A few months ago an esthetician at a skin care office recommended the obagi system to me a couple months ago for age spots on my cheeks. The program had retin-a, 4% hydroquinone and alpha hydoxhy acids. I didn't have any problems until I applied the hydroquinone. Immediately the lymph nodes in my neck became inflammed. I thought it was a fluke, waited a few days doing just the retin-a and alpha hydroxy, then applied it again. Same thing occured. I tried it ONE MORE TIME after a week's rest. Not a fluke at all, clearly a toxic substance. I then went online, which is what I should have done before shelling out almost $200 for this skincare line and read up on the hydroquinone. Happens to be banned in Europe, Australia and Japan because, quite simply, it's carcinogenic! Tied to leukemia in rat studies. The FDA wanted to ban hydroquinone a few years ago but came under sooo much pressure from dermatologists that so far, nothing. Apparently these skin "specialists" make an enormous amount of $ from selling it in packages like the obagi system. So the short of this story is, please be careful (not stupid like me) and research any products before you are talked into them by your doctor. That said, I am trying the grapefruit seed extract now!