DHT and Hair Loss: What It Does to Hair Follicles

What DHT is

Dihydrotestosterone, usually shortened to DHT, is made when the enzyme 5-alpha-reductase converts testosterone. DHT has normal roles in the body. The issue in androgenetic alopecia is not simply “too much DHT”: genetically susceptible follicles in particular scalp areas respond to androgen signalling differently.

Over repeated hair cycles, affected follicles can spend less time in the growth phase and produce progressively finer, shorter hairs. This is follicle miniaturisation. A clinical review describes DHT-driven cycle changes continuing until some hairs no longer emerge visibly from the scalp. Read the review on PubMed →

Why the pattern matters

In men, androgenetic hair loss often appears at the temples, hairline and crown. In women, it more often appears as reduced density through the central scalp or a widening part. Neither pattern proves the cause by itself. Sudden shedding, smooth patches, scalp pain, inflammation, scarring or loss elsewhere on the body deserves clinical assessment.

Read the broader guide to androgenetic alopecia →

Where 650nm low-level laser therapy fits

Low-level laser therapy and DHT-directed medicines are different mechanisms. LLLT research asks whether light exposure can support activity in follicles that are still functioning; it does not reduce DHT production or block androgen receptors.

A meta-analysis of 11 sham-controlled randomised trials reported an increase in hair density in adults with androgenetic alopecia, while also noting meaningful differences between the included studies. Review the meta-analysis →

That evidence is why a light-based device belongs in a conversation about pattern hair loss, not every condition that causes shedding. It is also why timing matters: supporting a miniaturising but functioning follicle is a different proposition from restoring one that no longer functions.

What LLLT does not do

• It does not lower DHT.
• It does not establish why your hair is changing.
• It does not replace evaluation for hormonal, nutritional, autoimmune, medication-related or scarring causes.
• It cannot promise a particular change for an individual.

If you are considering medicine that changes androgen signalling, speak with a qualified clinician about suitability, risks and monitoring. Do not start or stop a medicine based on a product page.

A useful next step

If thinning is gradual and follows a familiar crown, part or hairline pattern, document it in consistent lighting and ask a clinician whether the pattern is consistent with androgenetic alopecia. If the change is sudden, patchy, painful or accompanied by other symptoms, start with clinical assessment rather than a device.

Compare laser caps with finasteride and minoxidil → · See the evidence and its limits →

Not intended to diagnose, treat, cure, or prevent any disease. The clinical studies referenced evaluated low-level laser therapy as a category and do not represent clinical testing of this specific product. Individual results vary and depend on consistent use over time. The FDA 510(k) clearance (K261253) is held by the manufacturer.