Q & A: Uncovering mineral makeup and eyelash-growing products

Key Points

Q. What is the active ingredient in eyelash-growing products?

A. One of the most interesting cosmeceuticals to enter the marketplace in 2006-07 was a liquid eyelash conditioner claiming to create the appearance of thicker, fuller eyelashes. While the appearance claim was clearly cosmetic, the mysterious liquid was actually shown to grow eyelashes more quickly than control. Closer inspection revealed that the cosmeceutical contained a drug used to lower intraocular pressure in glaucoma patients known as latanoprost. Latanoprost lowers intraocular pressure by increasing PGE2 levels, and is one of the most popular glaucoma drugs used by ophthalmologists. Minoxidil also boosts growth of scalp hair by lowering PGE2 levels. It should come as no surprise to dermatologists that latanoprost was found to promote growth of eyelashes in individuals using the eyedrops for glaucoma, who accidentally placed the liquid at the base of the hairs.

When it was discovered that the highly effective cosmeceutical was actually a drug, the Food and Drug Administration seized the product and the company voluntarily withdrew the product from the marketplace. The company that owns the patent for latanoprost also sued for removal, and is currently conducting trials to determine whether to pursue an indication for eyelash growth.

A. The current "natural" and "green" marketing push has created interest in a line of cosmetics known as "mineral" makeup. While the term "mineral makeup" has no true meaning, it has come to represent a line of powder cosmetics for facial application. The powders are formed from ground talc and pigments designed to impart color and shine to the face, cheeks and eyelids. The cosmetics are dusted over the face with a self-contained brush or from a compact with an external brush.

These mineral cosmetics have been touted to be more natural, less allergenic and more appropriate for sensitive skin than their liquid counterparts. I am not sure that any cosmetic is "natural," but the powder formulation does contain fewer ingredients and may be statistically less allergenic as a result. The absence of any water also allows the preservative concentration to be lowered and eliminates the need for emulsifiers, a common source of skin irritation. Thus, it is probably accurate to argue that these products are less likely to cause irritant and allergic contact dermatitis.

The only problem with the mineral cosmetics is the short longevity of the powder on the skin. Liquid cosmetics leave behind a thin film that sticks to the skin surface once the volatile vehicle has evaporated. The powder cosmetics can be dusted on and easily rubbed off the face. One way to improve their longevity and photoprotective capabilities is to apply the powder immediately after applying sunscreen or a sunscreen-containing moisturizer. The powder cosmetics will increase the SPF of the underlying sunscreen.

Zoe Diana Draelos, M.D., is a Dermatology Times editorial adviser and investigator, Dermatology Consulting Services, High Point, N.C.

Questions may be submitted via e-mail to zdraelos@northstate.net.