• DHT is a naturally occurring chemical that can lead to baldness.Bald man from backside image by TekinT from Fotolia.com
  
  Dihydrotestosterone, also referred to as DHT, is a natural metabolite produced by the human body. When androgen, a hormone that plays a significant role in hair loss, is metabolized by an enzyme and combines with testosterone, it creates DHT. This plays a major role in hair loss because it blocks certain receptors within hair follicles which prevents these follicles from receiving necessary nutrients. There are naturally occurring substances that act as DHT inhibitors, and some of these chemicals are found in certain shampoos.
  
  

Nizoral

• Nizoral is an over-the-counter shampoo that contains a naturally occurring chemical called ketoconazole, which has been shown to work as a weak DHT inhibitor. The recommended frequency of use for Nizoral is twice a week, in between use of your regular shampoo and conditioner. Nizoral is used mainly as a treatment for dandruff, ringworm and other fungal infections.
  
  

Revita

• Like Nizoral, Revita also contains the natural DHT inhibitor ketoconazole. Produced by DS Laboratories, Revita is considered a supportive shampoo with regard to combating hair loss. This means that it is not recommended as the sole cure for hair loss but rather as a shampoo to accompany other, stronger treatments. Revita is also an anti-fungal shampoo that can be used to help cure outbreaks of fungal infections, such as dandruff.
  
  

Revivogen

• Revivogen is an over-the-counter shampoo that contains natural ingredients that act as DHT inhibitors. Revivogen consists of several products used in succession. These products are the Scalp Therapy, the Bio-Cleansing Shampoo and the Thickening Conditioner. According to the Revivogen website, the shampoo works by blocking the androgen receptors, which prevents testosterone from entering cells. By preventing testosterone from entering cells and shutting down metabolizing enzymes, Revivogen prevents the metabolic process that creates DHT.