I got Latisse and I swear I noticed a difference in the first two days because eyelashes that would have fallen out, didn't. Latisse works by extending the growth cycle of the eyelash, which is what happened with me.
I have been using it for four weeks only, and I am so happy with the results. My lashes are already longer (they started getting noticeable in the first week...noticeable to me) and I even put it in my eyebrows, and they have gone from sparse to a bit thicker.
I am 41 and had been noticing my eyelashes falling out a lot, and my eyebrows getting sparse. Now my lashes and brows are restored to how they were in my 20s, and even better.
Can't wait to see how it is after the suggested sixteen weeks (for full results).