Seeing your hair thin can be stressful, and it’s normal to want answers. One hormone often linked to male hair loss is dihydrotestosterone or DHT. You might have heard of it before, especially if you’ve looked into “DHT blockers” or treatments like Finasteride.
But what exactly is DHT, and why does it cause hair to fall out for some men? Let’s break it down.
What is DHT?
DHT stands for dihydrotestosterone, a powerful male sex hormone made naturally in the body.
It’s formed when testosterone is converted by an enzyme called 5-alpha reductase, a process that mainly takes place in the testes and prostate in men (1). Everyone has this process happening all the time, and roughly 10% of testosterone is converted into DHT each day (2).
DHT has several essential roles in male development. But, like all hormones, balance matters. When levels become too high, it can start to cause unwanted changes on the scalp.
What does DHT do in the body?
DHT plays a key role in male development, especially during puberty. It helps produce many of the physical characteristics typically associated with masculinity, such as a deeper voice, facial and body hair growth, and the development of the genitals and prostate.
Throughout adulthood, DHT continues to play useful roles: maintaining muscle mass, supporting libido, and contributing to normal male physiology. In other words, all men need a healthy level of DHT in the body throughout life for normal, healthy male sexual development.
However, it has different effects in different parts of the body. While DHT encourages hair growth on areas like the face and chest, high levels of DHT can have the opposite effect on the scalp (1).
How DHT affects scalp hair
Not everyone with high DHT levels will experience hair loss. But in men who are genetically predisposed to androgenetic alopecia (male pattern baldness), hair loss starts at the follicles.
Inside the hair follicles on the scalp are proteins known as androgen receptors that DHT can bind to. When bound, the follicles gradually start to shrink through a process called miniaturisation. This has a direct impact on the hair growth cycle.
Here’s a closer look at how this works:
DHT binds to receptors inside scalp hair follicles.
The follicles produce finer, shorter hairs with each growth cycle.
Eventually, the follicles stop producing visible hair altogether.
The result is gradual thinning, usually starting at the temples or crown.
This process happens slowly, often over several years. That’s why early hair loss can seem subtle at first before becoming more noticeable over time.
Why are some people more sensitive to DHT?
The difference mainly comes down to genetics: some people are simply more sensitive to DHT than others. If your follicles are more sensitive, you’re more likely to experience hair loss. Meanwhile, men with less sensitivity can have high DHT levels and manage to keep a full head of hair.
Many genes are involved, but the key genetic factor involves variations in the genes that code for androgen receptors, the proteins that DHT binds to. These variations (which can be inherited from either side of your family) determine how readily DHT interacts with your follicles.
Genetics aren’t the only factor, though. Lifestyle and overall health can also influence how quickly or severely hair loss progresses. Stress, poor diet, smoking, and lack of sleep can all affect hormone balance and circulation, which may worsen the effects of DHT on the scalp.
Taking care of your general health can’t change your genes, but it can help slow the process and support healthier hair growth overall.
Can you reduce DHT or block its effects?
Yes, and that’s the basis of several proven hair loss treatments. This includes the DHT blocker Finasteride, one of the most common treatments for male pattern baldness.
Finasteride works by inhibiting the 5-alpha reductase enzyme (the one that turns testosterone into DHT) (3). Doing so reduces the levels of DHT in the body, lowering the amount that reaches the hair follicles. This helps to slow hair loss or even encourage regrowth in some men.
Other treatments, like Minoxidil, work differently. Minoxidil doesn’t affect DHT levels but instead helps improve blood flow to the hair follicles and extends the growth phase of the hair cycle. Many people find that using both together offers the best results.
Managing hair loss safely
While hair loss can feel frustrating and disheartening, understanding what’s happening is the first step towards managing it. And the good news: If DHT is contributing to your hair thinning, there are clinically proven treatments that may help slow the process and preserve what you have.
At Oxford Online Pharmacy, our UK-registered clinicians can guide you through safe treatment options designed around your needs, including both DHT-blocking and non-hormonal approaches.
References
NHS. Dihydrotestosterone - South Tees Hospitals NHS Foundation Trust [Internet]. South Tees Hospitals NHS Foundation Trust. 2022.
You and Your Hormones from the Society for Endocrinology. Dihydrotestosterone [Internet]. Yourhormones.info. 2018.
NHS. Common questions about Finasteride [Internet]. nhs.uk. 2023.