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PeptideAI
Observationalhair

Capixyl

A hair complex pairing a matrix-strengthening tetrapeptide with a red clover isoflavone that inhibits 5-alpha-reductase, attacking both the follicle's anchoring and its DHT exposure.

Also known as Acetyl Tetrapeptide-3 + Trifolium pratense extract, acetyl tetrapeptide-3 / biochanin A complex, red clover hair complex, Capixyl

Observational — Human data without randomisation. Suggestive, and easily confounded.

The 46% anagen-to-telogen figure is manufacturer data from a small uncontrolled panel. A separate randomised triple-blind 24-week study of a multi-ingredient herbal formulation containing biochanin A and acetyl tetrapeptide-3 reported efficacy broadly comparable to 3% minoxidil — encouraging, but that formulation contained several other actives, so it is not a clean test of Capixyl.

How it works

Androgenetic alopecia has two components you can attack topically: the androgen signal that miniaturises the follicle, and the extracellular matrix that holds it in place and supports its dermal papilla. Biochanin A, the principal isoflavone in red clover, inhibits both type I and type II 5-alpha-reductase, lowering local conversion of testosterone to DHT and reducing downstream inflammatory signalling in the follicle. Acetyl tetrapeptide-3 is a matrikine-type peptide that increases collagen and laminin around the hair bulb, improving follicle anchoring. The manufacturer's headline figure is an increase in the anagen-to-telogen ratio of up to 46% — that is a cycle ratio, not a 46% increase in hair count, and it is routinely misquoted as the latter.

Targets: 5-alpha-reductase types I and II, Dihydrotestosterone production, Extracellular matrix around the hair bulb, Collagen and laminin synthesis

Dosing

ProtocolDoseFrequencyRoute
Leave-on scalp serum or shampooLeave-on beats rinse-off by a wide margin; a shampoo has a contact time of about ninety seconds.—once or twice daily for leave-on, or every wash for a shampootopical
  • · Supplier recommendation is 3-5% of the finished formula for leave-on products. Sold as a liquid complex, not a lyophilised peptide.

Cycling

Continuous use; androgenetic alopecia is a maintenance problem and gains reverse within months of stopping.

Work out your exact syringe units →

Pharmacology

Half-life
Not applicable — a formulated complex rather than a single molecule.
Onset
Anagen-to-telogen shifts take 3-4 months; visible density change takes 6 months.
Routes
topical
Molecule
Blend of a synthetic acetylated tetrapeptide and a plant isoflavone

Handling

Diluent
Supplied as a ready-to-use liquid complex
Lyophilised
Not applicable.
Reconstituted
Cool, dark storage in the supplier bottle; finished products should be preserved.
Light sensitive
Yes — keep it out of the light

Mixing

Not sold as a powder for reconstitution.

Side effects

  • uncommonScalp irritation— Reported as very low in the comparative trial work.

Do not use if

  • Hormone-sensitive conditions where phytoestrogen exposure is unwanted — biochanin A is a weak phytoestrogen, and although topical scalp exposure is small, it is not zero.

Combining it

  • redundantfinasteride — Both work on 5-alpha-reductase; oral finasteride does it systemically and far more completely.
  • synergyminoxidil — Anti-androgen plus vasodilator is the standard combination logic in topical hair therapy.
  • synergybiotinoyl-tripeptide-1 — Frequently co-formulated in the same scalp serums.

What to monitor

  • · Fixed-area hair counts and standardised photographs at 0, 3 and 6 months.
  • · Wash counts to track shedding independently of density.

Legal status

Cosmetic ingredient blend approved worldwide under its component INCI names.

References

  • Lucas Meyer Cosmetics Capixyl technical dossier (other)

Mechanism in depth

Androgenetic alopecia has two topically addressable components and this product picks one from each, which is a sensible piece of design. The androgen arm: testosterone is converted to dihydrotestosterone by 5-alpha-reductase, DHT binds the androgen receptor in genetically susceptible dermal papilla cells, and the follicle progressively miniaturises across successive cycles — shorter anagen, smaller bulb, thinner shaft — until it produces vellus hair. Type II 5-alpha-reductase is the isoform finasteride targets and is concentrated in the follicle. Biochanin A, the principal isoflavone of red clover, inhibits both type I and type II 5-alpha-reductase; Evans and colleagues demonstrated isoflavonoid inhibition of 5-alpha-reductase in genital skin fibroblasts and prostate tissue back in 1995, and Hiipakka's group later worked out structure-activity relationships for polyphenol inhibition of the human enzymes. That is real, independently published pharmacology, not a supplier claim. The matrix arm: acetyl tetrapeptide-3 is presented as increasing collagen and laminin around the hair bulb, improving the anchoring of the follicle in the dermal sheath. That arm is supplier-characterised. What makes Capixyl unusual for this class is that the clinical study actually exists and is indexed: Loing and colleagues published a randomised, placebo-controlled study of 30 volunteers using TrichoScan measurement over four months. It is manufacturer-authored — Loing was at Lucas Meyer — but it is randomised, placebo-controlled and published, which puts it ahead of most of this category.

What usually goes wrong

The 46% figure is the single most misquoted number in the hair peptide world. It is the change in the anagen-to-telogen ratio, not a 46% increase in hair count. The actual anagen hair increase in the Loing study was 13%. Both numbers are in the same abstract and only one of them gets printed on packaging. Second, the shampoo problem: Capixyl is sold in shampoos and a shampoo has a contact time of roughly ninety seconds before you rinse a 5-alpha-reductase inhibitor down the drain. Leave-on beats rinse-off by a very wide margin and it is not close. Third, the phytoestrogen caution is worth keeping in proportion — topical scalp biochanin A is a small exposure, but it is a real oestrogen receptor ligand whose metabolite is a stronger one, it has not been quantified for systemic absorption, and anyone with a hormone-sensitive cancer history should think about it rather than dismiss it. Fourth, stopping. Androgenetic alopecia is a maintenance problem; gains reverse within months of stopping because the underlying androgen signal never went anywhere.

Bloodwork worth running

MarkerWhenWhy it matters
Ferritin, serum zinc, TSH and vitamin DBaseline, before starting.Standard exclusion panel before judging any hair intervention. Iron deficiency and thyroid disease are the two commonest reversible causes of shedding and neither responds to a topical.Act if: Ferritin below 30 ng/mL, or below 50 with active shedding, needs correcting first. Any abnormal TSH needs proper assessment.
DHT and total testosteroneBaseline only, and only in that scenario.Not to monitor the product — topical scalp biochanin A is not expected to move systemic androgens the way oral finasteride does, and there is no evidence that it should. Worth a baseline only if you are also considering or already taking an oral 5-alpha-reductase inhibitor, so you can tell the two apart.Act if: No threshold for the topical. If systemic DHT falls substantially on a topical-only protocol, something else is going on.

Pharmacokinetics

Metabolism
Biochanin A is extensively metabolised — it is demethylated to genistein and both are heavily glucuronidated and sulfated. This matters for the phytoestrogen question, because genistein is a more potent oestrogen receptor beta ligand than biochanin A. The tetrapeptide is degraded by skin peptidases.
Elimination
Systemic exposure from scalp application is expected to be small but is not zero, and has not been measured.

Receptor targets

  • 5-alpha-reductase types I and II (biochanin A) — Isoflavonoid inhibition of 5-alpha-reductase is independently published; no IC50 specific to the Capixyl formulation

    Reduced local conversion of testosterone to DHT in the follicle.

  • Oestrogen receptor beta (biochanin A, off-target) — Biochanin A is a weak phytoestrogen; its metabolite genistein is more potent at ER-beta

    The basis for the hormone-sensitive condition caution. Topical scalp exposure is small but has not been quantified.

  • Perifollicular collagen and laminin (acetyl tetrapeptide-3) — No receptor identified

    Claimed improvement in follicular anchoring in the dermal sheath.

Trials

  • Loing et al. randomised placebo-controlled study of a Trifolium pratense extract plus biomimetic peptide combination for hair loss (J Cosmet Sci) Randomised placebo-controlled · n=30 · 17 weeks · 2013

    Four months of daily topical application in 30 volunteers with receding hair, measured by TrichoScan. Treated group: anagen hair +13%, telogen hair density -29%, anagen/telogen ratio +46% over baseline. Placebo group: anagen -2%, telogen +23%, A/T ratio -33%. Note carefully that the widely quoted 46% is a cycle ratio, not a hair count.

What to expect, and when

Month 3-4: the anagen-to-telogen shift measured in the Loing study, and the point at which shedding should be noticeably reduced. Month 6: visible density change if it is going to happen. Month 12: full effect. Every hair intervention runs on the hair cycle and nothing accelerates it.

Stacking and comparisons

Minoxidil is the sensible partner and the combination follows the standard logic of topical hair therapy: an anti-androgen to slow miniaturisation plus a vasodilator to support the follicles you still have. They act on different mechanisms with no overlap. Biotinoyl tripeptide-1 is frequently co-formulated and adds the anchoring arm. Oral finasteride is where the redundancy question gets interesting: finasteride inhibits type II 5-alpha-reductase systemically and far more completely than any topical isoflavone will locally, so if you are already on it, Capixyl's main arm is largely redundant and you are paying for the peptide. Conversely, if you are specifically avoiding oral finasteride because of sexual side effect concerns, a topical 5-alpha-reductase inhibitor with minimal systemic absorption is a rational thing to want — just calibrate the expected effect size honestly, because it is much smaller.

Against topical or oral minoxidil, minoxidil has far larger and more numerous randomised trials; a separate randomised triple-blind study of a multi-ingredient herbal formulation containing biochanin A and acetyl tetrapeptide-3 reported efficacy broadly comparable to 3% minoxidil, but that formulation contained several other actives so it is not a clean test. Against oral finasteride, finasteride reduces serum DHT by around 70% and has trial data across decades; a topical isoflavone does not approach that. Against the other peptides in this hair group — AHK-Cu, biotinoyl tripeptide-1, zinc thymulin — Capixyl is the only one with a published randomised placebo-controlled human study, which makes it the one to pick if you are picking one.

Rough cost

$15–$60/month. Sold as a liquid complex at roughly $30-60 per 100 mL at a 3-5% use level, so DIY scalp serums are cheap. Finished products $18-60 a month. Market observation, not a sourced pricing study.

Genuinely uncertain

  • The Loing study is manufacturer-authored with 30 participants. It is randomised and placebo-controlled, which is genuine, but it is small and not independent.
  • No IC50 for biochanin A against human follicular 5-alpha-reductase specifically has been published.
  • The acetyl tetrapeptide-3 arm has no independent characterisation; its contribution to the clinical result cannot be separated from the isoflavone's.
  • Systemic absorption of biochanin A from scalp application has never been quantified, so the phytoestrogen caution is reasoning rather than measurement.
  • The residue sequence of acetyl tetrapeptide-3 was not resolved in this session.
  • No molecular weight is given because it is a blend.

Papers