Hair Health . Symptoms guide
Finasteride Not Working: What to Check Next
Quick answer
Finasteride works for most men but not all. While the medication reliably lowers circulating DHT, serum blood tests cannot measure local follicle sensitivity, so the useful next steps are reviewing the broader androgen profile, ruling out nutritional and thyroid deficits that mask treatment response, and considering whether an adjunct therapy or specialist review is appropriate. A combined panel covers the bloodwork that would otherwise require several separate tests.
This patient information is being clinically reviewed by our team. The factual content draws on UK guidance (NHS, NICE, British Association of Dermatologists, and other specialist society guidance where cited).
What this might be
- Inadequate DHT suppression. While finasteride reliably lowers circulating DHT, serum blood tests cannot measure local follicle sensitivity. Checking your broader androgen profile helps ensure there are no unaddressed systemic hormonal surges overriding your treatment. Options include switching to a different 5-alpha-reductase inhibitor (dutasteride), adding a synergistic pathway with topical minoxidil (licensed for androgenetic alopecia at 2 and 5 percent; oral minoxidil is off-licence and prescribed by clinician decision), or checking for non-androgenetic factors.
- Coexisting telogen effluvium. Iron or thyroid deficits can drive ongoing shedding even when finasteride is working on miniaturisation.
- Vitamin D deficiency. Independently causes telogen effluvium by disrupting normal follicle cycling, which can mask the success of finasteride, but it does not affect the drug response itself.
- Receptor sensitivity factors. Genetic variation in androgen receptor response. Bloodwork rules out the reversible causes first.
Common features that suggest this
- Twelve or more months on finasteride
- Hair loss continuing or worsening
- No improvement in shed volume
- Other potential drivers (stress, illness, restrictive diet)
Recommended tests
Same-day appointments at our Harley Street clinic, results clinician-reviewed.
Need a marker not in these panels? Build a custom panel and a GMC-registered clinician will design one for you.
Markers your clinician will commonly look at
These are the individual blood markers in the recommended panels above. Click any to read what it measures, its UK reference range, and what high or low values mean.
Testing advice
Morning appointment recommended. Continue finasteride at your usual dose unless your prescriber has told you otherwise; testing on treatment is what we are interested in.
Common questions
Will testing DHT tell me if finasteride is working?
A serum blood test can verify that the medication is actively lowering your systemic DHT levels, but it cannot measure what is happening inside your scalp. Because hair loss is driven by follicle sensitivity to the remaining DHT, a normal or suppressed blood reading will not guarantee hair preservation.
Should I switch to dutasteride?
Switching to dutasteride is a clinical decision driven almost entirely by clinical progression rather than bloodwork alone. Our clinicians can review your systemic health markers to ensure no underlying nutritional or metabolic issues are blocking your progress, before discussing specialised treatment variations.
Related symptoms
Sources and further reading
This page provides general information only and is not a substitute for medical advice. A GMC-registered clinician will review your results and tailor any recommendations to you personally.