- Finasteride: oral type II 5-alpha-reductase inhibitor, licensed for male androgenetic alopecia at 1 mg since 1997 (US) and 1998 (UK).
- Pyrilutamide (KX-826): topical nonsteroidal androgen receptor antagonist developed by Kintor Pharmaceutical, not approved anywhere.
- Finasteride evidence: multiple randomised controlled trials, long-term extensions and systematic reviews in peer-reviewed journals.
- Pyrilutamide evidence: company-reported Phase 2 trials in China and the US, plus a positive China Phase 3 reported in March 2026 (666 men, 10.65 hairs/cm² placebo-adjusted at 24 weeks).
- No head-to-head trial exists between the two.
- Pyrilutamide from any supplier, including Norwood Labs, is a research chemical, not a medicine.
- Finasteride lowers DHT across the whole body by blocking the enzyme that makes it. Pyrilutamide blocks the receptor DHT binds to, locally, in the skin where it is placed.
- Finasteride is a licensed prescription medicine with a mature, peer-reviewed evidence base. Pyrilutamide is an investigational compound whose data is company-reported and not yet published in full.
- They are different categories of thing, not two options on one shelf. Comparing them is useful for understanding mechanism, not for choosing a product.
What is the core difference in mechanism?
Finasteride reduces the supply of DHT; pyrilutamide blocks the receptor that DHT acts on. Finasteride inhibits type II 5-alpha-reductase, the enzyme that converts testosterone to dihydrotestosterone, and because it is taken orally, serum and scalp DHT both fall. In the original registration trials, 1 mg daily lowered scalp DHT by around 64% and serum DHT by around 68% [1]. Pyrilutamide takes a different route. It is a nonsteroidal androgen receptor antagonist, structurally related to the same chemical lineage as RU-58841, and it competes with DHT and testosterone for the androgen receptor itself. The amount of DHT in circulation is not changed; what changes is whether the hormone can signal in the tissue where the compound is present. We cover the molecule in more depth in What is pyrilutamide?
Why does systemic versus local matter?
Because it decides where the effect, and any unwanted effect, can occur. Oral finasteride acts everywhere the enzyme is expressed, which is the reason its trial literature includes sexual adverse events at low rates above placebo, alongside reduced ejaculate volume and changes in serum PSA [2]. A topical androgen receptor antagonist is designed around a different idea: occupy receptors in the skin, then be cleared quickly so that very little reaches the rest of the body. Whether that design works in practice is an empirical question answered only by pharmacokinetic and safety data, and for pyrilutamide the public data on that point is limited to what Kintor has disclosed in press releases. The same logic, and the same caveat, apply to RU-58841, which we discuss in RU-58841 vs finasteride.
How do the evidence bases compare?
They are not comparable in size, duration or independence. Finasteride's 1 mg programme in men with androgenetic alopecia enrolled 1,553 men across two one-year placebo-controlled trials, with hair counts, photographs and patient assessment as endpoints, and the results were published in a peer-reviewed journal in 1998 [1]. A 2010 systematic review in Archives of Dermatology pooled twelve randomised trials and concluded that daily finasteride produced measurable hair-count and assessment gains over placebo in men, with the trade-off of a higher rate of sexual adverse events [2]. That is a mature literature with independent re-analysis and critique, including a 2015 meta-analysis that questioned how well the trials captured adverse events [3].
Pyrilutamide's evidence is newer and thinner. Kintor has reported a positive China Phase 2 in men (2021), a positive China Phase 2 in women (2022), a US Phase 2 that gave a change from baseline but no placebo-adjusted significance (2023), a 52-week open-label safety study (2025), and the pivotal China Phase 3 stage in March 2026: 666 men, a placebo-adjusted gain of 10.65 hairs/cm² at 24 weeks on the 1.0% tincture, p below 0.0001, with no drug-related serious adverse events [4]. Every one of those results exists as a press release or exchange filing. None has yet appeared as a full peer-reviewed paper. The full timeline, with the numbers as the company stated them, is in Pyrilutamide clinical trials.
Can the hair-count numbers be set side by side?
Only loosely, and not as a ranking. Hair counts depend on the scalp area measured, the counting method, the baseline severity of the men enrolled, and the trial length. A placebo-adjusted gain of about 10 hairs/cm² at 24 weeks for pyrilutamide and the various finasteride figures reported at 48 weeks or longer come from different populations under different protocols. Network meta-analyses that try to put licensed agents on one scale still carry wide uncertainty and do not include pyrilutamide at all. The honest statement is that pyrilutamide's Phase 3 effect size sits in the general range where approved agents operate, and that nothing more precise can be said until a head-to-head trial is run.
What about safety and side effects?
The reported profiles differ in kind, but so does the quality of the reporting. For finasteride, the adverse events are well characterised: a small excess of sexual dysfunction over placebo in the trials, a lowering of serum PSA that matters for prostate screening, and a contraindication in pregnancy because of effects on male fetal development [1][2]. For pyrilutamide, Kintor consistently reports mild local effects such as scalp irritation at rates similar to vehicle, and no drug-related sexual dysfunction, including across the 52-week open-label study [4]. That is the result a topical antagonist is meant to produce, but the dataset is a few hundred people over at most a year, reported by the sponsor, and not independently reviewed. We go through the detail in Pyrilutamide side effects.
What is the legal and regulatory status of each?
Finasteride is a prescription-only medicine in the UK and the EU, with a marketing authorisation and a product licence behind it. Pyrilutamide has no marketing authorisation anywhere. Kintor has said it intends to file a new drug application in China following the Phase 3 result; until a regulator acts on that, the compound remains investigational, and outside a clinical trial it is available only as a reference material for laboratory research. That is the basis on which Norwood Labs Ltd supplies it. Our pyrilutamide powder and solution are not Kintor's tincture, are not sold for human use, and are accompanied by a published sample report from a third-party analytical laboratory that documents identity and assay for the named sample, not safety or performance in people.
So which one is "better"?
The question does not have an answer, because the two have never been compared and are not the same kind of product. Finasteride is a licensed medicine whose benefits and risks are documented well enough for a prescriber to weigh them. Pyrilutamide is a research compound whose most important trial result is seven months old and unpublished. What can be said is that they act at different points in the same pathway, that pyrilutamide's design aims at local rather than systemic action, and that the data supporting it is promising, company reported, and incomplete. Anyone considering a medicine should speak to a prescriber; anyone studying the molecule should read the primary sources below.
References
- Kaufman KD, Olsen EA, Whiting D, et al. Finasteride in the treatment of men with androgenetic alopecia. Finasteride Male Pattern Hair Loss Study Group. J Am Acad Dermatol. 1998;39(4 Pt 1):578-589. PMID 9777765
- Mella JM, Perret MC, Manzotti M, Catalano HN, Guyatt G. Efficacy and safety of finasteride therapy for androgenetic alopecia: a systematic review. Arch Dermatol. 2010;146(10):1141-1150. PMID 20956649
- Belknap SM, Aslam I, Kiguradze T, et al. Adverse event reporting in clinical trials of finasteride for androgenic alopecia: a meta-analysis. JAMA Dermatol. 2015;151(6):600-606. PMID 25830296
- Kintor Pharmaceutical. Phase III KX-826 tincture 1.0% for AGA reached primary endpoint. Press release, 18 March 2026. kintor.com.cn