It does a very good job. At first, I bought it for prevention and used it once a week, and we never had any issues. We left it for a quite long period out of negligence until two weeks ago when I noticed the visitors (lice). I immediately got the lotion, applied a sufficient amount, and started combing with the special comb that it comes with. To my surprise, the medication started to work very quickly. I left it on my daughter's hair (9 years old, hair length below the shoulders) for many hours, then washed it with shampoo, combed it again with the comb, and no lice came out. They all came out with the first combing using the lotion. The normal use is to shampoo first and then apply the lotion, but personally, the lotion leaves a greasiness on the hair and feels like a conditioner. It also has a slightly strong smell, but considering the results it provides, it is worth it. So, I use them in reverse order with equally good results. I highly recommend it and will definitely buy more once it runs out!