Vaniqa (pronounced VAN-i-ka) is a prescription cream applied to the skin for reducing unwanted facial hair in women ages 12 and older. For unknown reasons, Vaniqa does not work for everyone, and some insurance policies do not cover it.
This medication is not a depilatory, but rather appears to retard hair growth to improve the condition and the appearance of some consumers. You will probably need to continue using a hair-removal method (e.g., shaving, plucking) with Vaniqa. It usually takes 2 months to judge whether or not it is working. If you stop taking it, your hair may come back to previous levels within 2 months after stopping.
Vaniqa should not be used:
Hair growth cells and cancer cells share some interesting characteristics: rapidly dividing with multiple potentials for differentiation. This is one reason chemotherapy and radiation can result in hair loss: they disrupt the same kinds of cellular activity . It has been theorized that some cancer drugs may be used to induce a controlled amount of hair loss or reduction. Vaniqa's active ingredient, eflornithine hydrochloride, has antitumor activity . It is the first commercially available topical preparation to come out of this sort of research.
Vaniqa became available in the U.S. on July 31, 2000, and is made by Bristol-Myers Squibb in a partnership with Gillette.
Eflornithine hydrochloride inhibits an enzyme that affects hair growth in rats . Regulation of this enzyme, called ornithine decarboxylase (ODC), was later shown to reduce hair growth in mice  and sheep . Recent studies suggest that observations in certain types of mice may have parallels in humans [6, 7].
This drug has been found to be an astonishingly effective cure for some types of African "sleeping sickness," even able to cause a rapid and complete recovery in comatose patients . Clinical reports show that taking it orally to treat sleeping sickness can induce hair loss as a side effect .
One large published study on safety found the product rarely caused significant side effects such as acne, follicle irritation, itching, or dryness . This corroborates unpublished data submitted to FDA showing that about 2% of subjects discontinued use due to adverse reactions .
Unpublished data submitted to FDA observed about 58% of women using it on facial hair had improvement . This study suggests it may be particularly effective in postmenopausal women.
Proof of how hard it is to judge effectiveness
Perhaps the most striking result was how many women in the control group (who used cream with no active ingredient) were observed to have less hair. Of 201 patients, over one-third who used a placebo were assessed by physicians as either "improved" or "marked improvement."  This huge number of "false positives" means two things for consumers seeking hair removal:
That's why you should rely on large-scale controlled studies to determine wheyher a hair-removal product is effective.
Ms. James is a Chicago-based writer and consumer activist who owns hairfacts.com.