Peptide & Experimental
Pyrilutamide (KX-826)
Androgen receptor antagonist for use on the skin, not approved · Pyrilutamide, KX-826
Pyrilutamide, development name KX-826, is a topical solution against hereditary hair loss from the Chinese manufacturer Kintor. It blocks the androgen receptor directly at the scalp instead of lowering hormone levels like finasteride. After a failure in 2023, a second large phase 3 trial reported a clear lead over placebo in 2026. So far, the figures are known only from stock exchange announcements.
What pyrilutamide is
Pyrilutamide is a synthetic androgen receptor antagonist that Kintor Pharmaceutical of Suzhou is developing as a solution for application to the scalp. It is being tested against hereditary hair loss in men and women and against acne. It is not approved anywhere; Kintor intends to file for approval in China in 2026.
The appeal lies in where it acts. Finasteride and dutasteride lower DHT throughout the body, with the known sexual side effects. Pyrilutamide is supposed to intercept the same signal only at the hair root. What is rated here is the state of knowledge: there are large blinded trials, but the public knows their results only from the manufacturer’s announcements.
How it works
In hereditary hair loss, dihydrotestosterone (DHT) shrinks the hair follicles via the androgen receptor. Pyrilutamide occupies this receptor in the skin and displaces testosterone and DHT there, without changing how much of them is formed. In its principle of action it is therefore related to RU58841 and clascoterone, which act at the same receptor.
According to the manufacturer, the effect remains confined to the skin because little active substance penetrates the skin and what does reach the body is rapidly converted into weakly active breakdown products. There is no peer-reviewed publication on this.
What is well supported
- There are large blinded trials with placebo. Kintor has tested pyrilutamide in double-blind, placebo-controlled trials in China and the US with more than 1,600 men in total. The trials are registered on ClinicalTrials.gov, with hair count in the target area after 24 weeks as the primary objective.
- In the most recent phase 3 trial, pyrilutamide is clearly ahead of placebo. In 666 men, the 1 percent solution produced 15.33 more hairs per square centimeter after 24 weeks than at baseline, placebo 4.68. The difference of 10.65 hairs per square centimeter was highly statistically significant (p less than 0.0001); the 0.5 percent solution was just below at 9.78.
- One year of use without sexual side effects. In an open-label study over 52 weeks, according to the manufacturer, few side effects occurred and no drug-related sexual dysfunction at all; 46 percent of participants had at least 10 more hairs per square centimeter.
What the studies show
Phase 2 in China (2020 to 2021)
120 men received, blinded, one of three pyrilutamide variants or placebo for 24 weeks. In September 2021, Kintor reported that the primary objective, the change in hair count in the target area compared with placebo, had been met with statistical significance, but gave no figures. The 0.5 percent solution was selected for further trials.
Phase 2 in the US (2022 to 2023)
123 men with moderate hair loss were allocated to three pyrilutamide groups and placebo. In the strongest group, hair count rose after 24 weeks by about 10 hairs per square centimeter compared with baseline (p equal to 0.0088). Compared with placebo, Kintor reported an improvement and a dose-response relationship, without quantifying the difference. Side effects were mostly mild scalp irritation, about as frequent as under placebo.
Phase 3 in China: the 2023 failure
740 men applied the 0.5 percent solution or placebo for 24 weeks. In November 2023, Kintor reported: hair count rose markedly under pyrilutamide compared with baseline, but compared with placebo there was only a trend at all time points, not a statistically significant difference. No serious side effects occurred.
The registration trial with 1 percent solution (2024 to 2026)
Kintor started a new trial with a higher concentration in two stages. In the phase 3 stage at 26 centers with 666 men, hair count after 24 weeks was 15.33 hairs per square centimeter above baseline under 1 percent, 14.46 under 0.5 percent and 4.68 under placebo. Both concentrations were highly statistically superior to placebo. According to the manufacturer, no drug-related serious side effects occurred, and side-effect rates did not differ meaningfully from placebo.
Long-term study over one year
In an open-label study without a control group at 16 centers in China, patients applied the 0.5 percent solution for 52 weeks. The primary objective was tolerability. Kintor reported a low rate of side effects, no deaths and no drug-related sexual dysfunction. In 46 percent, hair count rose by at least 10, and in 20 percent by at least 20 hairs per square centimeter.
Where the data stop
- No publication. All results come from Kintor’s stock exchange announcements. No trial has appeared in a peer-reviewed journal, no results are posted in the trial registry, and measures of variability, dropout numbers and side-effect frequencies are missing.
- Contradictory phase 3 results. In 2023, the 0.5 percent solution failed to separate from placebo in 740 men, and in 2026 it clearly did so in 666 men. Why cannot be assessed without the complete data.
- Size of the effect. Around 10 more hairs per square centimeter than under placebo is a measurable but moderate effect. There is no head-to-head comparison with finasteride or minoxidil.
- Women and the long term. For women there is only one phase 2 trial in China; for men, tolerability data cover one year at most.
Status, approval and legal
Pyrilutamide is not approved as a medicine anywhere. According to its own statements, Kintor has completed the phase 3 trials in China, intends to file for approval with the Chinese drug regulator in 2026 and expects approval in 2027. A trial on the combination with minoxidil is also planned. No approval procedure is known to be under way in the EU.
In parallel, Kintor sells cosmetics under the KOSHINÉ brand with KX-826 as the main active ingredient, including a serum against hair loss, mainly via online retail in China. In sport, pyrilutamide, as a non-approved substance, falls under S0 according to the wording of the WADA Prohibited List and is therefore prohibited at all times.
Safety
According to the manufacturer, pyrilutamide was well tolerated in all trials: mostly mild scalp irritation, about as frequent as under placebo, no drug-related serious side effects and, in the one-year study, no drug-related sexual dysfunction.
This cannot be checked independently because no frequencies have been published. Whether pyrilutamide has hormonal effects in the body, for example on libido or breast tissue, was captured only through the side-effect reports of the trials. Data on use over more than one year, in pregnancy or when trying to conceive are missing.
BK-Score Thin human evidence
| Human evidence | 5 | |
|---|---|---|
| Mechanism | 5 | |
| Safety data | 4 | |
| Hype gap | 5 | |
| Track record of use | 4 |
Evidence 5, because several double-blind, placebo-controlled trials with more than 1,600 men in total are available and the most recent phase 3 stage with 666 men reports a difference of 10.65 hairs per square centimeter from placebo (Kintor 2026), but the first phase 3 trial with 740 men showed no significant difference from placebo in 2023 and all results come only from stock exchange announcements, without peer-reviewed publication. Mechanism 5, because blocking the androgen receptor is an established principle of action, but the statements on low absorption through the skin and rapid breakdown come only from the manufacturer. Safety 4, because tolerability was recorded in controlled trials over 24 weeks and in an open-label study over 52 weeks, but was reported only in summary form without frequencies; the axis rates the data, not the danger. Hype 5, because pyrilutamide is touted in hair-loss forums as finasteride without side effects; the measured effect is real but moderate, and tolerability has not been independently verified. Use 4, because human experience comes from trials and from the manufacturer’s cosmetic products, without medical use and without a reporting system. Direction mixed: one failed and one successful phase 3 trial, both unpublished so far.
The score rates the state of knowledge, not the substance. “Safety data 9” means well studied – not harmless. “Track record of use 9” means used long and widely – that is not proof of efficacy.
Subjective assessment by Biohacking Kompakt based on published scoring rules – not a scientific rating and not a medical recommendation. Rules and all ratings (German)
Frequently asked questions about pyrilutamide (KX-826)
What is pyrilutamide (KX-826)?
An androgen receptor antagonist from the Chinese manufacturer Kintor that is applied to the scalp as a solution. There it blocks the hormone signal that shrinks the hair follicles in hereditary hair loss. It is not approved anywhere.
How well does pyrilutamide work against hair loss?
In the most recent phase 3 trial with 666 men, the 1 percent solution produced 10.65 more hairs per square centimeter after 24 weeks than placebo. An earlier phase 3 trial with 740 men found no significant difference from placebo. Both results are known only from the manufacturer’s announcements.
Why did one phase 3 trial fail and another succeed?
That cannot be assessed from outside. In 2023, the 0.5 percent solution failed to separate from placebo in 740 men; in 2026 it did so in 666 men, together with the 1 percent solution. Without published data on the placebo effect, variability and trial conduct, the contradiction remains unresolved.
Does pyrilutamide have fewer side effects than finasteride?
This has never been compared directly. The manufacturer reports no drug-related sexual dysfunction in a one-year study and good tolerability in all trials. Frequencies of individual side effects have not been published.
Is pyrilutamide approved in Germany?
No. Pyrilutamide is not approved as a medicine anywhere in the world; Kintor intends to file for approval in China in 2026. In sport it is prohibited as a non-approved substance under S0 of the WADA list.
Related
- Related topicClascoterone (Winlevi / Breezula)
- Related topicRU58841
- Related topicDutasteride
- Related topicFinasteride
- Related topicMinoxidil
- Related topicKetoconazole shampoo for hair loss
Sources
- ClinicalTrials.gov NCT05218642 – phase 2 trial of KX-826 versus placebo in the US, 123 men, 24 weeks
- ClinicalTrials.gov NCT06126965 – phase 3 trial of KX-826 0.5 % versus placebo in China, 740 men
- ClinicalTrials.gov NCT06622824 – phase 2/3 registration trial of KX-826 0.5 % and 1.0 % versus vehicle solution in China
- Kintor Pharmaceutical, stock exchange announcement of September 8, 2021 – phase 2 trial in China with 120 men, primary objective met
- Kintor Pharmaceutical, stock exchange announcement of May 11, 2023 – phase 2 trial in the US, 123 men
- Kintor Pharmaceutical, stock exchange announcement of November 27, 2023 – phase 3 trial in China without significant difference from placebo
- Kintor Pharmaceutical, stock exchange announcement of March 20, 2025 – open-label long-term safety study over 52 weeks
- Kintor Pharmaceutical, stock exchange announcement of March 18, 2026 – phase 3 stage of the registration trial with 666 men, primary objective met
- Kintor Pharmaceutical, interim report of August 19, 2026 – approval application planned for 2026, cosmetics with KX-826
- WADA Prohibited List 2026, NADA informational translation (German) – S0 non-approved substances
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Information only, not medical advice and not a usage or dosage recommendation. Prescription-only and unapproved substances belong in the hands of a physician. Last updated: 2026-10-07.