Hair loss is a common problem affecting millions of people worldwide, and it can significantly impact a person’s self-esteem and quality of life.
Androgenetic alopecia (AGA), also known as male or female pattern baldness, is the most common form of hair loss, affecting up to 70% of men and 40% of women at some point in their lives[1][2].
While the exact cause of AGA is not fully understood, research has shown that testosterone and its byproduct dihydrotestosterone (DHT) play a crucial role in the development of this condition[3][4][2].
Key Takeaways:
- DHT is the primary androgen involved in AGA, with DHT concentrations being higher in men with AGA[1].
- DHT binds to the androgen receptors in hair follicles, causing them to shrink and eventually stop producing hair, a process known as follicular miniaturization[2][3][4].
- Genetics and androgens both play key roles in causing androgenic hair loss[5].
- AGA affects approximately 80% of Caucasian males[1].
- Other therapies for AGA include laser therapy, scalp microneedling, hair mesotherapy, and hair transplantation[1].
What is Androgenetic Alopecia?
Androgenetic alopecia is a frequent cause of hair loss in both men and women.
This form of hair loss affects an estimated 50 million men and 30 million women in the United States.
Androgenetic alopecia can start as early as a person’s teens and risk increases with age; more than 50 percent of men over age 50 have some degree of hair loss.
In women, hair loss is most likely after menopause.
AGA is caused by the miniaturization of hair follicles, which results in thinner, shorter, and less pigmented hair.
Other types of hair loss may result in complete hair loss or the formation of bald patches [2][1].
The Role of Testosterone and DHT in AGA
Testosterone is a hormone that is present in both men and women, but it is more abundant in men.
It is responsible for the development of male sexual characteristics, such as a deeper voice, increased muscle mass, and facial hair growth.
Testosterone is also converted into DHT by the 5-alpha reductase enzyme, which is present in hair follicles[3][4].
Studies have shown that DHT is the primary cause of AGA.
DHT binds to androgen receptors in hair follicles, causing them to shrink and eventually stop producing hair.
This process is known as follicular miniaturization, and it is the hallmark of AGA[4][2][1].
What is the Role of DHT in Androgenetic Alopecia?
DHT is a hormone that is produced when the 5-alpha reductase enzyme converts testosterone.
DHT is the primary cause of AGA, as it binds to androgen receptors in hair follicles, causing them to shrink and eventually stop producing hair.
This process is known as follicular miniaturization, and it is the hallmark of AGA[2][3][4].
The relationship between testosterone and hair loss is complicated.
Having high levels of testosterone does not necessarily cause hair loss. The sensitivity of your hair follicles determines hair loss, which is determined by genetics.
The AR gene makes the receptor on hair follicles that interact with testosterone and DHT.
If the AR gene is more sensitive to DHT, then hair loss is more likely to occur[3].
The Genetics of AGA
While DHT is the primary cause of AGA, genetics also play a significant role in the development of this condition.
AGA is an inherited trait, and it is more common in people with a family history of the condition.
Researchers have identified several genes that are associated with AGA, including the androgen receptor gene, which regulates the body’s response to androgens like testosterone and DHT[2][1].
Symptoms of Androgenetic Alopecia
The main symptom of AGA is losing more hair than usual, but this can be harder to identify than you might think. The following symptoms can provide some clues:
– Widening part: If you part your hair, you might start to notice your part getting wider, which can be a sign of thinning hair.
– Receding hairline: If your hairline looks higher than usual, it may be a sign of thinning hair.
– Thinning hair: Hair loss related to AGA tends to happen gradually. While some people might experience hair loss as early as puberty, others might not notice symptoms until their middle ages.
– Bald spots: In some cases, AGA can lead to the formation of bald spots on the scalp.
– Thinning all over the scalp: Female pattern baldness often results in thinning all over the scalp and might look like widening or thinning around the part. It typically occurs after age 65 but, for some females, it can begin early in their lives[2][5].
AGA differs from other types of hair loss in several ways.
For example, AGA is a hereditary condition, while other types of hair loss may be caused by a variety of factors, such as stress, medication, or disease.
AGA typically affects the top and front of the scalp, while other types of hair loss may occur in different areas of the body.
AGA is caused by the miniaturization of hair follicles, which results in thinner, shorter, and less pigmented hair.
Other types of hair loss may result in complete hair loss or the formation of bald patches[4][3][1][2][6].
What are the Treatment Options for Androgenetic Alopecia?
There are several treatment options for AGA, including:
- Medications: Two medications, finasteride and minoxidil, are FDA-approved for the treatment of AGA. Finasteride works by blocking the conversion of testosterone to DHT, while minoxidil works by increasing blood flow to hair follicles
[4][6].
- Laser therapy: Low-level laser therapy (LLLT) has been shown to be effective in promoting hair growth in people with AGA. LLLT works by stimulating hair follicles and increasing blood flow to the scalp
[2].
- Scalp micro needling: Scalp micro needling involves using a device with tiny needles to create small punctures in the scalp. This process is thought to stimulate hair growth by increasing blood flow to the scalp and promoting the production of growth factors [2].
- Hair mesotherapy: Hair mesotherapy involves injecting a mixture of vitamins, minerals, and other nutrients into the scalp. This process is thought to promote hair growth by providing the hair follicles with the nutrients they need to grow [2].
- Hair transplantation: Hair transplantation involves taking hair follicles from one part of the scalp and transplanting them to another part of the scalp. This process is typically used to treat bald spots on the scalp [2].
Conclusion
In conclusion, testosterone and DHT play a crucial role in the development of androgenetic alopecia.
While genetics also play a significant role in the development of this condition, the link between testosterone and hair loss is well-established.
However, it is essential to note that testosterone replacement therapy is not a significant risk factor for prostate cancer.
If you are experiencing hair loss, speaking with a healthcare professional to determine the underlying cause and develop an appropriate treatment plan is essential.
FAQs
Is testosterone linked to hair loss in men?
Yes, testosterone is indeed linked to hair loss in men.
Androgenetic alopecia, commonly known as male pattern baldness, is men’s most prevalent form of hair loss.
It occurs due to the combination of genetic factors and the influence of male sex hormones, including testosterone.
Testosterone is converted into dihydrotestosterone (DHT) by the enzyme 5-alpha reductase.
DHT affects hair follicles by miniaturizing them, leading to the gradual thinning of hair and eventual hair loss.
Does high testosterone levels cause hair loss in women?
Hair loss in women is typically associated with hormonal imbalances, and high testosterone levels can contribute to this condition.
However, it’s important to note that female pattern hair loss differs from male pattern baldness.
While testosterone plays a role, other factors such as genetics, age, and underlying health conditions also contribute to hair loss in women.
Elevated testosterone levels can disrupt the hair growth cycle, leading to thinning hair or excessive shedding.
Can low testosterone cause hair loss?
While low testosterone levels are not the primary cause of hair loss in men, they can still play a role.
Low testosterone levels may result in an imbalance of hormones, leading to hair thinning or shedding.
However, it’s essential to consult with a healthcare professional to determine the underlying cause of hair loss, as various factors can contribute to the condition.
Are there treatments available to address testosterone-related hair loss?
Yes, several treatment options are available to address testosterone-related hair loss.
Medications such as finasteride and minoxidil are commonly prescribed to slow down hair loss and promote hair regrowth.
Finasteride inhibits the conversion of testosterone into DHT, while minoxidil stimulates hair follicles to increase hair growth.
Hair transplant surgery is another option for individuals seeking a more permanent solution to restore their hair.
Can testosterone replacement therapy (TRT) cause hair loss?
Testosterone replacement therapy (TRT) may have varying effects on hair loss.
In some cases, TRT can exacerbate hair loss, particularly in individuals who are genetically predisposed to male pattern baldness.
The increased testosterone levels can lead to an increase in DHT, affecting hair follicles.
However, the impact of TRT on hair loss varies from person to person, and not everyone experiences significant hair loss as a result of testosterone therapy.
It’s essential to discuss the potential risks and benefits of TRT with a healthcare professional before starting any hormonal treatment.
Resources:
- https://onlinelibrary.wiley.com/doi/full/10.1111/exd.14130
- https://www.healthline.com/health/hair-loss-and-testosterone
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4174066/
- https://medlineplus.gov/genetics/condition/androgenetic-alopecia/
- https://www.science.gov/topicpages/h/hair+loss+alopecia
- https://academic.oup.com/jcem/article/104/7/2875/5342938
- https://www.ncbi.nlm.nih.gov/books/NBK430924/
- https://www.health.harvard.edu/mens-health/testosterone-therapy-prostate-cancer-and-cardiovascular-risk
