Can Pyrilutamide Be Used by Both Men and Women, or Only in Specific Cases?

Understanding whether pyrilutamide can be used safely and effectively by both men and women is essential for anyone considering it for hair loss or skin disorders. Pyrilutamide (KX‑826) is still an investigational drug, meaning that even though it is widely discussed online, its evidence base is still developing. Because of this, a careful examination of the research is necessary. In this article, we explore the current scientific findings, explain the technical concepts in accessible language, and critically evaluate the limitations of the available research.

Pyrilutamide is a topical non‑steroidal anti‑androgen. Anti‑androgens are drugs that block the action of androgens, which are hormones such as testosterone and dihydrotestosterone (DHT). These hormones signal through the androgen receptor, a protein in cells that receives and translates hormonal messages. Pyrilutamide binds to these receptors in the skin and hair follicles, preventing androgens from triggering their usual biological effects. This mechanism is relevant because androgenetic alopecia (pattern hair loss) is strongly influenced by DHT, which progressively miniaturizes hair follicles.

The topical nature of pyrilutamide is intended to reduce systemic exposure, meaning that the drug is designed to work mainly where it is applied, with minimal absorption into the bloodstream. This detail is important for both men and women, as systemic anti‑androgens can have significant side effects.

Evidence From Male Clinical Studies

Clinical studies in men with androgenetic alopecia have generated mixed results. A Phase II trial conducted in the United States evaluated pyrilutamide in 123 adult male participants with moderate pattern hair loss over a 24‑week period using a randomized, double‑blind, vehicle‑controlled design.

The outcome measure was the change in non‑vellus hair count in a target area, assessed using macrophotography and phototrichogram techniques. In this study, the group using 0.5% pyrilutamide twice daily showed an increase of approximately ten terminal hairs per square centimeter over the 24‑week period. According to the sponsor's report, no serious adverse events occurred.

A separate Phase II trial conducted in China included 120 adult men randomized to receive either placebo or varying concentrations of pyrilutamide for 24 weeks. The highest efficacy was reported in the group receiving 0.5% twice daily, which showed a mean increase of 22.73 terminal hairs per square centimeter. The method again involved standardized macrophotography. This study also did not report serious adverse effects. However, the data were published in corporate disclosures rather than peer‑reviewed journals, which limits independent verification.

More recently, a Phase III trial failed to meet its primary endpoint. After 24 weeks, the increase in hair count in the pyrilutamide group did not differ significantly from the placebo group. This inconsistency suggests that the prior results may not be as robust as initially thought and highlights the need for independently reviewed research.

Evidence From Female Clinical Studies

Pyrilutamide has also been studied in women with female pattern hair loss. A Phase II multicenter, randomized, double‑blind study in China included 160 women aged eighteen years or older. Participants applied either placebo or varying doses of pyrilutamide daily for 24 weeks. The evaluation method mirrored that of the male studies, relying on macrophotography and phototrichogram measurements. In women using 0.5% once daily, the mean increase in non‑vellus hair count was reported to be 11.39 hairs per square centimeter more than placebo, a statistically significant result.

The safety profile reported in this study was favorable, with no severe drug‑related adverse events. However, as with the male studies, the available data have been reported primarily by the sponsor and presented at conferences rather than published in peer‑reviewed medical journals. This limits the ability to critically examine the data collection methods, statistical analyses, and possible biases.

Understanding the Technical Aspects of the Research

Phototrichograms, used throughout the studies, involve taking highly magnified and standardized photographs of a marked scalp area and counting the hairs within that region. Although this method is widely used in clinical trials, its accuracy depends heavily on operator technique, lighting, and calibration. When data come only from sponsor‑generated reports, independent researchers cannot assess the consistency of these measurements.

Another important detail is the trial population. Many of the studies enrolled adults with moderate androgenetic alopecia and excluded individuals with other scalp conditions, systemic diseases, or hormone‑related disorders. This means that the results may not apply to people who fall outside these criteria. The duration of all existing trials has been 24 weeks for primary outcomes. Because hair follicles grow in cycles lasting years, a six‑month study may not capture long‑term benefits or risks. A 52‑week safety study is ongoing, but its results have not yet undergone peer review.

Can Both Men and Women Use Pyrilutamide?

Based strictly on the research that has been made public, pyrilutamide is being developed for both men and women. Both sexes have been included as distinct trial populations, and the results suggest that pyrilutamide is active in reducing androgen signaling in hair follicles in both groups. However, the inconsistency in the male Phase III results, the lack of peer‑reviewed publications, and the limited duration of safety data all raise important questions. For women, the use of anti‑androgens carries additional concerns, particularly for those who are pregnant or may become pregnant, because fetal development is highly sensitive to hormonal disruption. Even low systemic absorption can be relevant in such cases.

Because pyrilutamide remains unapproved in major regulatory regions such as the United States, Europe, and many other countries, its use outside clinical trials carries inherent uncertainty for both men and women. This uncertainty comes not from a lack of promise but from incomplete data.

What We Still Need to Know

From a critical perspective, the most important unanswered questions include the extent of systemic absorption over long periods, the drug’s effects across different hormonal backgrounds, the durability of results beyond 24 weeks, and the reproducibility of findings in independent, peer‑reviewed studies. These are the issues that matter most to us as potential users because they determine not only whether pyrilutamide works but also whether it is safe over the long term. Until independently validated research becomes available, pyrilutamide should be viewed as an interesting and potentially valuable investigational therapy whose final role in treating pattern hair loss is not yet established.

References (APA 7)

Kintor Pharmaceutical. (2021). FDA greenlights Phase II clinical trial of pyrilutamide for androgenetic alopecia in the US. PR Newswire. Retrieved from https://www.prnewswire.com/news-releases/kintor-pharmaceutical-announced-fda-has-greenlighted-pyrilutamides-phase-ii-clinical-trial-for-androgenetic-alopecia-in-the-us-301331131.html

Kintor Pharmaceutical. (2022). Successful dosing of first batch of patients in acne vulgaris Phase III trial. PR Newswire. Retrieved from https://www.prnewswire.com/news-releases/kintor-pharmaceuticals-announced-successful-dosing-of-the-first-batch-of-patients-for-acne-vulgaris-phase-iii-clinical-trial-of-pyrilutamide-301270510.html

Hong Kong Stock Exchange. (2023). Kintor Pharmaceutical corporate filing. Retrieved from https://www1.hkexnews.hk/listedco/listconews/sehk/2023/0330/2023033004440.pdf

European Academy of Dermatology and Venereology. (2023). Hair and nail disorders abstracts, EADV Congress 2023. Retrieved from https://eadv.org/wp-content/uploads/scientific-abstracts/EADV-congress-2023/Hair-and-nail-disorders.pdf

Follicle Thought. (2023). Kintor begins Phase 3 trial for androgenic alopecia: Latest update. Retrieved from https://folliclethought.com/kintor-begins-phase-3-trial-for-androgenic-alopecia-latest-update