Pyrilutamide, code name KX-826, is an investigational androgen receptor antagonist applied to the skin. Kintor Pharmaceutical, a Chinese biotech company listed in Hong Kong, is developing it as a scalp solution (a “tincture”) for androgenetic alopecia (male and female pattern hair loss) and as a gel for acne. The idea is to block androgens such as DHT at the hair follicle or oil gland without lowering hormone levels in the body, as oral finasteride does.
Pyrilutamide is not approved as a medicine anywhere. In March 2026 Kintor reported that a pivotal phase 3 trial in Chinese men met its main goal, after an earlier phase 3 at a lower strength missed its comparison with placebo in 2023. Kintor said in August 2026 that it plans to file for approval in China in the second half of 2026. Nearly all efficacy results come from company stock-exchange announcements. As of October 2026 no pyrilutamide trial had been published in a peer-reviewed journal, and no results have been posted on ClinicalTrials.gov.
This page summarizes what the trial registrations and Kintor’s own exchange filings report. It is for education only and is not medical advice.
| Property | Detail |
|---|---|
| Drug class | Nonsteroidal androgen receptor antagonist, topical |
| Developer | Kintor Pharmaceutical (Suzhou Kintor), HKEX: 9939 |
| Route and forms | Scalp tincture (hair loss); gel (acne) |
| Studied strengths | 0.25%, 0.5% and 1.0%, once or twice daily, in phase 2 and 3 trials |
| Half-life | Not published (measured in phase 1, but results not released) |
| Key mechanism claim | Competes with androgens for the receptor in skin; company says it breaks down quickly into weakly active metabolites |
| Approval status | Not approved; China NDA planned for the second half of 2026 (company statement, August 2026) |
| Other sales | Sold since 2024 as a cosmetic ingredient (KOSHINÉ brand), not as a drug |
| WADA | Not named; as an unapproved drug it falls under S0 (non-approved substances) |
What it is
Pyrilutamide blocks the androgen receptor, the protein that testosterone and DHT bind to in order to act on cells. In hair follicles that are genetically prone to balding, androgen signaling shrinks the follicle over time, so thick hairs are replaced by fine, short ones. Kintor describes pyrilutamide as working by competing with androgens to bind the androgen receptor in the target tissue (Kintor, March 2026).
This works one step later than the drugs already used for hair loss:
- Finasteride and dutasteride block 5α-reductase, the enzyme that makes DHT, and lower DHT throughout the body.
- Minoxidil works through a different, non-hormonal mechanism.
- Pyrilutamide leaves hormone levels alone and blocks the receptor where it is applied.
The closest relative in practice is clascoterone, a steroidal topical androgen receptor inhibitor sold for acne as Winlevi and being developed as a stronger solution for hair loss. Kintor’s March 2026 filing notes that Cosmo Pharmaceuticals’ topical drug targeting the same receptor reported positive phase 3 results in December 2025. Pyrilutamide is also related in concept to the unapproved research chemical RU-58841 and, more distantly, to oral antiandrogens such as bicalutamide, which act on the same receptor throughout the body.
Kintor has not published the structure of KX-826 in a peer-reviewed paper. Its cosmetic ingredient (INCI) name is “Methylpyridinyl Fluoromethoxybenzonitrile Dimethyloxothiooxoimidazolidine” (Kintor, June 2024). Kintor’s filings give its core patent as valid until 8 September 2030 (Kintor interim results, August 2026).
How it behaves in the body
Very little has been published. Two phase 1 trials in US men with androgenetic alopecia were registered with pharmacokinetic outcomes (peak level, exposure and half-life), but their results have not been posted or published:
| Trial | Design | Doses on the scalp | n |
|---|---|---|---|
| NCT04984707 | Single ascending dose vs placebo | 3, 12, 48 and 96 mg once | 40 |
| NCT04502901 | Multiple ascending dose vs placebo, 14 days | 2.5, 5, 10 and 20 mg daily | 40 |
Kintor announced completion of the multiple-dose study in August 2020 and said it expected to release the data (Kintor, August 2020). No figures followed in its later filings.
Kintor states that the drug’s effect “is limited to local skin with low transdermal absorption” and that it is rapidly metabolized to low-activity compounds (Kintor, March 2026). These are company claims. No blood levels, half-life or hormone measurements in people have been made public to check them.
Regulatory status
- China: The pivotal phase 2/3 trial of the 1.0% tincture finished in the first half of 2026. In its August 2026 interim results, Kintor said it plans to submit the new drug application (NDA) to Chinese regulators in the second half of 2026 and expects a decision in the second half of 2027 (Kintor interim results, August 2026).
- United States and EU: No approval or filing. After the US phase 2 in 2023, Kintor said it intended to start phase 3 in the US or globally (Kintor, May 2023). No US phase 3 trial is registered on ClinicalTrials.gov.
- Cosmetics: In 2024, after KX-826 got its INCI name, Kintor began selling cosmetics with KX-826 as the main ingredient, starting with an anti-hair-loss scalp solution (Kintor, July 2024). They are sold under the KOSHINÉ brand, and Kintor reported RMB 52.0 million in cosmetics and raw-material sales for the first half of 2026 (Kintor interim results, August 2026). These products have not been reviewed or approved as medicines. Kintor’s announcements do not say how much KX-826 they contain or how they compare with the trial formulations.
What the research shows
Kintor has run at least eight trials in hair loss and one in acne. The table below lists the ones with reported results. Unless marked otherwise, every result here is company-reported through Hong Kong Stock Exchange announcements. None has been peer reviewed, and none of the registry entries has posted results.
Hair-loss trials at a glance
| Trial | Population | Arms | Reported 24-week result (TAHC) |
|---|---|---|---|
| China phase 2 (NCT05940506) | 120 men | 0.25% BID, 0.5% QD, 0.5% BID, placebo | “Met primary endpoint”; no numbers released |
| China phase 2, women (NCT06409650) | 160 women | 0.25% and 0.5%, QD and BID, placebo | 0.5% QD: +11.39 hairs/cm² vs placebo (P = 0.0087) |
| US phase 2 (NCT05218642) | 123 men | Three active doses, placebo | 0.5% BID: ≈ +10 hairs/cm² vs baseline; placebo difference not stated as significant |
| China phase 3 (NCT06126965) | 740 men | 0.5% BID, placebo | Not significant vs placebo |
| China phase 2/3, phase 2 stage (NCT06622824) | 90 men | 0.5% BID, 1.0% BID, vehicle | +13.66 (0.5%) and +13.14 (1.0%) hairs/cm² vs placebo |
| China phase 2/3, phase 3 stage (same trial) | 666 men | 0.5% BID, 1.0% BID, vehicle | +9.78 (0.5%) and +10.65 (1.0%) hairs/cm² vs placebo (both P under 0.0001) |
TAHC (target area hair count) is the number of non-vellus hairs (hairs thicker than fine “peach fuzz”) counted in a marked patch of scalp, reported per cm². It is the standard primary endpoint in hair-loss trials. QD means once daily and BID twice daily.
Men: the early phase 2 trials
The first efficacy trial randomized 120 Chinese men to three doses or placebo for 24 weeks. Kintor announced in September 2021 that it met its primary endpoint (change in TAHC vs placebo) and chose the 5 mg (0.5%) dose for phase 3. Most adverse events were mild, and no serious adverse event occurred. Kintor promised detailed data once the study report was final, but the September 2021 announcement gave no hair counts (Kintor, September 2021).
The US phase 2 trial enrolled 123 men with Norwood-Hamilton stage III vertex to V hair loss: 93 to active doses and 30 to placebo (Kintor, May 2023). Kintor reported:
- the 0.5% BID group gained about 10 hairs/cm² from baseline at 24 weeks (P = 0.0088 vs baseline);
- an “improvement in TAHC versus placebo” and a dose-response trend, without a difference or P value against placebo;
- mostly mild adverse events, chiefly local scalp sensitivity, at rates similar to placebo, with no dropouts for adverse events.
The registered primary endpoint was the change in TAHC, and the comparison that matters in a placebo-controlled trial is the gap to placebo. The announcement does not state that this gap was statistically significant. The arm descriptions also differ: the registry lists 2.5 mg twice daily, while the announcement says 0.25% once daily.
Men: the phase 3 that missed
The first Chinese phase 3 randomized 740 men to 0.5% twice daily or placebo for 24 weeks. In November 2023 Kintor reported that the drug group grew hair compared with its own baseline (P under 0.0001). Compared with placebo, TAHC was better at all visits but not statistically significant, which Kintor described as “a trend in efficacy” (Kintor, November 2023). No serious adverse events were reported. This is the main efficacy result that did not hold up. Gains from baseline alone say little, because placebo groups also gain hair: in the later 1.0% trial, placebo groups gained 4.68–8.73 hairs/cm².
Men: the 1.0% phase 2/3 trial
Kintor then ran a new phase 2/3 trial in Chinese men aged 18–49 with a “seamless” adaptive design. A phase 2 stage was used to confirm doses, and the phase 3 stage then went ahead without changes to the arms or sample size (NCT06622824; Kintor, July 2025). The registry entry has not been updated and still reads “not yet recruiting.”
| Stage | n | Arm | TAHC change from baseline | Difference vs placebo | P |
|---|---|---|---|---|---|
| Phase 2 stage | 90 | 0.5% BID | +22.39 hairs/cm² | +13.66 | 0.002 |
| Phase 2 stage | 90 | 1.0% BID | +21.87 hairs/cm² | +13.14 | 0.004 |
| Phase 2 stage | 90 | Placebo | +8.73 hairs/cm² | — | — |
| Phase 3 stage | 666 | 1.0% BID | +15.33 hairs/cm² | +10.65 | under 0.0001 |
| Phase 3 stage | 666 | 0.5% BID | +14.46 hairs/cm² | +9.78 | under 0.0001 |
| Phase 3 stage | 666 | Placebo | +4.68 hairs/cm² | — | — |
The phase 3 stage ran at 26 centers for 24 weeks, followed by 14 days of safety follow-up (Kintor, March 2026). Kintor reported no drug-related serious adverse events and no clinically significant difference in adverse-event rates between groups, but gave no rates. The results were presented at the World Congress for Hair Research in May 2026 (Kintor, June 2026).
The two strengths gave nearly the same result (10.65 vs 9.78 hairs/cm² over placebo). In this trial, the 0.5% dose that failed in the 2023 phase 3 beat placebo. The filings do not explain why. Possible reasons include differences in population, placebo response or the trial itself, and these cannot be judged without the full data.
Women
A Chinese phase 2 trial enrolled 160 women with Savin scale D3–D6 hair loss (119 on one of four active regimens and 41 on placebo). At 24 weeks, the 0.5% once-daily arm gained 11.39 hairs/cm² more than placebo (P = 0.0087), and Kintor reported an effect by week 12 (Kintor, December 2022). Results for the other three arms were not given. Kintor said most adverse events were mild and similar to placebo. No phase 3 trial in women is registered.
Long-term and combination data
- 52-week safety study. This open-label study at 16 Chinese centers used 0.5% twice daily. Kintor reported a low overall adverse-event rate, no deaths and “no drug-related sexual dysfunction adverse reactions” (Kintor, March 2025). At 52 weeks, 46% of the target population had gained at least 10 hairs/cm² and 20% at least 20 hairs/cm². The number enrolled and the adverse-event rates were not given, and with no control group the hair counts cannot be separated from placebo-type effects.
- With minoxidil. In an open-label study at two Chinese hospitals, 75 men were randomized to 5% minoxidil twice daily with or without 0.5% pyrilutamide twice daily. At 24 weeks the combination group gained 30.54 hairs/cm², which was 10.29 hairs/cm² more than minoxidil alone (P = 0.0075) (Kintor, May 2025). The study was small and not blinded. Kintor plans a phase 1b/3 combination trial.
Acne
A Chinese phase 2 trial randomized 160 men and women with mild to moderate acne to 0.25% or 0.5% gel (once or twice daily) or placebo for 12 weeks (Kintor interim results, August 2026). The planned primary endpoint was treatment success on the investigator’s global assessment (IGA) scale at week 12 (Kintor, January 2022). Kintor’s summary does not say the primary endpoint was met. It reports that:
- every patient who reached treatment success was in a drug group, with no numbers or P value;
- lesion counts improved significantly vs placebo only in a post hoc subgroup (an analysis chosen after the data were in) of patients with at least 30 non-inflammatory lesions at baseline.
Kintor says these results “will lay the foundation” for future studies. No further acne trial with pyrilutamide has been announced. Kintor’s later acne work has focused on a different compound, GT20029.
Animal data
In a 2026 study, researchers at China Pharmaceutical University and Simcere Pharmaceutical used 0.5% pyrilutamide as the active comparator in a mouse hair-growth model, and reported that their own lead compound matched it with an earlier onset (14 vs 21 days) (Zhang et al., J Med Chem 2026). This is animal data and says nothing about effects in people.
Independent assessments
Published reviews mention pyrilutamide only briefly, because there are no peer-reviewed trial reports to evaluate. A 2023 review listed it as a topical androgen receptor antagonist under study for male pattern hair loss (Saceda-Corralo et al., Am J Clin Dermatol 2023). A 2026 review summarized its phase 3 record as “mixed” and called for rigorous, standardized trials of new hair-loss drugs (Burshtein et al., Front Pharmacol 2026).
Side effects and risks
What the trials report
Kintor’s announcements describe the same picture in every trial: mostly mild, local scalp reactions at rates similar to placebo, no deaths, and no serious adverse events attributed to the drug. Kintor has not released adverse-event percentages, laboratory data or hormone measurements for any trial. The safety record therefore cannot be judged independently.
Kintor’s product page for KX-826 lists itching, contact dermatitis and mild skin irritation as possible reactions, and warns that the solution can burn and irritate the eyes (Kintor KX-826 page).
Systemic antiandrogen effects
Androgen receptor blockers taken by mouth, such as bicalutamide, act throughout the body and have hormonal side effects. Whether a topical product causes any depends on how much reaches the blood, and those data are not public. Kintor reports no drug-related sexual side effects in the 52-week study or in the phase 2 stage of the 1.0% trial. Without published rates or blood levels, these reports cannot be checked.
Who was not studied
Trials enrolled adults only (18 and older), and the 1.0% trial capped age at 49. There are no data in pregnancy, breastfeeding or adolescents. Kintor’s own product page asks children, pregnant and breastfeeding women and people over 65 to consult a doctor before use. Interactions with other scalp products have not been studied, apart from the combination study with minoxidil.
Cosmetic products
Cosmetics with KX-826 are sold online. They are not approved medicines, and their strength and formulation may differ from the tincture used in trials. Any “pyrilutamide” sold outside Kintor’s channels has no verified identity, strength or purity.
Legal status and sport
Pyrilutamide is not a controlled substance in the US: it is not named in the Schedule III anabolic steroid list (21 CFR 1308.13), and it is an antiandrogen, not an anabolic agent. WADA’s 2026 list does not name it. However, S0 prohibits at all times any substance not covered elsewhere on the list that has “no current approval by any governmental regulatory health authority for human therapeutic use,” including drugs in clinical development (WADA 2026 Prohibited List). As written, that covers pyrilutamide until it is approved somewhere.
Key takeaways
- Investigational only. Pyrilutamide is a topical androgen receptor blocker with no drug approval anywhere. Kintor plans to file in China in the second half of 2026.
- Results are company-reported. Every efficacy figure comes from Kintor’s exchange filings. No trial has been peer reviewed, and no registry has posted results.
- Mixed phase 3 record. The 0.5% phase 3 missed against placebo in 2023. The 2026 phase 3 stage of a new trial reported about 10 more hairs/cm² than placebo for both the 0.5% and 1.0% strengths.
- Little evidence for acne. The acne phase 2 reported benefit only in a post hoc subgroup.
- Safety data are thin. Kintor reports mild local reactions and no drug-related sexual side effects, but has not released rates, blood levels or hormone data.
- The cosmetic is not the drug. KX-826 is already sold in cosmetics, which have not been reviewed as medicines and have undisclosed strength.
Sources
- Kintor Pharmaceutical. Voluntary announcement: completion of phase Ib clinical trials of pyrilutamide (KX-826) in the United States. HKEX, August 4, 2020. HKEX.
- Kintor Pharmaceutical. Voluntary announcement: phase II clinical trial of pyrilutamide (“KX-826”)’s treatment of AGA in China reached primary endpoint. HKEX, September 8, 2021. HKEX.
- Kintor Pharmaceutical. Voluntary announcement: dosing of first patient for acne vulgaris phase II clinical trial of KX-826 in China. HKEX, January 24, 2022. HKEX.
- Kintor Pharmaceutical. Voluntary announcement: phase II clinical trial of KX-826 for treatment of female AGA in China met primary endpoint. HKEX, December 1, 2022. HKEX.
- Kintor Pharmaceutical. Voluntary announcement: successful completion of phase II clinical trial of KX-826 for treatment of AGA in the United States. HKEX, May 11, 2023. HKEX.
- Kintor Pharmaceutical. Inside information: results of KX-826 phase III clinical trial for treatment of male AGA in China. HKEX, November 27, 2023. HKEX.
- Kintor Pharmaceutical. Voluntary announcement: KX-826 received the INCI designation. HKEX, June 4, 2024. HKEX.
- Kintor Pharmaceutical. Voluntary announcement: cosmetics with KX-826 as the main ingredient launch to market. HKEX, July 10, 2024. HKEX.
- Kintor Pharmaceutical. Voluntary announcement: long-term safety phase III clinical trial of KX-826 for the treatment of AGA reached primary endpoint. HKEX, March 20, 2025. HKEX.
- Kintor Pharmaceutical. Voluntary announcement: superior efficacy of clinical observational study in KX-826 in combination with minoxidil for the treatment of male adults with AGA in China over minoxidil monotherapy. HKEX, May 2, 2025. HKEX.
- Kintor Pharmaceutical. Voluntary announcement: phase II stage of pivotal clinical trial of KX-826 tincture 1.0% for the treatment of male adult AGA in China reached primary endpoint. HKEX, July 24, 2025. HKEX.
- Kintor Pharmaceutical. Voluntary announcement: phase III stage of pivotal clinical trial of KX-826 tincture 1.0% for the treatment of male adult AGA in China reached primary endpoint. HKEX, March 18, 2026. HKEX.
- Kintor Pharmaceutical. KX-826 phase III clinical trial and combination therapy study data for AGA presented at the 2026 World Congress for Hair Research (WCHR 2026). Company news, June 1, 2026. Kintor.
- Kintor Pharmaceutical. Interim results announcement for the six months ended 30 June 2026. HKEX, August 19, 2026. HKEX.
- Kintor Pharmaceutical. KX-826 androgen receptor antagonist (product page). Kintor.
- Suzhou Kintor Pharmaceutical. KX-826 trial registrations: phase 1 single ascending dose, NCT04984707; phase 1 multiple ascending dose, NCT04502901; China phase 2 (men), NCT05940506; US phase 2 (men), NCT05218642; China phase 3 (men), NCT06126965; China phase 2 (women), NCT06409650; China phase 2/3 (men, 1.0%), NCT06622824. ClinicalTrials.gov.
- Saceda-Corralo D, Domínguez-Santas M, Vañó-Galván S, Grimalt R. What’s new in therapy for male androgenetic alopecia? Am J Clin Dermatol. 2023;24(1):15–24. PubMed.
- Burshtein J, Burshtein A, Schlesinger T. Emerging pharmacotherapies and regenerative solutions for promoting hair growth for androgenetic alopecia. Front Pharmacol. 2026;17:1776134. PubMed.
- Zhang Y, Zhang W, Tang F, et al. Novel dual soft drug strategy enables development of topical androgen receptor antagonists with enhanced efficacy and optimized safety for androgenetic alopecia. J Med Chem. 2026;69(14):16428–16454. PubMed.
- World Anti-Doping Agency. World Anti-Doping Code International Standard: Prohibited List 2026. WADA 2026 Prohibited List.
- US Code of Federal Regulations. 21 CFR 1308.13, Schedule III. 21 CFR 1308.13.