair growth. Similarly, there is indeed sulfur in keratin, one of the main proteins of hair, but an ordinary diet is probably adequate to provide all the sulfur you need for everyday hair growth [source: Nix].

Obviously, there's a giant demand for an over-the-counter remedy for hair loss. Lots of us want to grow more hair. Plenty of conditions -- alopecia, menopause, stress and plain old hereditary baldness -- can lead to hair loss. Even some otherwise desirable prescription drugs, such as cancer treatments, cause hair loss.

Unfortunately, this means that plenty of unethical profiteers have been eager to tout anything in pill form as the scalp equivalent of garden fertilizer. The American Hair Loss Association notes that 99 percent of hair loss remedies just don't work - and for now at least, it counts MSM among them.

On the next page, we'll take a look at the ways MSM might be able to aid in repairing other tissues.