-Users of the glaucoma eyedrops Lumigan, also made by Allergan, found that one of the side-effects of the drops was longer, fuller and darker eyelashes.  However, in addition to fuller lashes, Latisse may permanently alter the pigmentation of the iris and cause darkening of the eyelid skin. 

It may also promote hair growth in other skin areas that it touches, so users will have to be careful to remove the product if it gets anywhere else on skin if they want to avoid growing hair there.-



The down side being the permanent pigmentation of the iris (especially for light colored eyes) and
the darkening of eyelid skin but I bet this could be helpful in growing thick eyebrows and improving
thinning hair.  Men may want to look into this.