STUDresearch · Non-peptide
Pyrilutamide
Also known as
KX-826 · KX826 · Kintor topical AR antagonist · pyrilutamide 0.5% · pyrilutamide 1%
Community talk. May be wrong. Not medical advice. Not a protocol. Not for human or animal use.
Non-peptide
Some talk
Local
Topical
Skin, hair & tissue remodeling
Topical androgen-receptor blocker aimed at the follicle.
What people say
Pyrilutamide (KX-826) is an investigational nonsteroidal androgen-receptor antagonist formulated as a topical scalp solution; it is distinct from finasteride, minoxidil and RU-58841.
Doses people talk about
These are formulation concentrations and reported frequencies, not a progression. Trial tinctures and group-buy or imported products cannot be assumed equivalent.
How it may feel
Reports conflict. One six-person group relayed no negative effects by six weeks; another user described systemic-like symptoms within a week. Longer hair reports ranged from claimed regrowth to no difference in a one-temple comparison.
Six-person group report0.5% topical once daily; one 1.0% daily
At six weeks the poster relayed no negative effects; identity, denominator and outcomes were not independently verified.
China Phase III arms0.5% or 1.0% topical BID
Both concentrations were applied twice daily for 24 weeks in 666 Chinese adult men; figures are company topline.
Half-life & effect duration
- Half-life in the body
- Topical KX-826No settled estimate
- Felt duration people report
- Adverse accountSymptoms within about 1 week; resolved 5 days after stopping
- Other accountNo adverse effects at 6 weeks
- Hair assessmentsAcross 1–7 months
Cycles people discuss
Trial and community discussion treats use as continuing maintenance, not a short cycle. China Phase III evaluated BID use for 24 weeks; community photo updates usually span months.
Timing
Formal trials used once- or twice-daily topical schedules, with the selected Phase II and later Phase III arms using BID. Those schedules are study designs, not a parent-drug half-life or a recommendation for unverified products.
Stacks
Reports commonly combine pyrilutamide with minoxidil or a 5-alpha-reductase inhibitor, confounding hair changes and adverse effects. RU-58841 is usually discussed as an alternative.
Watch for
Scalp sting / dryness from the alcohol vehicle.
Tap a line to jump into the full notes. Research only — may be wrong.
Timing context & sources
Half-life in the body
A terminal human parent-drug half-life was not established in the reviewed KX-826 sources.
The male Phase II company report says systemic KX-826/metabolite exposure reached steady state after 14 days, but gives no terminal estimate. BID efficacy arms do not supply one.
Company reports describe low blood concentrations without a full analyte-specific PK table; an absent value here does not prove none exists elsewhere.
- Kintor Pharma — China Phase II KX-826 results (opens in a new tab)120 Chinese adult men received 0.25% BID, 0.5% QD, 0.5% BID or vehicle; 0.5% BID improved week-24 TAHC 15.34 hairs/cm² versus placebo. Exposure reached steady state after 14 days.Company report without a full peer-reviewed analyte-specific PK table or terminal half-life.
- Kintor Pharma — Phase III KX-826 tincture 1.0% for AGA reached primary endpoint (opens in a new tab)18 March 2026 company release: 666 Chinese adult men, 24 weeks; 1.0% BID +15.33 hairs/cm², 0.5% BID +14.46, vehicle +4.68; placebo-adjusted differences 10.65 and 9.78.Company topline rather than a peer-reviewed full paper; short follow-up and Chinese male AGA population limit generalization.
Felt duration people report
The inspected reports do not establish a consistent onset or per-application felt-duration window.
Reports ranged from no adverse effects at six weeks to systemic-like symptoms within about one week and resolving five days after discontinuation; hair assessments occurred over one to seven months.
Anonymous unblinded reports used unverified products, often with minoxidil, and cannot establish causality, prevalence or a pharmacodynamic clock.
- Reddit r/tressless — No side effects on pyrilutamide so far (opens in a new tab)Poster relayed six-person, six-week use: most 0.5% daily, one 1% daily, no reported sexual/other negative effects, and only fine vellus hairs.One anonymous relay; group-buy product and claimed lab result were not independently verified; sparse outcome follow-up.
- Reddit r/tressless — 29M seven-month pyrilutamide update (opens in a new tab)Author added once-daily KX-826 after long-term minoxidil, reported a day-30–40 shed then new hair; another commenter reported no difference after five months of 0.5% BID on one temple.Anonymous, uncontrolled, unverified products; continued minoxidil and informal within-person comparison confound attribution.
- Reddit r/tressless — Does pyrilutamide cause short-term shedding? (opens in a new tab)One commenter reported less loss/growth, then fin/dut-like symptoms after about one week, persisting about three weeks during use and resolving five days after stopping.Anonymous retrospective report, no examination, rechallenge, product assay or denominator.
What people say
- Itch / shed: “Almost instantly stops my scalp itch and cuts shedding” — a 5-month photo thread. anecdote
- Add-on after minox: 7-month update: shed at day 30–40 after adding KX, then hair in spots minox had not touched. anecdote
- 0.5% ≈ 1% clinically in some 2026 reads of the Phase 3 pair — people use that to stay at 0.5% for sides. forum
- China Phase 3 (2026 topline): 1% BID +15.33 hairs/cm² from baseline (~+10.7 over placebo); 0.5% BID +14.46 (~+9.8 over placebo); placebo +4.68. 52-week, 666-patient-class story. Company numbers, not a paper yet. trial
Doses people talk about
- Community: 0.5% once or twice daily is the imported bottle. 1% when they can get it. forum
- Not an oral. Swallowing KX is not the logbook. forum
- Framing: Trial tincture % and r/tressless bottles — not a prescription. forum
- Phase 3 pair: 0.5% or 1.0% tincture twice daily. trial
- Older Phase 2: 0.5% BID was the arm that moved; 0.25% and once-daily arms were weaker. trial
How it may feel
- Early reports conflict: A six-person group-buy post said most used 0.5% daily for six weeks without reported sexual or other negative effects, while a separate user described finasteride- or dutasteride-like symptoms within about a week that resolved five days after stopping. Products were unverified. forum
- Days 30–40: Switch/add-on shed shows up in logs. Same emotional tax as a minox start. forum
- Months 3–7: Photo-thread window. Some “it did nothing” on TRT 120 mg/week + 0.5% once daily — dose/frequency gets blamed. forum
- Sides that are not supposed to happen: 0.5% BID logs of low libido and nipple sensitivity. The “it’s only topical” story is not clean. forum
- Months 6–12: Stay-on culture like minox. Stopping talk is thin because the product is still gray/import for a lot of users. forum
Cycles people discuss
- Daily topical, stay on — same forever logic as minox if it is doing anything. forum
- 52-week trial window is the long official look. trial
Timing
- Systemic leak: Nipple/libido logs imply some gets in. How much is argued, not measured in those posts. forum
- Topical, twice daily in the winning arms. Local receptor occupancy is the point; a blood t½ is not what r/tressless compares. trial
- Why schedules differ: Male Phase II selected 0.5% BID, and both 0.5% and 1.0% BID met the later Phase III endpoint. Those schedules do not establish a parent-drug half-life. trial
More on what it is
- Why people talk about it: r/tressless treat it as the “real” RU-58841 — company trials, Phase 3 numbers, less cowboy lore. 2026 China Phase 3: +15.33 hairs/cm² on 1% BID vs +4.68 placebo. forum
- Vs RU: 2026 threads: “KX-826 is better than RU — we have safety data.” RU stays the gray bottle. forum
- Vs fin/dut: Different enzyme vs receptor. People add KX when fin “does nothing” or when they will not swallow a 5-AR. forum
- What it is: Kintor’s topical nonsteroidal AR antagonist (KX-826). Tincture 0.5% or 1.0%, usually twice daily in the trials people quote. Not a 5-AR inhibitor. Not minoxidil. Not FDA-approved (China Phase 3 hit in 2026; US still behind). trial
- How it works (plain): Blocks androgen at the receptor in the scalp so DHT has a harder time shrinking the follicle — without (in the pitch) crushing serum DHT like dut. trial
Stacks
- + minoxidil (oral or topical) — the usual add. forum
- + fin or dut — receptor block on top of 5-AR, or KX instead. forum
- Vs RU, not with it for most. forum
- Microneedling — same hair-stack culture. forum
Storage notes
- Finished liquid from a vendor or compounding talk. Alcohol vehicle. Keep away from kids/pets. forum
- No bac-water chart. forum
Watch for
- Scalp sting / dryness from the alcohol vehicle. forum
- Shed at ~month 1 when added. forum
- Libido / nipple sensitivity on 0.5% — logged, which undercuts “zero systemic.” forum
- Palpitations in a minority “this stuff is dangerous” thread — messy, stacked, not a trial AE table. anecdote
- Import quality: Same gray-market problem as RU, with a nicer brochure. forum
- On TRT: One log of 0.5% daily + 120 mg/week T = no hair change. Androgen load vs topical block is the argument. anecdote
- Not FDA-approved. China Phase 3 is company topline. trial
Evidence mix
Mostly community / anecdote tags
Full: every bullet (trial + community). Use Scan for a faster bro-science read.