Why you are losing your hair: DHT, the androgen receptor, and what actually stops it
Not stress, not your shampoo, not the hard water - in the overwhelming majority of men, one androgen acting on follicles that...
Folliva Labs
CB-03-01 2.5/5% (Clascoterone)
- Blocks DHT at the receptor, on the scalp
- Your skin breaks it down where it lands
- Every batch tested by an independent lab before it ships
- Phase 3 trials completed in the US and Europe
Concentration
Volume
Batch and date on every bottle
Discreet, tracked shipping
Formulated & tested in the EU
Support before you order
How it differs from RU-58841 and pyrilutamide
All three occupy the same receptor. RU-58841 and pyrilutamide are non-steroidal molecules designed from scratch to fit the lock; clascoterone is a steroid that already resembles the hormone. The difference that actually matters to you is evidence: this is the only one of the three taken through Phase 3 trials in the US and Europe. Run one blocker at a time — never two.
What to expect, honestly
In the trials, hair counts pulled away from placebo over months, not weeks, and the twelve-month results were better than the six-month ones. Some early shedding as follicles reset is common and reads like failure. Photograph the same spot in the same light every month and judge it at six.
Suitability & safety
For research use only. Not a medicine. In the hair trials, local skin reactions were similar to the placebo liquid; in the acne studies a small number of people showed temporary suppression of the adrenal axis, which resolved within four weeks of stopping, and no cortisol data from the hair trials has been published. Patch-test first, use one blocker at a time, and speak to a professional if you are unsure.
Batch & storage
Every bottle is stamped with its batch number, blend date and expiry. Store it cool, dry and out of direct light — heat and daylight are what degrade it, not the calendar alone.
SPECIFICATION
Concentration2.5% / 5% w/v
Volume50 ml
HOW IT WORKS
The same lock. A key shaped like the hormone itself.
Pattern hair loss is one hormone giving your follicles the same instruction, cycle after cycle. CB-03-01 is built to look enough like that hormone to take its seat — and then to be taken apart by your own skin once it has.
- 01
DHT reaches the follicle
Testosterone converts into DHT. In a susceptible scalp it binds androgen receptors inside the follicle and tells it to shrink. The receptor is the lock. DHT is the key.
- 02
The follicle miniaturises
Each cycle that signal lands, the growth phase gets shorter and the hair comes back finer. This runs quietly for years before a mirror admits it.
- 03
Clascoterone takes the seat first
It is a steroid, shaped closely enough to DHT to compete for the same receptor pocket — and it holds that pocket without switching the receptor on. No signal, no instruction to shrink.
- 04
Then your skin takes it apart
Enzymes in the skin cut it into cortexolone, a substance your body already makes. That is the design: act where you spray it, then stop being clascoterone.
Why this one, out of three blockers
Same target, three ways to reach it. The honest reason to choose CB-03-01 is evidence: it is the only one taken through large Phase 3 trials in the US and Europe, and the only one whose molecule is already approved for use on human skin in another form. That does not automatically make it stronger than RU-58841. It makes it the best documented.
One blocker at a time
RU-58841, pyrilutamide and CB-03-01 all compete for the same receptor. Running two does not double the effect — it doubles what can irritate your scalp and leaves you unable to tell which one did anything. Pick one, give it six months, judge it on photographs.
What the trials actually showed
Two Phase 3 studies, 1,465 men, 51 centres across the US and Europe, a 5% solution twice a day for twelve months. Both beat placebo on hair count at six months — but they disagreed on by how much: one showed a 539% relative improvement, the other 168%. That gap is real and you should know about it before you spend anything. At twelve months the men who stayed on it held roughly 2.4 times the hair count of the men switched to plain vehicle.
What we can be held to
Those trials were run by the company developing the licensed version, on their formulation — not on ours. Filing is expected in 2027 and approval no earlier than late 2027, so nobody sells an approved hair-loss version of this today, us included. What we can be held to is the bottle: the compound, blended at 2.5% or 5% by us in the EU, tested by an independent laboratory batch by batch, and dated so you know how old yours is.
THE ROUTINE
Twice a day. That is the part people get wrong.
It comes as a spray pump. Morning and night, onto a dry scalp — the trials that produced those numbers dosed twice a day, and half of that is not half the result.
-
01
Count the pumps
Six to seven pumps is roughly 1 ml — one application, and there are two of them a day. A 50 ml bottle is about three and a half weeks at the full dose.
-
02
Spray the skin, not the hair
Part the hair and spray onto the scalp over the thinning area. The receptors are in the skin; hair is just what is in the way.
-
03
Let it dry
Spread it gently with a fingertip and let it dry fully before anything else touches it. Nothing to rinse out.
-
04
Morning and night, every day
Skipping the evening application is the quietest way to halve your own dose. Photograph the same spot monthly, in the same light.
Research use only. Batch number, blend date and expiry are printed on the bottle.
WHAT TO EXPECT
Nothing happens for a while. That is normal.
A receptor blocker holds the line before it grows anything back. In the trials the curves separated over months, not weeks — and the twelve-month numbers were better than the six-month ones.
-
WEEKS 0–4
Baseline, and possibly a shed
Take your photographs before the first application — you cannot go back for them later. Some shedding as follicles reset is common and reads like failure. It usually is not.
-
MONTHS 1–2
Loss slows before anything grows
Less in the drain and on the pillow, nothing new on your head yet. This is where most people quit, about four months before they would have found out.
-
MONTHS 3–6
First measurable growth
This is where the trial hair counts pulled clearly away from placebo. On your own head it looks like fine, pale hairs at the temples — easy to miss without the baseline photo.
-
MONTHS 6–12
An honest verdict, then the reason to continue
Six months is the earliest fair judgement. In the trials the second six months added more than the first, and the men who came off it gave the ground back.
MECHANISM COMPARISON
The options, side by side.
The common ways men treat male-pattern hair loss, compared on mechanism, side effects, evidence and cost.
| Feature | RU-58841Topical antiandrogen | CB-03-01Clascoterone, topical antiandrogen | PyrilutamideKX-826, topical antiandrogen | MinoxidilTopical growth stimulant | Oral finasterideSystemic DHT blocker | Ketoconazole shampooTopical antifungal | GHK-CuCopper peptide, scalp support | Natural topicalsCaffeine, rosemary, saw palmetto | Doing nothingBaseline |
|---|---|---|---|---|---|---|---|---|---|
| Mechanism | |||||||||
| What it acts on | The androgen receptor | The androgen receptor | The androgen receptor | Potassium channels, blood flow | 5-alpha-reductase. Lowers DHT | Fungus. Mildly, the receptor | The scalp skin itself. Not the hormone | Several weak effects. None well mapped | |
| Where it acts | Scalp | Scalp. Broken down there by design, but measurable amounts still reach the blood | Scalp, by design | Scalp. Some absorption | Whole body | Scalp | Scalp | Scalp | |
| Side effects | |||||||||
| No systemic or sexual side effects | PartlyDesigned to break down before it reaches the blood. No human data proves that it does. | PartlyBuilt to break down in the skin, but blood levels measured for their scalp solution are similar to the acne cream's, so a smaller treated area is not a safety argument. In the acne studies 3 of 42 had brief adrenal suppression that cleared after stopping. | PartlyBuilt to act locally. In the trials, safety was no different from placebo. The data is still thin. | YesNot a hormonal drug. Rare heart-rate effects at high doses. | NoLower libido and erectile problems in a minority of men. Most recover after stopping. Some report that they did not. | YesTopical, barely absorbed | YesA topical peptide. It does nothing to hormones, for better or worse. | YesNothing here reaches your bloodstream in any amount that matters | Yes |
| No scalp irritation | PartlyThe alcohol carrier can dry or sting. That is the vehicle, not the compound. | PartlyIn the hair trials local reactions matched the placebo liquid, but the placebo was the same carrier without the drug. The carrier is glycol-heavy and can dry the skin. | PartlyUsually mild, but it does not suit everyone | NoItching and flaking are common. Mostly the propylene glycol. | YesIt never touches your scalp | PartlyCan dry the scalp with regular use | YesGenerally well tolerated on skin. Patch-test anyway. | YesIn the rosemary trial, less itching than minoxidil. | Yes |
| What it does | |||||||||
| Blocks DHT | YesAt the receptor. A non-steroidal molecule. | YesAt the receptor. Same target, a steroidal molecule. | YesAt the receptor. Same target, non-steroidal like RU-58841. | NoIt grows hair by a different route entirely | YesLowers DHT at the source | PartlyA weak antiandrogen at best | NoNot an antiandrogen. It does nothing to DHT. | PartlySaw palmetto is a weak 5-alpha-reductase inhibitor | No |
| An antiandrogen you apply, not swallow | Yes | Yes | Yes | NoTopical, but not an antiandrogen | NoAn antiandrogen, but a tablet | PartlyTopical, weakly antiandrogenic | NoTopical, but not an antiandrogen at all | PartlyTopical. Weakly, and only through saw palmetto. | |
| Stimulates new growth on its own | NoIt takes the brake off. It adds nothing. | NoIt takes the brake off. It adds nothing of its own. | NoSame route. It removes suppression. | YesThis is the one thing it is for | NoSame idea: it removes suppression | No | NoIt looks after the scalp. It does not push growth. | PartlyA little, in small trials. Nothing like minoxidil. | |
| Also works on the scalp itself | No | No | No | No | No | YesClears the flaking and inflammation. The only antifungal here. | YesThis is the whole job of it: the condition of the skin your follicles grow from | PartlySome anti-inflammatory effect. It is not an antifungal. | |
| Evidence and approval | |||||||||
| An approved medicine for hair loss | NoA research compound. No approved human use, anywhere. | NoThe same molecule has been an approved 1% acne cream in the US since 2020, but nothing containing it is approved for hair loss anywhere. Another company is expected to file in 2027. | NoA research compound. No approved use, anywhere. The manufacturer is heading for a filing in China. | YesApproved for male-pattern hair loss | YesApproved, on prescription | PartlyApproved as an antifungal, not for hair loss | NoA peptide sold in cosmetics. No medicine containing it is approved anywhere. | NoCosmetics. Nobody has taken them through approval. | |
| Human evidence behind it | NoNo completed human trials. None. | YesTwo Phase 3 studies, 1,465 men, twelve months. Run by the company taking it through approval, on their formulation, not ours. | PartlyPhase 3 trial data at 0.5% and 1.0%, which puts it ahead of most topicals. The results are the manufacturer's and are not yet published. | YesDecades of randomised trials | YesDecades of randomised trials, and the longest evidence base of anything on this table | PartlyA handful of small studies | PartlyReal human data, but in skin and wound healing. What exists for hair is thin. | PartlyOne small trial matched rosemary oil to 2% minoxidil. Caffeine has a few. That is all of it. | |
| Available without a prescription | YesOnly because there is no approved use to prescribe | YesNo approved hair-loss version to prescribe. The acne cream made from the same molecule is prescription only. | YesSame reason again. There is no approved version to prescribe, anywhere. | YesOver the counter | NoPrescription only. A doctor has to agree. | Partly1% over the counter. 2% is usually a prescription. | YesNo approved medicine here to prescribe | YesAny shop, any time | |
| Living with it | |||||||||
| If you stop | Loss resumes | Loss resumes | Loss resumes | Shedding within weeks | Loss resumes | The flaking comes back | The scalp goes back to how it was | Back to baseline | |
| Daily effort | Once a day | Twice a day | Once a day | Once or twice a day | One tablet | Two or three times a week | Once a day | Daily, or every wash | None |
| Cost per month, roughly | €40–50 | €145 at 2.5%, €230 at 5% | €60–90 | €20–60 | €10–20 | €5–10 | €90 | €10–25 | €0 |
A comparison of mechanisms, not medical advice. Minoxidil and finasteride are approved medicines with decades of randomised trials behind them, and finasteride has the longest evidence base of anything here. RU-58841, CB-03-01 and pyrilutamide are research compounds: none of them is an approved hair-loss medicine today. The Phase 3 figures quoted for clascoterone come from the formulation another company is taking through approval, not from ours, and no cortisol data from those hair trials has been published. The pyrilutamide trial results come from the manufacturer and are not yet published. GHK-Cu is a copper peptide included here as scalp support, not as a regrowth treatment. The natural column covers topical caffeine, rosemary oil and saw palmetto, where the human data is real but thin. Prices are rough monthly estimates and vary by dose, bottle size and brand, and each assumes the routine on that product's own page. Speak to a doctor before you start or stop anything.
What else the lab makes.
RU58841 Topical Solution
4.9 (88)·5/8% · 30/50/100 ml
Occupies the androgen receptor so DHT cannot deliver its signal to the follicle.
This is the cause, not the symptom. On its own it will not push a dormant follicle back into growth.
From €39,99
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Pyrilutamide 0.5% (KX-826)
4.6 (16)·0.5% w/v · 30 mL
A newer topical androgen-receptor antagonist. Different molecule, same target as RU-58841.
For people who do not tolerate RU. Run one blocker or the other, not both.
€90,00
Waitlist
CB-03-01 2.5/5% (Clascoterone)
2.5/5% · 50 ml
Blocks the androgen receptor at the follicle, then breaks down in the skin into an inactive form.
The only one here that finished phase 3. Clascoterone sold much cheaper elsewhere is usually weaker than the label says.
From €129,00
Waitlist
Minoxidil 5%
4.6 (25)·5% · 60 mL
Extends the growth phase so follicles stay active longer. It does nothing to the hormone driving the loss.
Pairs with a blocker, never replaces one. Stop it and the growth it borrowed goes back.
€60,00
Waitlist
Ketoconazole Shampoo
An antifungal wash that handles the flaking and irritation sitting underneath a lot of shedding.
Two or three washes a week, alongside a blocker. It is not a blocker itself.
€29,99
Waitlist
GHK-CU Copper Peptide Spray
4.5 (13)·Copper peptide · 30 mL
A copper peptide that works on the condition of the scalp itself. Not an antiandrogen; it does nothing to DHT.
For scalp quality. On its own it will not hold a receding hairline.
€50,00
Waitlist
Natural Hair Regrowth Serum
4.6 (13)·Topical · 50 mL
Caffeine, rosemary and botanical oils. Scalp support, and the mildest thing in the range.
A leg of the routine, not the whole table. It does not block DHT.
€60,00
Waitlist
FAQ
Questions, answered.
What is CB-03-01?
CB-03-01 is the development code for clascoterone, a topical androgen blocker. The same molecule was approved in 2020 as a 1% acne cream — Winlevi, the first topical androgen-receptor blocker the FDA has approved — and a 5% scalp solution has completed Phase 3 trials for male-pattern hair loss under the name Breezula.
Is this Breezula?
No. Breezula is the licensed product being taken through approval by the company that developed it, and it is not approved or on sale anywhere yet. What we sell is the same compound, blended by us in the EU into a labelled solution, for research use. We are not them and we do not claim their trial as our own.
How is it different from RU-58841 and pyrilutamide?
All three sit in the same androgen receptor and stop DHT delivering its instruction. RU-58841 and pyrilutamide are non-steroidal molecules designed to fit that lock; clascoterone is a steroid that already resembles the hormone. The practical difference is the evidence behind them — this is the only one of the three taken through Phase 3 trials in the US and Europe. Use one blocker at a time, never two.
2.5% or 5%?
5% is the strength that went into the Phase 3 trials, twice daily, and it is the one with the published numbers attached. 2.5% was tested earlier and did less. Take 2.5% if you want to start gently or see how your scalp handles it; take 5% if you want the strength the evidence is actually about.
How do I use it, and how long does a bottle last?
Six to seven pumps is roughly 1 ml — one application — onto a dry scalp, twice a day. That is about 2 ml a day, so a 50 ml bottle covers roughly three and a half weeks. It is a spray pump, so you count it; there is nothing to measure.
Does it get into my bloodstream?
It is designed not to. Enzymes in the skin cut clascoterone into cortexolone, something your body already produces. It is not zero: the amount circulating from the scalp solution measured similar to the approved acne cream, and in the acne studies a small number of people showed temporary suppression of the adrenal axis, which returned to normal within four weeks of stopping. No cortisol data from the hair trials has been published.
Are there side effects?
In the hair-loss trials, local skin reactions were similar to those from the placebo liquid, and no serious adverse events were reported. That is a good record, not a guarantee about you. Patch-test on a small area first and stop if you react.
Why does it cost more than RU-58841?
Because of how much of it is in the bottle. At 5%, a 50 ml bottle holds 2.5 grams of clascoterone, and the raw compound costs several times what RU-58841 does — the price is mostly the material, not the label. For reference, the licensed version is expected to arrive around 2028 at roughly $110 a month, on prescription.
How do I know it is genuine?
An independent laboratory tests every batch before it ships, and each bottle carries its batch number, blend date and expiry. Testing our own product and marking our own homework is worth very little; the point of an outside lab is that it can say no.
Shipping and returns?
Shipped from inside the EU, usually 2–5 working days, in plain unbranded packaging. Unopened bottles can be returned within 14 days.
Science articles
Read before you start.
What the research actually says about hair loss, DHT, and the compounds people reach for.
