Its been around for awhile and I think it was approved for use in Australia to help PREVENT skin cancer in fair-skinned people. The thing is, you need to get some sun exposure or tan in tanning beds to get good results, so I think the cancer prevention gets cancelled out for our purposes. There are no known long term negative side effects as far as I know. The sides effects are basically: 1) Your freckles get darker before the rest of your skin catches up, 2) Some nausea/appetite suppression, 3) Increased libido. Obviously not all of those sides are bad!