The Role Of Testosterone In Humans
The testosterone hormone is an androgen found in men and women. In men, testosterone regulates fertility, red blood cell distribution, muscle mass, and fat distribution. Women’s ovaries produce testosterone in small amounts. It combines with estrogen (the female sex hormone) to help with the growth, repair, and maintenance of the reproductive tissues and bone mass. Testosterone also impacts scalp hair growth in both men and women. Let’s find out how in the following sections.
Effect Of Testosterone On Hair Growth In Men
DHT or dihydrotestosterone, produced by testosterone and the enzyme 5-alpha reductase, causes hair loss in specific areas of the scalp and controls hair growth in androgen-sensitive areas in older men (1). Androgenic sensitivity in the scalp causes the hair follicles to shrink, leading to androgenic alopecia. You may notice balding on the frontal hairline, vertex, and complete balding.
Effect Of Testosterone On Hair Growth In Women
The role of androgens, especially testosterone, in female pattern hair loss is not clear (2). Female pattern hair loss is more likely to be caused by androgen metabolites like Di Hydro-epi-androsterone (DHEA) and androstenedione (1). Androgenic alopecia in women occurs mostly in the parietal area. Some women may experience excess hair growth due to androgen production, and the condition is called hirsutism. It affects close to 5% of women (1). Traditionally, testosterone takes most of the blame for hair loss. But research suggests that the active androgen DHT is to be blamed (3). Androgens regulate hair growth not only on the scalp but also on the entire body.
How Testosterone And Androgens Regulate Hair Growth
The hair follicles contain unique genetic codes (1). These codes regulate when, on which body part the hair will grow or fall, and what triggers will cause that. These genetic codes decide which part of the body will be androgen sensitive. In other words, even if your androgen levels are normal, androgen sensitivity may cause hair loss. DHT or dihydrotestosterone, an androgen and a byproduct of testosterone through the enzyme 5-alpha reductase, causes hair loss (4). A rise in androgen levels during pregnancy may also cause telogen effluvium (excessive hair fall) in postpartum women. During pregnancy, there is a variation in androgen, estrogen, and prolactin levels. (5). After the delivery and when the placenta is removed, these hormone levels normalize. Such drastic changes in the hormone levels, coupled with stress (both physical and mental), cause postpartum hair loss, which is noticed a few weeks after delivery. Hyperandrogenism in women also impacts their skin and hair growth. Androgen imbalance, especially testosterone production, can cause hirsutism in women. This condition is marked by excessive hair growth in a male-like pattern. Other than the hair growth, androgens can also affect the entire hair cycle. Scroll further to understand how.
Understanding Androgens And The Human Hair Growth Cycle
The hair growth cycle has four stages:
Anagen (growth phase) Catagen (regression phase) Telogen (resting phase) Neogen/Exogen (when the hair falls out and new growth starts
Androgen levels can interrupt this cycle at any time and cause hair loss.
High Testosterone Vs. Low Testosterone
Low and high androgen levels can cause the hair follicles to stop growing new hair shafts (6). This prevents hair growth but allows old hair to fall out, causing pattern hair loss. The connection between testosterone levels and hair loss in men and women varies. Men incur hair loss when there is an overproduction of the DHT hormone. Research shows that women with low or high androgen levels have hair growth issues. While excess androgen may cause excess hair growth in women, a study found that serum testosterone levels are lower in women experiencing hair thinning (7) (3). Abnormal androgen levels may also cause androgenic alopecia.
Androgenic Alopecia
Androgens also cause androgenic alopecia or female pattern hair loss in genetically susceptible women. This pattern of hair loss in women occurs because of the genetic predisposition of androgenic sensitivity in hair follicles. Testosterone replacement therapy is a common treatment option for testosterone-related hair loss. But, does it trigger hair loss?
Does Testosterone Replacement Therapy(TRT) Cause Hair Loss?
No. It is a misconception. In this therapy, testosterone is administered in the form of injections. Research shows that TRT does not cause hair loss. Rather, TRT or Androgen Replacement Therapy promotes hair growth in androgen-deficit women (8) (3). It is unlikely that you will experience hair loss while undergoing TRT. However, if you experience hair loss when on therapy, here is what you need to do.
What To Do If You Experience Balding When Trying TRT
Hair loss is a complex process and is caused by multiple underlying factors like insulin resistance, diabetes, and obesity. These factors can increase 5-alpha reductase in your body, triggering the conversion of testosterone into DHT. This may cause hair loss (8). Other than these, age, alcohol consumption, medication, and sedentary lifestyle may also lower testosterone and increase DHT. These factors may contribute to hair loss while you are undergoing TRT (8). This is why it is crucial to consult your doctor before starting TRT. They will determine whether you are fit to undergo the therapy or not. In case you have experienced hair loss during TRT, the doctor may suggest discontinuing TRT. They may also suggest a few other treatment options.
How To Treat Hair Loss Due To Testosterone
In Men: The doctor may suggest using finasteride to manage androgenic alopecia or male pattern hair loss. An optimal dose of 1 mg/day can treat male pattern hair loss (9). In Women: Anti-androgens like cyproterone-acetate and topical minoxidil are effective in treating female pattern hair loss (2). There are various non-surgical treatment options available, such as mesotherapy, platelet rich plasma therapy, and hair growth factor therapy, to improve circulation in the scalp and stimulate hair growth. Hair transplant is a surgical procedure usually considered in the advanced stages of hair loss. The grafts of hair roots from the back of the head are implanted into the thinning areas in the front and vertex, which grow naturally in 6 to 8 months.
Examine the link between hair loss and low testosterone with this video. Watch it to find out the science behind it, and determine whether this hormone imbalance is associated with hair loss. How can I regain testosterone? A balanced diet, regular exercise, and nutrient supplementation can help restore the normal levels of testosterone. Do tall guys have more testosterone? There seems to be no link between testosterone and height. Does zinc increase testosterone? Yes, zinc supplementation has been shown to improve serum testosterone levels (10). Do omega-3 fatty acids increase testosterone? Yes, omega-3-rich foods like fish have been shown to help improve testosterone levels (11). Does vitamin D raise testosterone? Yes, studies have shown that testosterone levels may increase with vitamin D supplementation (12).
