It is recommended for the upper lash line only because there is some transference of the product to the lower lash line, every time you blink. This allows one bottle to last longer. It also reduces the risk of undesirable side effects when limiting usage, particularly dryness and itchiness.Latisse is only FDA approved for the eyelashes, however there are reports that it can achieve an improvement for brows as well.
There’s a longer explanation possible here, but the short version is this: the FDA has only approved LATISSE® to be marketed for use in the upper lashes. That being said, I am sure that some patients (and some doctors) have experimented with "off-label" uses of LATISSE® like thickening the eyebrows or lower lashes. Some of them have probably seen positive effects, too. That being said, though, it’s important to understand that LATISSE® has only been studied and approved by the results of clinical trials for use on the upper lashes, and there’s little information about the effects of using it elsewhere.
Wondering if Latisse can be applied on areas other than the upper lashes? The mechanism by which Latisse works suggest that it would work on any hair follicle on the body. However, not all hair follicles on the body (eyebrows, eyelashes, beard, scalp, etc) have the same physiology leading to patterns of loss that differ and may make the formulation that works on upper lashes ineffective elsewhere. Latisse was evaluated for and FDA approved for use on the upper lashes only. Notwithstanding, I have personally seen patients independent of recommendations, apply Latisse to lower lashes and eyebrows and see some improvements.
