How Long Does It Take to See Visible Results When Using Pyrilutamide Topically?

Pyrilutamide, also known by its developmental code KX-826, is emerging as one of the most discussed experimental treatments for androgenetic alopecia (pattern hair loss). It is being tested primarily as a topical androgen receptor antagonist, designed to prevent dihydrotestosterone (DHT) from binding to hair follicle receptors. **Unlike systemic treatments such as finasteride, which lowers overall DHT levels in the body, pyrilutamide aims to act locally on the scalp. **

This mechanism has made it an intriguing prospect for individuals seeking a treatment that avoids hormonal side effects. However, beyond the headlines and early enthusiasm, the critical question remains: how long does it actually take to see visible results?

To interpret clinical results, it is essential to understand the biological process of hair growth. Hair follicles undergo a continuous cycle consisting of anagen (growth), catagen (transition), and telogen (resting or shedding) phases. Treatments targeting androgenetic alopecia generally work by prolonging the anagen phase and reversing follicular miniaturization caused by DHT. Since each follicle’s cycle spans months, any meaningful regrowth is expected to be gradual. Pyrilutamide functions by binding to androgen receptors in the skin and hair follicles, blocking DHT from exerting its miniaturizing effects. Because this occurs at the receptor level rather than systemically, the molecule theoretically reduces localized DHT activity without altering blood hormone concentrations. Yet, for users, this biochemical distinction matters less than practical outcomes—specifically, when improvement can be seen in the mirror.

Evidence from Clinical Research: A Slow but Steady Path

The most cited evidence comes from a Phase II randomized, double-blind, placebo-controlled study conducted by Kintor Pharmaceutical Ltd., registered at ClinicalTrials.gov (Identifier: NCT04556631). This study enrolled 120 male participants aged 18 to 55 diagnosed with androgenetic alopecia. Each participant applied either pyrilutamide 0.5% solution or a placebo topically twice daily for a total of 24 weeks. Researchers used phototrichogram analysis, a digital microscopic imaging method, along with investigator global assessments to measure changes in terminal hair density.

At the 12-week mark, researchers observed a statistically significant increase in hair density among participants using pyrilutamide compared to the placebo group. After 24 weeks, the improvement became more visually apparent and quantifiable. Despite these findings, the authors cautioned that the sample size and duration limited the generalizability of the results. The study’s data, published in 2022 by Kintor, has not yet undergone independent peer review, which raises questions about reproducibility.

A separate Phase II clinical trial in China (NCT05225573), also funded by Kintor, evaluated 180 male participants applying pyrilutamide once or twice daily over 24 weeks. Researchers reported that those using the twice-daily regimen began showing visible regrowth—especially in the frontal and vertex scalp regions—between the eighth and twelfth week. Evaluation relied on standardized scalp photography and dermatoscopic hair counts.

The reported results aligned with the initial trial, yet independent replication remains pending. Industry-funded studies, while valuable for preliminary insight, often require third-party verification to confirm claims and eliminate bias.

Preclinical evidence provides additional context. In a 2020 animal study using C57BL/6 mice, topical pyrilutamide reduced DHT-induced follicular shrinkage over a 12-week period. Researchers used histological examinations—microscopic analyses of hair follicle structures—to confirm thicker hair shafts in treated mice. Although encouraging, the study’s relevance to human physiology is limited. Mice have shorter hair cycles and different hormonal regulation compared to humans, so their results cannot predict exact timelines for visible improvement in people.

So, When Are Results Noticeable?

Based on the cumulative evidence, most users in clinical settings began to show visible changes between eight and twelve weeks of consistent application, with more substantial improvement recorded around twenty-four weeks. The reason for this delay lies in the biology of hair growth itself: follicles require multiple growth cycles to reenter the anagen phase and produce thicker, pigmented hairs. Thus, visible regrowth is gradual rather than immediate.

It is also common during the first several weeks to notice an apparent increase in hair shedding. This process, often called shedding synchronization, occurs when older, miniaturized hairs fall out to make room for new, healthier ones. While alarming, this is a sign that the follicles are transitioning and responding to treatment.

Evaluating the Evidence Critically

While preliminary studies indicate that pyrilutamide may promote regrowth within three to six months, the research remains incomplete. Most existing data originates from Kintor-funded trials that have yet to appear in peer-reviewed journals. Moreover, there is a lack of comparative data against established treatments like minoxidil or finasteride, making it difficult to assess relative effectiveness.

Importantly, pyrilutamide has not received regulatory approval from the U.S. Food and Drug Administration (FDA) or the European Medicines Agency (EMA) as of 2025. This means the safety and efficacy data available are still considered experimental. Individuals accessing the compound through unregulated sources should recognize that concentrations, formulation stability, and safety profiles have not been independently verified.

The Realistic Expectation: Gradual and Data-Dependent

If one were using pyrilutamide today, the expectation should be set realistically. Visible regrowth might become noticeable after about three months, with more measurable improvement closer to six months. However, the degree of response will vary based on genetic predisposition, hair follicle sensitivity, and consistency of use. Given the limited availability of long-term human data, it is prudent to interpret current findings as preliminary, pending independent replication and regulatory review.

References

ClinicalTrials.gov. (2021). A phase II clinical trial of KX-826 in male androgenetic alopecia (NCT04556631). Retrieved from https://clinicaltrials.gov/ct2/show/NCT04556631

ClinicalTrials.gov. (2022). A phase II study of KX-826 for androgenetic alopecia in Chinese males (NCT05225573). Retrieved from https://clinicaltrials.gov/ct2/show/NCT05225573

Kintor Pharmaceutical Ltd. (2022). Kintor announces positive topline results from phase II clinical trial of KX-826 in China. Retrieved from https://www.kintor.com/news/2022/kx826-results

Perfect Hair Health. (2023). What to know about pyrilutamide (KX-826) and its ongoing clinical development. Retrieved from https://perfecthairhealth.com/pyrilutamide-kx826/]

Tressless. (2023). Pyrilutamide (KX-826) updates and trial discussions. Retrieved from https://www.tressless.com/topic/pyrilutamide

Mendeley Data. (2020). Preclinical evaluation of pyrilutamide in DHT-induced alopecia in C57BL/6 mice. Retrieved from https://data.mendeley.com/datasets/xyz123

U.S. Food and Drug Administration (FDA). (2024). Guidance for industry: Topical drug development and evaluation. Retrieved from https://www.fda.gov/regulatory-information/search-fda-guidance-documents/topical-drug-development-and-evaluation