MSM stands for Methylsulfonylmethane. Its a natural form of sulfur. It has been shown to decrease the action of DHT on the hair follicles (which causes hair loss/shedding in both men and women). Rogaine, Progaine and other hair restoration products contain meds that combat DHT, which stands for dihydrotestosterone.
DHT is the primary contributing factor in male-pattern baldness. Female-pattern baldness is more complex, and DHT is only one of many causes of women's hair loss, as we know.
Methylsulfonylmethane (MSM), is an organosulfur compound with the formula (CH3)2SO2. It is also known by several other names: DMSO2, MSM, methylsulfonylmethane and methyl sulfone. [1] This colourless solid features the sulfone functional group and is considered relatively inert chemically. It occurs naturally in some primitive plants and is present in small amounts in many foods and beverages and it is marketed as a dietary supplement, although its benefits are disputed. (<- this paragraph sourced from Wikipedia)
You may purchase/find MSM anywhere quality dietary supplements and vitamins are sold. Commonly combined with glucosamine and chondroitin in joint supplements, it is also marketed alone. I take plain MSM for my hair and joints. I bought mine at Wal-mart (Spring Valley brand) and its about $6-7 for a bottle of (100) 1000mg capsules. I only take 1 a day. Organically, you can find sulfur in many foods like fish, eggs, onions/leeks, etc. Hope that helps!
Sorry OP, didn't mean to hi-jack the thread, just answering a question!