It started out as a medicine, a prosaic treatment for glaucoma. Now it is being used for its cosmetic effects, promising to turn women into doe-eyed beauties within days.
The drug firm Allergan – the £1.5bn global company behind Botox – believes that Latisse could be worth millions worldwide. It was originally used to treat glaucoma, but scientific studies showed that, as a side effect, it made users' eyelashes longer. The company expects it to be approved by the US Food and Drug Administration shortly and to have it on shop shelves in the UK next year.
Longer lashes are a lucrative industry, with sales of mascara and other eye products estimated to reach £360m this year in the UK alone.
From the luxurious £5,000 mink and fox fur false eyelashes favoured by stars such as Madonna, Jennifer Lopez and Beyoncé to the vast array of high-end cosmetics claiming to lengthen, thicken and define eyelashes, increasingly extravagant measures are available to consumers wanting to highlight their eyes. Huge financial rewards await the company that markets a successful product, and these have already prompted fierce courtroom battles between drug and cosmetic companies.
To protect its anticipated bonanza, Allergan last year sued seven cosmetics companies for copyright infringement after they sold eyelash enhancing products containing Latisse's active ingredient, prostaglandins.
Valerie Randall, professor of biomedical sciences at the University of Bradford, said: "I imagine there will be a massive market for it. What the company is doing now is amplifying the side effects of a medical treatment. When we understand better how it works, it could be used in the treatment of alopecia and other hair growth problems."
Eyelash enhancers are just the latest example of an increasing crossover between cosmetics and medicine. Regaine, a treatment for male-pattern baldness, started life as a blood pressure drug; Botox was first used by doctors to treat eye squints and facial tics.
Patients are increasingly looking for non-surgical methods to tweak their looks, but with extreme remedies such as snake venom face cream on offer, the scalpel may look more appealing.
Beauty treatment: The side effects that paid off
Botox The wrinkle-busting drug, derived from the poison botulinum toxin, was originally used to treat spasms in the face and neck region. Doctors noticed that patients so treated also lost their wrinkles, and it is now the most popular anti-ageing treatment in the world.
Regaine The active ingredient in this treatment for baldness was discovered as a side effect of a medicine used to treat high blood pressure. Patients taking Minoxidil noticed that they experienced greater hair growth. Doctors found that it increases the supply of blood and nutrients to hair follicles.