T/Gel is a medicated shampoo

Shampoo

Shampoo is a hair care product used for the removal of oils, dirt, skin particles, dandruff, environmental pollutants and other contaminant particles that gradually build up in hair...

 produced by Neutrogena

Neutrogena

Neutrogena is an American brand of premium-priced skin care, hair care and cosmetics, that is headquartered at Los Angeles, California. According to product advertising at their website, Neutrogena products are distributed in more than 70 countries....

. It reduces psoriasis

Psoriasis

Psoriasis is an autoimmune disease that appears on the skin. It occurs when the immune system mistakes the skin cells as a pathogen, and sends out faulty signals that speed up the growth cycle of skin cells. Psoriasis is not contagious. However, psoriasis has been linked to an increased risk of...

, dandruff

Dandruff

Dandruff is the shedding of dead skin cells from the scalp . Dandruff is sometimes caused by frequent exposure to extreme heat and cold. As it is normal for skin cells to die and flake off, a small amount of flaking is normal and common; about 487,000 cells/cm2 get released normally after...

, seborrheic dermatitis, and DHT

Dihydrotestosterone

Dihydrotestosterone is an androgen or male sex hormone. The enzyme 5α-reductase synthesises DHT in the prostate, testes, hair follicles, and adrenal glands...

 levels. It has a limited antiandrogen

Antiandrogen

Antiandrogens, or androgen antagonists, first discovered in the 1960s, prevent androgens from expressing their biological effects on responsive tissues. Antiandrogens alter the androgen pathway by blocking the appropriate receptors, competing for binding sites on the cell's surface, or affecting...

 effect, and is used by some people to slow hair loss. In Merck

Merck & Co.

Merck & Co., Inc. , also known as Merck Sharp & Dohme or MSD outside the United States and Canada, is one of the largest pharmaceutical companies in the world. The Merck headquarters is located in Whitehouse Station, New Jersey, an unincorporated area in Readington Township...

 studies to determine the effectiveness of Propecia as a hairloss treatment for FDA approval, all subjects were required to use T/Gel in order to standardize everyone's shampoo regimen and to prevent seborrheic dermatitis from interfering with potential scalp regrowth.
Its primary active ingredient is coal tar

Coal tar

Coal tar is a brown or black liquid of extremely high viscosity, which smells of naphthalene and aromatic hydrocarbons. Coal tar is among the by-products when coal iscarbonized to make coke or gasified to make coal gas...

. There is debate about coal tar as a carcinogen and T/Gel shampoo may be labeled as such in CA (http://www.hairlosstalk.com/newsletter/article109.htm)

Drug Facts: 2% Neutar Solubilized, Anti-dandruff. 0.5% Coal Tar Extract, Anti-seborrheic dermatitis, Anti-psoriasis