DHT gets discussed constantly in men's health content, but most of it either goes too deep into biochemistry or stays too shallow to say anything useful. This sits in the middle: what DHT is, what it does to hair follicles, and why its impact is faster and more visible on fine hair than any other type.
What DHT Is
Dihydrotestosterone is a hormone your body produces from testosterone. The conversion happens through an enzyme called 5-alpha reductase, which is concentrated in scalp tissue. That is a key part of why DHT affects hair specifically.
DHT binds to androgen receptors with roughly three to five times the potency of testosterone. It attaches harder and releases more slowly. In scalp follicles, this starts a process that progressively changes the hair produced.
What DHT Does at the Follicle
At the base of each hair follicle sits the dermal papilla, a cluster of specialised cells that controls hair production. When DHT repeatedly occupies the androgen receptors in the papilla across multiple growth cycles, it sends a miniaturisation signal. The papilla shrinks. The shaft it produces gets finer and shorter with each successive cycle.
The hair does not shed in clumps. It sheds normally at the end of each cycle. But the replacement shaft comes back a fraction finer. Run this across five, ten, fifteen years and a full terminal hair becomes a barely-visible vellus hair. It did not disappear overnight. It faded, cycle by cycle.
The Numbers That Make This Clear
Two men, same rate of miniaturisation. Man A starts at 100 micrometres shaft diameter. Man B starts at 50 micrometres. Both lose 30 micrometres per follicle over several years.
Man A is at 70 micrometres. He looks the same. Nobody has noticed anything.
Man B is at 20 micrometres. His scalp is visible under bathroom lighting. His part line has widened.
Identical biology. Identical timeframe. Completely different result. Fine hair has less distance between its starting point and the threshold where it becomes cosmetically invisible.
The Geometry Problem
Fine straight hair lies flat against the scalp with no natural curl or expansion. When individual shafts become finer, the scalp shows through directly. Nothing compensates.
Wavy or curly hair expands away from the scalp. Even as strands miniaturise, the overall structure still reads as full for much longer. Fine straight hair has no equivalent buffer. The moment density drops, the scalp is visible.
Why Reducing DHT Everywhere Is Not Always the Answer
The standard approach is finasteride, which blocks 5-alpha reductase and reduces DHT throughout the body. It works at the scalp. It also reduces DHT everywhere else, including in tissues responsible for libido, mood, body composition, and neurological function.
For men on testosterone replacement therapy or hormonal protocols, this trade-off is often incompatible with their primary goals.
The alternative is a topical androgen receptor antagonist applied directly to the scalp, occupying androgen receptors in scalp follicle tissue locally without changing systemic DHT levels. EVARON Hair Serum contains PSK-3841, a non-steroidal compound in this category, applied once daily to the scalp.
The One Upside of Fine Hair
Fine hair is more sensitive to follicle changes on the way down. It is also more visually responsive to improvement on the way up. A modest increase in average shaft diameter across a large proportion of follicles produces a clearly visible change for fine-haired people, because the threshold is so close to begin with.
Starting a daily scalp care routine early, before thinning becomes advanced, produces better outcomes than starting late. The biology of hair growth cycles means any follicle-level change takes months to appear at the surface. Early action gives the most to work with.
