The enzyme 5 alpha reductase converts testosterone into dihydrotestosterone (DHT) and it is DHT that is most potent androgen in promoting androgenetic alopecia – the medical term for male pattern balding and Female Balding. The enzyme was first discovered in the male prostate where it catalyzes the conversion of testosterone to dihydrotestosterone, which in turn binds to the androgen receptor and initiates development of the external genitalia and prostate, and is also responsible for prostate enlargement.
Later, 5-alpha reductase was also found in human scalp hair follicles and elsewhere in the skin, where it carries out the same reaction as in the prostate. It is thought that disturbances in 5-alpha reductase activity in skin cells might contribute to male pattern baldness, acne, or hirsutism.
There are at least two 5 alpha reductase isoenzymes, type I and type II. They are active in different regions of the body, but they both produce DHT that can circulate throughout the body and exert effects in organs other than that where the DHT was produced.
There are two types of 5 alpha reductase enzyme each coded by a separate gene and each produced by different tissues, the genes for 5-alpha reductase has been mapped to chromosome 5. Although both may be important in pattern baldness development, type I 5 alpha reductase may be more important because it is highly active in scalp skin and hair follicle sebaceous glands. It produces 60% to 70% of the total DHT in our bodies. Type II produces the remaining 30% to 40% of DHT.
It has been observed that levels of type II 5 alpha reductase in the outer root sheath of scalp hair follicles is less as compared to Type I so it is believed that local activity of both type I and type II 5 alpha reductase which contributes to androgenetic alopecia development.
Most of the medications used for DHT induced hair loss are 5 alpha reductase inhibitors. Finasteride is only a type II 5 alpha reductase inhibitor and so can only reduce DHT levels by at most 70%. Dutasteride is believed to block both types of isoenzymes and in principle may be a more effective treatment – though studies have not been conducted to demonstrate the efficacy of Dutasteride for androgenetic alopecia.
Some experimental dual type I and type II 5 alpha reductase inhibitors have been shown to reduce DHT levels by up to 95% after a single oral dose. The discovery of a plant homolog of human 5-alpha reductase may lead to new drugs, and the race is now on to find more inhibitors of 5-alpha reductase. There are many plant sources or herbs which have properties to inhibit the enzymes.
Gamma Linolenic Acid (GLA), Alpha Linolenic Acid (ALA), Linoleic and Oleic Acid are essential fatty acids found in plant oils. These fatty acids have been individually proven to inhibit 5-Alpha Reductase. In fact these are the most powerful inhibitors of 5-Alpha Reductase known today. Not only do they inhibit the Type II form of the 5-Alpha Reductase which other products like Propecia® inhibit, but also the Type I form of the enzyme which is present in high concentrations in the scalp, sebaceous glands, and the skin. Additionally GLA, ALA and Oleic acid have potent anti-inflammatory properties.
There are many plant sources like Borage Oil and primrose oil which are known to contain gamma linolenic acids and alpha linolenic acids and are used as Natural Herbal Remedies for hair loss.
Azelaic acid is a naturally occurring dicarboxylic acid found in whole grain cereals, rye, barley and animal products. It is FDA approved as a topical preparation for the treatment of acne and it is effective against a number of other skin conditions when applied topically. There is strong scientific evidence that Azelaic Acid and Zinc are potent inhibitors of 5-Alpha-Reductase. When Azelaic acid, Vitamin B6 and Zinc Sulfate were added together at low concentrations, 90% inhibition of 5 Alpha-Reductase activity was obtained. The synergistic activity of these compounds against 5-Alpha-Reductase makes this combination potentially a very effective hair growth formula for treatment of Male Pattern Baldness.
Many companies every now and then churn out new natural hair growth formulas by combining GLA, ALA, Linoleic Acid, Azelaic acid, Vitamin B6, Zinc Sulfate and Saw Palmetto extracts. These ingredients work through different mechanisms to synergistically inhibit both type 1 and 2 forms of 5-Alpha Reductase and decrease DHT locally. By decreasing the DHT levels, hair follicles can grow and thicken naturally, leading to a fuller, healthier scalp without the side effects associated with synthetic medications.