This stuff is phenomenal! This is my 3rd go-around on my brows over the last 4 years. You really do have to keep using it to maintain the growth, even every couple of days will work. Unfortunately I ran out and then over-plucked (sigh) so here I am again, haha. But man, it works REALLY well for brows, I never knew mine could be so full and lush, and after about 1.5 months so far I can already tell they're filling in. I added in the lash serum for the first time, it's harder to tell with those yet, but given my brow success, I'm confident it will work. Awesome formula, thanks Nulastin!