DOSEGUY

Topilutamide

guinea pig

Also seen as: Fluridil

The Dose Guy’s verdict
Sep 1, 2026
1 source

Topilutamide has a completed, published, placebo-controlled trial, which is more than most topical antiandrogens can claim. One trial, 43 men, from 2002. It showed anagen ratios climbing and no detectable drug in serum at the three draws they checked, which is exactly what you want from a topical antiandrogen. The problem is that the data is small, old, and nobody has replicated it in 24 years. Niche and unproven, but not unreasonable if you can source it.

Would I take it?Caution, thin and dated.

What it is

A topical androgen receptor blocker available in a few European markets and as raw compound elsewhere. The design is clever: the molecule is hydrophobic and breaks down on contact with water, so it stays in the oily environment of the scalp and degrades before reaching your bloodstream. That is exactly the property every topical antiandrogen is chasing, and topilutamide had the published human data to show it works. The one small trial from 2002 confirmed the principle: applied at 2%, anagen ratios went up, and neither the drug nor its breakdown product showed up in serum.

What the research shows

One trial, one paper, two decades old:

In 43 men with androgenetic alopecia, topilutamide 2% raised mean anagen hair percentage from 76% to 85% at three months and to 87% at nine months. Placebo showed no change at three months.Dermatol Surg 2002 · RCT · n=43
Crossover participants replicated the response: anagen percentage rose from 76% to 85% after six months of treatment.Dermatol Surg 2002 · RCT · n=43
Neither topilutamide nor its decomposition product was detectable in serum at day 0, day 3, or day 90. Sexual function, libido, and laboratory values remained normal throughout.Dermatol Surg 2002 · RCT · n=43
No follow-up trial or independent replication of the 2002 study has been published.as of Aug 2026

Realistic protocols

Topilutamide is available as Eucapil in a few European countries, a pre-made 2% solution in isopropyl myristate. Outside Europe, sourcing means finding the raw compound and mixing it yourself, which puts it in research chemical territory despite being technically approved somewhere.

Apply once daily to dry scalp. The compound breaks down in water, so applying to wet hair or mixing into a water-based vehicle defeats the purpose. Let it absorb. Like every topical antiandrogen, this is maintenance: the effect reverses when you stop. The trial used 2%, and no data suggests a different concentration performs better.

Concentration2%The trial concentration and the Eucapil formulation.
FrequencyOnce dailyApplied to dry scalp. Breaks down in water, so wet hair defeats it.
DurationOngoingMaintenance, not a course. Effects reverse on discontinuation.

Side effects

The one published trial reported a clean side-effect profile, but it was small and short:

anecdotalMild scalp irritation from the vehicle, reported in community use. A separate 21-day forearm patch study testing up to 6% found no sensitization or irritation.
anecdotalOiliness or greasiness at the application site, from the isopropyl myristate vehicle.
unknownOne trial, 43 men, over 20 years ago. Short-term safety looked clean, but long-term use and independent replication remain unstudied.

Where to buy

RUO.bio–
$28 / 600mg vial$0.047/mg
✓ verified Sep 12
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