I was only using it on a regular basis for about three months. It did thicken many of my individual hairs, but not to some crazy extent. I stopped using it regularly out of sheer laziness, so I can't comment on any possible regrowth, but I am going to begin with it again. Be careful about using big amounts though. I think it was 1-3 mL, anything above that causes hypertrichosis and thickening of all old hairs. I took 5 mL per day, and transformed into a gorilla over the summer. On a positive note, I am now a good candidate for a body hair transplant.