I'm pleasantly surprised with the power of my Vitamin C serum! I highly recommend the Banish Vitamin C serum or any serum with a high concentration of Vitamin C. The product I use claims to contain 99% Vitamin C but I'm sure that is a targeted incentive for consumers to buy the product. I read someplace that if a product claims such a thing, the rest of the ingredients are non-beneficial, harmful or something along those lines. Nonetheless, this serum that I've been using works wonders! Within three applications (I used one whole drop each time), it drastically shrunk one huge pimple! Even toothpaste and tea tree oil have never worked that well for me! An added bonus is the immense decrease in redness around the pimple. The mark left from a medium sized zit I had last week has virtually disappeared! As someone who has tried a ton of products to combat acne, I can't recommend Vitamin C enough(at a high concentration because the Body Shop Vitamin C serum which has a low concentration only had a small effect in comparison)!