Pyrilutamide Once Daily vs Twice Daily: Three Trials Tested It and None Published

That is not a figure of speech. Pyrilutamide — KX-826, developed by Suzhou Kintor Pharmaceutical — has seven registered trials on ClinicalTrials.gov, and the results section is empty on all seven [1][2][3][4][5][6][7]. Everything the hair loss community believes about this drug's optimal schedule traces back to company statements about data that has never been posted to the registry or, as far as I can find, published in a peer-reviewed journal.

This article is about what the registry actually contains, because the registry is the part anybody can check.

The trials that tested the schedule directly

Three phase 2 trials included both a once-daily and a twice-daily arm. In each, the design is cleaner than it first looks.

NCT05940506 — China, phase 2, 120 participants, primary completion July 2021 [2]. Arms:

• 2.5 mg twice daily (0.25%)
• 5 mg once daily (0.5%)
• 5 mg twice daily (0.5%)
• Placebo

NCT05218642 — United States, phase 2, 123 men, primary completion February 2023 [1]. Arms:

• 2.5 mg twice daily
• 5 mg once daily
• 5 mg twice daily
• Matching placebo

NCT06409650 — China, phase 2, 160 female participants, primary completion November 2022 [3]. This one has the most complete factorial design of the three:

• 2.5 mg once daily
• 2.5 mg twice daily
• 5 mg once daily
• 5 mg twice daily
• Matching placebo once daily
• Matching placebo twice daily

Look at what the first two share. 2.5 mg twice daily and 5 mg once daily deliver the same 5 mg per day. The only variable between those two arms is whether the dose arrives in one application or two. That is a genuine schedule comparison, properly controlled, and it is rare — most dosing-frequency debates in this field are arguments about protocols nobody compared head-to-head.

The third trial goes further by running placebo in both schedules, which controls for the act of applying a topical twice rather than once — a real confounder, since mechanical scalp contact and vehicle exposure are not nothing.

The six-arm female trial deserves a second look, because running placebo in both schedules is a detail most sponsors skip and it closes a real hole. Applying a topical twice a day is not the same experience as applying it once — there is more vehicle on the scalp, more mechanical contact, more opportunity for the routine to be followed or abandoned. Without a twice-daily placebo you cannot separate the drug's schedule effect from the application's schedule effect. Somebody on that protocol team was thinking carefully.

The primary endpoint in all of them is the same and it is a good one: change from baseline in non-vellus target area hair count at 24 weeks, versus placebo [1][2][3]. Non-vellus TAHC counts terminal hairs in a square centimetre of scalp, typically on a 0–300 scale. It is the standard objective measure in this field, far better than photographs or self-report.

So the design is sound, the question is well-posed, the endpoint is objective, and the trials completed — the most recent of the three in February 2023, nearly three years ago.

No results posted [1][2][3].

The programme behind the phase 2 work

The two phase 1 trials are worth a paragraph, because they set the ceiling on what anyone can claim about safety.

NCT04984707 was a single ascending dose study in 40 healthy men with androgenetic alopecia, completing in April 2019 [7]. NCT04502901 followed as a multiple ascending dose study, also 40 participants, dosing once a day for 14 days and completing in August 2020 [6]. Both were topical, both were placebo-controlled, and between them they establish that the compound is tolerated on the scalp and characterise how much of it gets into circulation.

Two weeks of dosing in forty people is exactly the right size for a phase 1 and exactly the wrong size to tell you anything about a drug somebody might apply daily for a decade. That is not a criticism — it is what phase 1 is for. It is worth stating because "phase 1 showed it was safe" gets repeated about this compound as though it settled the long-term question, and the longest dosing period in either study was fourteen days.

Note also the schedule: the multiple-dose phase 1 ran once daily [6]. The programme started on a once-daily assumption, tested both schedules in phase 2, and arrived at twice daily. That trajectory is itself informative.

What the phase 3 programme reveals about the answer

Here is the part that does tell you something. There are two later-stage trials, and neither includes a once-daily arm.

NCT06126965 — phase 3, 740 participants, primary completion date May 2024, registry status "unknown" [4]. Arms: 0.5% twice daily, and placebo. That is it.

NCT06622824 — phase 2/3, 756 participants estimated, listed as not yet recruiting with completion in October 2027 [5]. Arms: 0.5% twice daily, 1.0% twice daily, matching vehicle. Again, no once-daily arm.

This is an inference rather than a result, but it is a reasonable one. A sponsor that ran three phase 2 trials with once-daily arms and then dropped once-daily entirely from both phase 3 designs has seen something in that phase 2 data. Companies do not spend phase 3 budget on a schedule they believe is competitive and then quietly discontinue it. The dose-ranging work answered the question internally, and the answer was twice daily.

That is the honest summary of what can be inferred: twice daily almost certainly outperformed once daily at equal total dose, because the development programme behaved as though it did. What cannot be said is by how much, in whom, or whether the difference was large enough to matter clinically. Those are precisely the numbers that would be in the unposted results.

Note also what the phase 3 programme compares. NCT06622824 tests 0.5% twice daily against 1.0% twice daily [5] — a concentration comparison, not a schedule one. If you see coverage citing a phase 3 result as evidence that twice-daily beats once-daily, check the arms. That trial cannot answer the question; it has no once-daily arm to compare against.

Why the registry and the press coverage disagree

If you search for pyrilutamide results you will find confident numbers: a 666-patient phase 3 that met its primary endpoint, a gain of roughly 10.65 hairs per square centimetre over placebo at 1.0% twice daily, an announcement in early 2026. You will also find older coverage saying the US phase 2 missed its primary endpoint, alongside company statements calling 0.5% twice daily the optimal dose.

I could not reconcile that coverage with the registry, and I want to be careful about what that does and does not mean.

The registry shows NCT06622824 as not yet recruiting, with an estimated completion in October 2027 and an enrolment target of 756 [5]. The 740-participant phase 3, NCT06126965, carries a primary completion date of May 2024 and a status of "unknown," which is what the registry displays when a sponsor has not updated a record past its expected completion [4]. Neither record reflects a reported result.

There are innocent explanations. Registry records go stale; sponsors update them late or not at all; a trial conducted and announced in China may be registered on a Chinese registry rather than ClinicalTrials.gov; press coverage may be describing a trial I have not found. Results-posting rules also have real carve-outs — the FDAAA requirements that force posting apply to a defined set of trials, and early-phase work on an unapproved drug does not always fall inside them. None of this is evidence of wrongdoing.

What it does mean is practical: the public record does not currently support the specific numbers in circulation. When a figure like "10.65 hairs/cm² over placebo" is repeated across articles with no posted dataset behind it, every one of those articles is sourcing the same press release. That is a single point of failure dressed up as a consensus, and it is worth knowing before you make a decision on it.

What this means if you are tracking pyrilutamide

The mechanism is genuinely interesting and worth following. Pyrilutamide is a topical androgen receptor antagonist — it blocks the receptor at the follicle rather than suppressing DHT systemically the way finasteride and dutasteride do. The appeal is obvious: the same androgen pathway addressed locally, with the aim of avoiding the systemic side effects that cause some men to stop oral treatment. Phase 1 work established the topical safety and pharmacokinetic profile in men with androgenetic alopecia across single and multiple ascending doses [6][7].

There is a reason the twice-daily answer makes pharmacological sense, too. A receptor antagonist works by occupying the receptor, and occupancy decays as the drug clears. A 5-alpha reductase inhibitor like finasteride suppresses an enzyme and the effect persists well beyond the drug's own half-life, which is why once-daily oral dosing works for it. An antagonist applied topically has no such buffer — when local concentration falls, the receptor is available again. Splitting the same daily dose into two applications holds occupancy steadier across twenty-four hours. If the phase 2 data showed twice daily winning at equal total dose, that is the mechanism you would expect to be behind it.

It also explains why the comparison is interesting rather than trivial. For a lot of topicals, twice daily is just more drug and more adherence burden. Here the trials held the daily dose constant, which turns it into a real question about pharmacodynamics rather than a question about dose.

But the practical position today is simple. Pyrilutamide is not approved anywhere and you cannot get it. The question of once versus twice daily is a question about a drug that is not available, and if it does reach market the label will say twice daily, because that is the only schedule in phase 3. The dosing debate is, for now, academic.

If you are reading about this drug because the treatments you can get are not working or not tolerable, that is the more useful problem to solve. The options with actual published evidence behind them are the ones already on the shelf — and we have written about several head-to-heads among them: topical dutasteride versus topical finasteride, PP405 against minoxidil, and oral low-dose minoxidil versus the topical route.

A prescribing clinician is the step that actually changes the outcome here, because the useful moves — switching route, adding a second mechanism, changing concentration, managing a side effect rather than quitting over it — all need one. You can compare hair loss providers on what they will actually prescribe, which varies more than their marketing suggests. Hims and Roman are the broadest on standard topicals and orals. Strut Health and MangoRx handle compounded topical combinations, which is the route worth asking about if single agents have stalled. PeterMD and Maximus sit closer to the hormone-monitoring end, which matters if you are on finasteride and want bloodwork alongside it. Our hair restoration hub covers how the mechanisms stack.

How to read dosing claims about any pre-approval drug

The pyrilutamide situation is a good template, because the same pattern recurs with every compound that gets ahead of its evidence.

Check whether the comparison you are reading about was actually run. A schedule claim needs a trial with both schedules in it. Two trials run years apart at different doses in different populations cannot be subtracted from each other, however tempting the arithmetic looks.

Check whether results exist in a form you can inspect. A press release is a claim about data. A registry results posting or a peer-reviewed paper is data. The gap between those two things is where most of the confident hair loss content on the internet lives.

Watch what the sponsor does, not only what it says. Dropping an arm from phase 3 is a more honest signal than any press release, because it costs money. In this case it is the strongest available evidence on the dosing question, and it points clearly at twice daily.

Learn to read a registry record. It takes about two minutes and it is the single highest-leverage habit for anyone following drugs that are not yet approved. The arms tell you what was actually compared. The enrolment figure tells you whether the trial could detect what it claims. The primary outcome tells you what the trial was designed to show, as opposed to what got reported afterwards. The status field tells you whether the sponsor is still updating the record — "unknown" means the expected completion date has passed without an update [4]. And the presence or absence of a results section tells you whether anybody outside the company has seen the data. All of it is free and none of it requires expertise.

Separate "it works" from "it is better than what I already have." Even a successful pyrilutamide would need to beat, or usefully combine with, drugs that are cheap and available now. No trial has compared it with finasteride, dutasteride or minoxidil. Approval is not a ranking.

Frequently asked questions

Is twice-daily pyrilutamide better than once daily?

Probably, but the evidence is indirect. Three phase 2 trials included both schedules [1][2][3] and none has posted results. Both phase 3 trials dropped once-daily entirely and test only twice-daily dosing [4][5], which is a strong signal that the phase 2 data favoured twice daily. That is an inference from the development programme's behaviour, not a published comparison.

Can I buy pyrilutamide?

No. It is investigational, not approved in any market, and the most recent registered trial lists completion in October 2027 [5]. Anything sold online as pyrilutamide is outside a regulated supply chain, and since no results have been published, there is no established dose, schedule or safety profile for the self-administered use that implies.

Why does published coverage quote specific hair-count numbers?

Those figures come from company announcements rather than posted trial results or peer-reviewed publications. The ClinicalTrials.gov records for all seven registered KX-826 trials have no results section [1][2][3][4][5][6][7]. That does not make the numbers wrong — it means they cannot currently be checked, and that multiple articles quoting them are all citing one source.

How does pyrilutamide differ from finasteride?

Finasteride inhibits 5-alpha reductase systemically, lowering DHT throughout the body. Pyrilutamide is a topical androgen receptor antagonist, intended to block the receptor at the follicle without the systemic DHT suppression. The hoped-for advantage is a better side-effect profile; whether it delivers one, and at what cost in efficacy, is unpublished.

What is non-vellus target area hair count?

The number of terminal — not fine, downy vellus — hairs in a marked square centimetre of scalp, typically ranging from 0 to 300 [5]. It is the standard objective endpoint for androgenetic alopecia trials, measured at baseline and again at 24 weeks, and it is considerably more reliable than before-and-after photography or patient self-assessment.

Sources

• [1] NCT05218642 — KX-826 efficacy, safety and tolerability in male subjects with androgenetic alopecia (US, phase 2, n=123)
• [2] NCT05940506 — Phase II study evaluating the efficacy and safety of KX-826 (n=120)
• [3] NCT06409650 — KX-826 in Chinese female subjects with androgenetic alopecia (phase 2, n=160)
• [4] NCT06126965 — Phase III study of KX-826 in adult male patients with AGA (n=740)
• [5] NCT06622824 — Topical KX-826 solution in Chinese male patients with androgenetic alopecia (phase 2/3, n=756 estimated)
• [6] NCT04502901 — Safety, tolerability and PK of KX-826 following topical multiple ascending dose administration (phase 1)
• [7] NCT04984707 — Safety, tolerability and pharmacokinetics of KX-826 following topical single ascending dose administration (phase 1)