Almost everyone desires to have healthy looking hair for which taking good care of hair becomes very essential. Today, hair loss or androgenic alopecia affects most of the men and women worldwide. Men face problems of hair loss more than the females. The three things involved in hair loss are genes, hormones and age. Among the hormones, testosterone is the key hormone responsible for hair loss. Let us have a detailed understanding about the link between testosterone and hair loss.
Overview of Testosterone and Hair
Testosterone is a steroid based hormone found both in men and women. In men, it is produced in testes and in small amounts in the adrenal gland. Its production from testes is controlled by the hypothalamus and pituitary gland. Testosterone has an important role in the male reproductive system and promotes secondary male characteristics such as muscle growth and hair growth on the body. Testosterone is present in body in two forms as the free form and bound form. When associated with protein albumin or sex hormone binding globulin (SHBG) it is called as the bound form. The free form is readily available to act within the body.
In males, testosterone is converted by the enzyme 5-alpha-reductase to Dihydrotestosterone (DHT). In women, DHEA chemical gives rise to DHT. This particular hormone is found in skin, hair follicles and prostate gland. DHT is five times more potent than testosterone.
Link between Testosterone and Hair Loss
Since more men suffer from hair loss problems, it has been associated with testosterone. However, this has not yet been proved by any research study. It is actually not the amount of testosterone but the sensitivity of the hair follicles that is responsible for hair loss which is usually determined by the genetics of a person. The Androgen Receptor (AR) gene makes the receptor on hair follicle, which interacts with hormone DHT, sensitive. When the receptors on these hair follicles are sensitive to DHT, then the hair loss occurs more easily. Thus, it is the genetics that governs the hair loss. Especially, when young men suffer from baldness, it is observed to be hereditary in their families. Thus, male pattern baldness is an inherited trait.
Females too go through androgenic alopecia. Although women have much low levels of testosterone as compared to men, the amount present is sufficient to cause hair loss. The female pattern of hair loss (FPHL) is due to the action of DHT on hair follicles.
How Does Testosterone Influence Hair Loss?
The process in which testosterone affect hair loss is sequential which are as follows:
- The testosterone transforms into DHT, which acts on the hair follicles of the scalp.
- The affected hair follicle becomes smaller.
- Each new hair grows for a lesser time than the normal time of three years.
- Gradually, all that remains is the smaller hair follicle. It leads to very thin hair which does not grow out to the skin surface.
- Slowly, hair growth completely stops. In some cases, since the hair follicle remains alive, hair regrowth is possible if proper treatment is done on time.
Patterns of Hair Loss
Hair on the body comes out from the tiny pouches under the skin surface which are called as hair follicles. Each hair normally grows from a hair follicle for about three years. After its complete growth the hair is shed and a new hair starts growing from the follicle. This cycle of hair growth and shedding takes place throughout the life of an individual. Hormonal changes, age, and stress can bring out changes in this hair growth cycle. Loss of hair is often experienced due to shrinkage of hair follicles or sensitivity of hair follicles to DHT or testosterone. This has impact on the growth cycle of the hair. Although new hair grows, it is thin and eventually becomes thinner. Till a stage is reached where there's no hair left and follicles becomes dormant. This gives rise to baldness. The hair follicles are present but they can no longer perform their function.
Baldness affects most of the men by the age of 45 years. The male baldness develops in a particular shape called as Male pattern baldness (MPB). First the frontline recedes at the sides to form an M shape. Along with this the crown of head loses hair too. The two areas join to form a U shape. The chest hair is observed to become thin in texture.
Women too experience hair loss of a different pattern. The hair starts becoming thin over the top of the scalp in a 'Christmas tree' pattern. However, the front hairline does not recede. Telogen Effluvium and alopecia areata are the two most common hair loss types that women suffer from. Among these, Alopecia areata is more common.
Treatment for Testosterone Linked Hair Loss
Most of the treatment procedures for treating baldness in men and women are involved with interfering with action of testosterone and DHT hormones. However such treatments need to be used with caution since they cause sexual side effects in both genders. Further, there is no guarantee of how long such treatments need to be continued and if they would be successful.
Other treatment options which do not interfere with mode of action of hormones include:
- Minoxidil topical products
- Ketoconazole lotions
- Laser treatment
- Surgical hair follicle transplant.
The research studies on hair loss have revealed that it is not the amount of circulating testosterone but the level of DHT binding to the hair follicle receptors of scalp that cause the problem of hair loss. Further, men suffering from early male pattern baldness have hereditary genes that are hypersensitive to DHT. Although treatments are available, one needs to choose the therapy which will cause no/less side effects.