Kerastase Genesis vs Tara: Breakage, or Thinning?

Kérastase Genesis is the benchmark ‘anti-hair-fall’ serum. But its headline number answers a narrower question than it looks — and reading it properly tells you whether Genesis, or something else, is what your hair needs.

What the 84% actually measures

Genesis’s famous claim is ‘up to 84% less hair fall’ — but read the small print: due to breakage. That means fewer hairs snapping mid-length from fragility, an in-house figure with no published study attached. It is a fiber-strength result, not regrowth and not treating thinning at the follicle. A real benefit — for a different problem.

Credit where it’s due: they state a dose

Unlike most serums, Genesis names its anchor molecule at a concentration: Aminexil 1.5%. We respect that — a stated dose is exactly what we ask every brand for. Aminexil helps anchor hair and reduce breakage-related fall; it is not a regrowth drug, and Genesis doesn’t claim it is.

Side by side

Kérastase Genesis Tara Follicle-Stimulating
Hero active Aminexil 1.5% (stated) + caffeine. Capixyl (red-clover peptide) + onion for microcirculation.
States a working dose? Yes — Aminexil 1.5%. Credit where it’s due. No published % — but claims are held to the dose-gate, and the evidence standard is public.
What ‘hair fall’ means here Less breakage — the headline 84% is hair snapping from fragility, not regrowth. Follicle stimulation and density support — a different mechanism.
Evidence An in-house 84% figure; no published citation or method. A public, Scopus-counted evidence table — each claim has a study.
Says what it does NOT do? ‘Less breakage’ is rarely spelled out as ‘not regrowth’. Yes — onion isn’t the 87% myth; a peptide needs its dose.
Positioning Premium salon (~£52 / 90 ml). Accessible, evidence-first.

So which one?

If your hair is snapping mid-length — breakage — Genesis’s fiber-strength story fits, and it tells you its dose. If your concern is thinning or density at the root, that is a different active set, and the honest questions are the same for everyone: what is the dose, and where is the study? Our onion, for the record, isn’t the 87% myth either.

See the Follicle-Stimulating Scalp Serum, the evidence table, or the The Ordinary comparison.

Related

which hair ingredients actually work · rosemary vs minoxidil · UAE hair-loss data.

Competitor facts from Kérastase Genesis retailer pages (Lookfantastic) + INCIDecoder, accessed June 2026. The 84% figure is a brand in-house claim with no published citation found. Tara actives per the product label.