on October 01, 2025
Hair loss is a common concern affecting millions of people worldwide. While many factors can contribute to thinning hair, one of the primary culprits behind the most prevalent form of hair loss is a powerful hormone known as Dihydrotestosterone, or DHT. Understanding DHT is the first step toward effectively managing and addressing pattern hair loss.
This article delves into the science behind DHT, explaining how it triggers hair loss, the role of genetics, and the distinct ways it affects men and women.
How DHT Causes Hair Follicle Miniaturization
Androgenetic alopecia (AGA), more commonly known as male or female pattern baldness, is driven by a combination of genetics and hormones, with DHT taking centre stage. In individuals who are genetically predisposed, certain hair follicles on the scalp, particularly at the temples and crown, have a heightened sensitivity to DHT.
The process begins when an enzyme called 5α-reductase converts testosterone into DHT. This DHT then binds to androgen receptors located in the hair follicles. This binding action sets off a chain reaction that disrupts the natural hair growth cycle. It upregulates inhibitory factors that suppress the growth of crucial cells within the follicle.
This leads to the defining characteristic of pattern baldness: miniaturization. Over successive growth cycles, the affected hair follicles progressively shrink. The active growth phase (anagen) becomes shorter, while the resting phase (telogen) gets longer. As a result, the hairs produced become thinner, shorter, and lighter in colour. Strong, healthy terminal hairs are gradually replaced by wispy, non-pigmented vellus hairs, and in advanced stages, the follicles may stop producing hair altogether.
It's in Your Genes: Predisposition and DHT Sensitivity
You might wonder why some people with high testosterone levels keep a full head of hair while others experience significant loss. The answer lies in genetics. It is not the amount of DHT in your bloodstream that matters most, but rather how sensitive your hair follicles are to it.
A strong family history is a major indicator of potential hair loss; studies show that around 80% of men experiencing baldness have a father who is also bald. This genetic predisposition is largely linked to variations in the androgen receptor (AR) gene, which can make scalp follicles overly responsive to DHT's miniaturizing effects. For these individuals, even normal physiological levels of DHT can trigger the hair loss process. This genetic sensitivity is the key reason why androgenetic alopecia runs in families.
The Androgen Paradox: Why DHT Affects Scalp and Body Hair Differently
One of the most fascinating aspects of DHT is its paradoxical effect on different parts of the body. While it is a primary driver of scalp hair loss, it is the very same hormone that stimulates the growth of beard, chest, armpit, and pubic hair. This phenomenon is known as the "androgen paradox".
The reason for this dual action is that hair follicles in different anatomical locations are programmed to respond to DHT in different ways. Facial hair follicles, for example, are stimulated by DHT, leading to robust growth. In contrast, scalp hair follicles in genetically susceptible individuals react negatively, leading to miniaturization. This highlights that a hormone's effect is determined by the specific receptor and cellular response within a given tissue.
Different Patterns: How Hair Loss Presents in Men and Women
Although DHT is the common link, androgenetic alopecia manifests differently between the sexes due to varying hormonal environments.
- Male Pattern Baldness: This is the classic pattern of hair loss in men, often starting with a receding hairline at the temples and thinning at the crown (the vertex). This progression is so common that it is often tracked using the Norwood-Hamilton Classification scale and can begin as early as a man's late teens or early twenties.
- Female Pattern Hair Loss (FPHL): In women, DHT-related hair loss typically involves a diffuse thinning of hair over the entire crown area, while the frontal hairline usually remains intact. FPHL tends to begin later in life, often becoming more noticeable after menopause when protective estrogen levels decline. In some cases, it can also be a sign of an underlying hormonal imbalance, such as Polycystic Ovary Syndrome (PCOS).
Taking Control: Supporting Your Scalp Health
Understanding the role of DHT is crucial for addressing hair loss. While medical treatments focus on inhibiting DHT production, supporting the health of your scalp and follicles is an essential part of any comprehensive hair care routine. Creating an optimal environment for hair to grow is paramount.
For those looking to proactively care for their scalp, specialised products can make a significant difference. BioScalp products, such as its DHT-inhibiting shampoo, are expertly formulated to nourish the scalp and support hair follicle vitality. By focusing on creating a healthy foundation, products like these can complement other treatments and help you manage the challenges of DHT-related hair thinning.
Ultimately, while DHT and genetics play a powerful role in pattern hair loss, knowledge is power. By understanding the underlying causes, you can explore targeted solutions and adopt a scalp care regimen that gives your hair the best possible support.
