The Thick and Thin of Hair Cosmetics

While Finasteride and minoxidil-based products are giving consumers hopes of regrowing hair, another part of the hair-care industry has been jumping into the fray.

Drugstore chains, beauty shops, and salons are offering a number of products claiming to make hair appear thicker or fuller. While they won't solve baldness, such products can help women in particular by giving the appearance of more hair--if, and only if, the products are used regularly.

A quick walk down the store aisle shows a multitude of shampoos, conditioners, gels, mousses, and volumizers competing for your dollars. Many labeling claims target people with thinning hair, while others hint they can regrow hair, creating controversy about whether such a claim constitutes going too far. Any product claiming to regrow hair would have to file a new drug application.

Many of these products seem to thicken hair by coating it with chemicals called polymers. Hair has a negative charge, and the polymers' positive charge causes the polymers to adhere to the hair shaft, resulting in better hair manageability and shine. The hair also retains moisture, causing the shaft to swell and its diameter to expand slightly.

If you're one to use bleach (peroxide) occasionally, he says, the bleach can achieve that sliding effect. Perms also make your hair wavier and fuller looking.

Many promoters of these products say their pro-vitamin B5 (panthenol) formulas can lead to fuller hair. But  the claim has never been proved.