S-adenosylmethionine, more commonly known as SAMe, was released in the U.S. only a year ago, but has already become the fourth most popular individual supplement in drugstore chains and retail stores. On the other hand, SAMe, pronounced Sammy, has been in use in Europe for over 20 years as a prescription drug for treatment of depression and arthritis. The few clinical trials done indicate that SAMe has, equal if not greater, therapeutic effects on depression as tricyclic antidepressants but with a more rapid onset and virtually no adverse side effects. Similarly, the limited trials performed with arthritis patients suggest that SAMe has anti-inflammatory and pain relief properties comparable to those of non-steroidal anti-inflammatory drugs but with the added bonuses of joint cartilage repair and minimal adverse side effects. Surprisingly, SAMe is not an exotic chemical; it is an endogenous molecule in the body which serves as the most potent methyl donor known. Methyl donation, an essential biological process, has interestingly been linked to the monoamine neurotransmitter metabolic pathway in ways comparable to conventional anti-depressants. Despite existence of only preliminary scientific evidence for SAMe's alleged beneficial effects, this dietary supplement has almost instantly become a favorite among the public. Several books and web sites dedicated solely to disseminating information about SAMe have already been developed. The increasing popularity of SAMe in the U.S. is alarming since the unregulated marketing nature of SAMe may cause severely depressed individuals or patients suffering from arthritis to self- medicate or substitute SAMe for their current medication resulting in potentially devastating consequences.