Nick Burns writes about laser hair removal:
The products rely on plant extracts that interfere with the growth in the follicles that produce facial hair, manufacturers say. One common ingredient, saw palmetto, an extract of the dwarf palm tree, inhibits the enzyme responsible for converting the hormone testosterone into dihydrotestosterone, which regulates hair growth. “The funny thing is that saw palmetto actually promotes hair growth on the head,” said Tom Mammone, the executive director of research for Clinique. Blocking the hormone in the follicles on your face can slow hair growth, while having the opposite reaction if applied to the scalp, Mr. Mammone explained. Palmatine, a plant extract, is another common ingredient in hair-growth delayers. Its exact function is unknown, but product developers like Clarins suggest it slows the division of cells responsible for creating hair.
