DHT and hair loss: what dihydrotestosterone is and why it matters

Medisch diagram van DHT dat zich bindt aan de androgeenreceptor in een haarfollikel, gerelateerd aan androgenetische haaruitval.

Understanding the hormone linked to androgen-sensitive pattern hair thinning

Dihydrotestosterone (DHT) is a potent androgen hormone formed from testosterone through the action of the enzyme 5-alpha-reductase. This biochemical conversion is clinically significant because DHT plays a central role in androgen-sensitive hair loss patterns such as alopecia androgenetica.

Because DHT binds strongly to androgen receptors within genetically susceptible scalp hair follicles, it can influence follicular behavior over time.

For a full overview of the condition itself, see:

Read our guide on alopecia androgenetica

What is DHT?

DHT (dihydrotestosterone) is an androgen derived from testosterone. Although testosterone circulates throughout the body, its conversion into DHT increases androgen potency in tissues that are sensitive to hormonal signaling.

DHT is naturally present in both men and women. Its biological effects depend not only on circulating hormone levels but also on local tissue sensitivity and receptor activity.

In the context of hair, DHT becomes relevant when follicles are genetically predisposed to respond more strongly to androgen stimulation.

How DHT is produced from testosterone

DHT is formed when testosterone is converted by the enzyme 5-alpha-reductase.

The simplified pathway:

  • Testosterone
  • 5-alpha-reductase (enzyme conversion step)
  • Dihydrotestosterone (DHT)

For a deeper explanation of this enzymatic conversion, see:

→ 5-alpha-reductase and hair loss

Understanding this pathway clarifies why some medical and research strategies focus on influencing the DHT cascade.

How DHT affects hair follicles

Hair growth follows a cyclical process consisting of:

  • Anagen (growth phase)
  • Catagen (transition phase)
  • Telogen (resting phase)

In androgen-sensitive follicles, DHT is associated with a gradual process known as miniaturization.

Miniaturization involves:

  • Shortening of the anagen phase
  • Progressive reduction in follicle size
  • Production of thinner hair shafts
  • Gradual decrease in visible density

Miniaturization refers to the gradual reduction in follicle diameter over successive growth cycles, resulting in finer and shorter hair fibers.

Over successive cycles, terminal hairs may become finer and shorter.

This mechanism is characteristic of alopecia androgenetica.

DHT and alopecia androgenetica

Alopecia androgenetica results from the interaction between genetic predisposition and androgen sensitivity. DHT is central to this interaction in susceptible hair follicles.

DHT does not cause hair loss in all individuals. The response depends on how susceptible a person’s hair follicles are to androgen signaling.

Typical clinical patterns include:

In men

  • Receding temples
  • Thinning at the crown
  • Progressive pattern over years

In women

  • Widening of the central part
  • Diffuse thinning over the crown
  • Preservation of the frontal hairline in many cases

Other forms of hair loss, such as telogen effluvium or inflammatory conditions, follow different mechanisms and are not primarily driven by DHT.

Why some strategies focus on the DHT pathway

Because DHT influences androgen-sensitive follicular changes, certain medical and research strategies focus on influencing this hormonal pathway.

Medical context

Some prescription treatments are designed to reduce DHT formation by inhibiting 5-alpha-reductase. These are regulated therapies and require professional evaluation.

Botanical research

Certain plant-derived compounds are investigated for their potential interaction with androgen pathways, including DHT-related mechanisms.

One example frequently discussed in this context is:

→ Saw Palmetto and the DHT Pathway

Botanical extracts do not function identically to prescription medications.

Is DHT always the cause of hair loss?

No.

While DHT is central in androgenetic alopecia, other forms of hair thinning may result from:

  • Acute or chronic stress (telogen effluvium)
  • Nutritional deficiencies
  • Autoimmune processes
  • Inflammatory scalp disorders
  • Hormonal changes unrelated to androgen sensitivity

In these cases, DHT-targeted approaches may not address the primary cause.

Correctly identifying the underlying hair loss pattern is essential before focusing on DHT-related mechanisms.

When to consider the DHT mechanism

The DHT pathway is most relevant when hair thinning:

  • Develops gradually over years
  • Follows a recognizable distribution pattern
  • Occurs with a family history of similar thinning
  • Affects temples, crown, or central part

Sudden shedding, patchy hair loss, or scalp symptoms should be evaluated medically.

Summary

DHT (dihydrotestosterone) is a potent androgen formed from testosterone via 5-alpha-reductase. In genetically susceptible hair follicles, DHT is associated with progressive miniaturization and pattern hair thinning characteristic of alopecia androgenetica.

Understanding the DHT pathway helps clarify why certain medical and research strategies focus on androgen-sensitive mechanisms.

To explore the full biological framework, read:

Frequently asked questions about DHT and hair loss

What does DHT do to hair follicles?

In genetically susceptible hair follicles, DHT is associated with miniaturization: the anagen (growth) phase becomes shorter and follicles gradually produce thinner hair fibers, which can reduce visible density over time.

Is DHT always the cause of hair loss?

No. DHT is central in androgenetic alopecia, but other forms of hair loss can have different causes such as telogen effluvium, deficiencies, autoimmune processes, or inflammatory conditions. In those cases, the DHT mechanism is not the primary explanation.

Can DHT-related thinning also occur in women?

Yes. While hormonal dynamics differ by sex, androgen-sensitive pattern thinning can also occur in women. DHT-related follicular sensitivity may play a role in some cases of female pattern hair thinning.