Tretinoin

Tretinoin (trade name Retin-A or Renova) is a topical cream or gel that may influence improvement in cell development, making it beneficial for many skin-care problems ranging from acne to wrinkles. Surprisingly, no one is actually sure why tretinoin can do that, but there are lots of studies indicating that it does. Some dermatologists have begun formulat­ing their own treatments for male pattern balding by mixing tretinoin with minoxidil for topical application. It is thought that tretinoin can increase the absorption of minoxidil into the scalp. However, subsequent research has disproven tretinoin to have any effect at all either by itself or in combination with minoxidil (Source: American Journal of Clinical Dermatology, 2007, pages 285-290)