It’s very common for men to experience hair loss as they get older. Many people have heard that bald men have higher testosterone level. Is this true? Is there a link between balding and testosterone levels?
What hormone causes hair loss in males?
The medical term for male-pattern balding is androgenetic alopecia. Because this is generally experienced only by men, many people assume that high testosterone causes hair loss. It’s actually caused by a particular form of testosterone known as dihydrotestosterone, or DHT. There’s an enzyme called 5-alpha-reductase that converts testosterone to DHT.
DHT acts on various tissues in the body, including the hair follicles. It shortens the growth phase of the hair cycle and lengthens the resting phase. This means that each hair isn’t able to grow as long, and can fall out very easily during the long resting phase. DHT also miniaturizes the hair follicles, so that the hairs become finer and thinner, more like the “peach fuzz” hairs that cover an infant’s body. Eventually, DHT can make the growth phase of the hair cycle so short that the hairs don’t even poke through the scalp before they fall out.
Does testosterone cause balding?
There are differences in how sensitive the hair follicles are to DHT. This is largely determined by genetics. Some men with high DHT levels will not experience balding, while others with lower DHT levels will experience this. The age at which men start to notice hair loss can also vary widely, largely based on how sensitive the hair follicles are to the effects of DHT.
Studies have shown that there isn’t a link between a man’s natural testosterone levels and his likelihood of experiencing androgenetic alopecia. Instead, the likelihood of balding is believed to be attributable to differences in the sensitivity of the hair follicles to DHT, rather than differences in the levels of testosterone and DHT.
In men who are genetically susceptible to androgenetic alopecia, taking supplemental testosterone can accelerate the process of balding, by raising the levels of DHT. However, in men who are not genetically prone to having this problem, taking testosterone will not cause it to happen. The sensitivity of the hair follicles to DHT determines whether taking extra testosterone will contribute to balding.
Can high testosterone cause hair loss in women?
Women who have high levels of androgens (including testosterone and DHT) can experience hair loss. Usually, the pattern of hair loss will be different in women than in men. While men typically have hair loss at the front of the scalp first (a receding hairline) and then on the crown of the head, the hairline is usually preserved in women. Instead, women tend to experience hair loss around the central part of the top of the head. The thinning spreads outwards, leading to much thinner hair on the top of the head. Taking testosterone can sometimes trigger this pattern of hair loss in women. Again, there’s a genetic component to how sensitive a woman’s hair follicles are to DHT.
Does hair grow back after stopping testosterone?
Taking testosterone can lead to hair loss in some people. These effects may be partially reversible, although some hair loss can be permanent. The longer you’ve been taking testosterone, the less likely the effects are to be reversible.
Low testosterone levels can lead to a variety of symptoms in both men and women. However, it’s important to recognize that if you’re taking a testosterone booster, hair loss can result, and it can also cause more serious health issues like an increased risk of heart disease. You should not start taking extra testosterone without first testing your levels to see if they’re low, and your testosterone replacement therapy should be monitored by a medical professional to ensure that it’s safe and effective for you.
You can go to your own doctor in person and then go to a laboratory to get blood drawn for a testosterone test. You’ll then need to visit your doctor regularly for monitoring of your treatment. Alternatively, you can order a home testing kit and send in a blood sample collected through a fingerprick. If you choose home testing and your levels are abnormal, you will generally be able to have an appointment with a medical professional by telemedicine to discuss treatment options.
Sources
Biochemistry, Dihydrotestosterone. National Institutes of Health. https://www.ncbi.nlm.nih.gov/books/NBK557634/. Accessed 23 May 2022.
Hair Loss. Harvard Medical School. https://www.health.harvard.edu/a_to_z/hair-loss-a-to-z. Accessed 23 May 2022.
Kische H, Arnold A, et al. Sex Hormones and Hair Loss in Men From the General Population of Northeastern Germany. JAMA Dermatol. 2017 Sep;153(9):935–937. Doi: 10.1001/jamadermatol.2017.0297
