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Every lash serum ingredient that matters

Marketing pages describe benefits. INCI lists describe mechanisms. This is the translation layer — what each ingredient does, and which ones carry a real risk profile around the eye.

Updated September 8, 2026Reviewed by our formulation desk
Ingredient (INCI)ClassFlagWhat it actually does
Myristoyl Pentapeptide-17PeptideGreenSupports keratin production in the lash shaft. The single most studied peptide in lash cosmetics and the backbone of our top-ranked serum. No reported ocular pigmentation risk.
Myristoyl Hexapeptide-16PeptideGreenWorks alongside Pentapeptide-17 to support follicle anchoring, which reduces premature shedding. Usually seen paired rather than alone.
Biotinoyl Tripeptide-1PeptideGreenBiotin bound to a peptide carrier for better delivery. Improves resilience and reduces breakage; common in gentler formulas.
Isopropyl CloprostenateProstaglandin analogCautionExtends the anagen growth phase directly, which is why it works fast. Associated in published literature with conjunctival redness, periorbital skin darkening, and in some long-term users iris pigmentation change and orbital fat atrophy.
Ethylcloprostenolamide
and the longer Dechloro Dihydroxy Difluoro variant		Prostaglandin familyCautionThe active in RevitaLash Advanced, labelled there openly as “a prostaglandin analogue”. Some competitor labels carry the longer dechloro dihydroxy difluoro ethylcloprostenolamide instead — a different molecule, the same family, the same cautions as isopropyl cloprostenate.
BimatoprostPrescription drugRx onlyThe active in Latisse®, the only FDA-approved treatment for eyelash hypotrichosis. Should never appear in a product sold as a cosmetic.
Ethyl TafluprostamideProstaglandin analogCautionA synthetic prostaglandin analog (CAS 1185851-52-8), used in cosmetics at roughly 0.012–0.02%. It is the active in several “next generation” lash serums, including our top-ranked product, and the name is easy to miss because it ends in -prostamide rather than -prostenate. Treat it with the same cautions as isopropyl cloprostenate: the CIR has assessed the two together and had not issued a final safety conclusion as of its 2023 draft. Reported effects in a 28-day use study were minor allergic reactions in 4 of 19 subjects.
PropanediolSolvent / humectantGreenPlant-derived glycol that carries actives and gives the formula a light, non-tacky texture. Very well tolerated around the eye.
Gluconolactone & Sodium BenzoatePreservative systemGreenA gentle preservative pair common in eye-area cosmetics. Their presence is normal and not a red flag; gluconolactone also acts as a mild humectant.
Lactic Acid / Citric AcidpH adjusterGreenPresent at trace level to hold the formula at a skin-compatible pH, not as an exfoliating active.
Panthenol (Pro-Vitamin B5)ConditioningGreenHumectant that keeps the lash shaft flexible and less prone to snapping. Supportive, not a growth active.
Sodium HyaluronateConditioningGreenHydrates the lash line and offsets the drying effect of stronger actives. Very well tolerated.
Panax Ginseng Root ExtractBotanicalGreenTraditional circulation-support botanical, common in premium conditioners. Evidence is supportive rather than conclusive.
Swertia Japonica ExtractBotanicalGreenStudied for follicle-environment support in hair cosmetics. Gentle and long-established in lash formulas.
ArginineAmino acidGreenSupports the amino-acid pool the lash shaft is built from. Frequently paired with peptide systems.
CaffeineBotanicalGreenIncluded for local circulation support. Mild, no known ocular risk at cosmetic levels.
Castor Oil (Ricinus Communis)OilNeutralPopular home remedy. Conditions and adds gloss, and can make lashes look fuller — but there is no good evidence it increases growth. Avoid with extensions: it degrades adhesive.
PhenoxyethanolPreservativeNeutralStandard cosmetic preservative, well tolerated at regulated levels. Its presence is normal and not a red flag.
The 10-second label checkScan the INCI list for any long chemical name containing -prost- — -prostenate, -prostenolamide, -prostamide (as in ethyl tafluprostamide) or -prost on its own. If one is there, the product is a prostaglandin-analog serum regardless of what the front of the box says, and the side-effect section of our safety guide applies to you.

Where our top pick sits

See the ranking
What reading every label actually showedWe pulled the complete INCI list for all six serums directly from each brand’s own product page on 8 September 2026. Five of the six contain a prostaglandin analog. Only The Ordinary’s Multi-Peptide Lash and Brow Serum does not — which is why we raised its score after the check. That includes our own top pick: Qualash contains Ethyl Tafluprostamide. If a brand’s marketing feels clean and botanical, that tells you nothing; only the ingredient list does. See the ingredient reference →
01
QUALASH Advanced eyelash growth serum, 3.5 ml bottle with precision liner applicator
Editor's Choice 2026

QUALASH® Advanced Eyelash Growth Serum

Qualash · 3.5 ml (0.12 fl oz) · ~3 months

Every serum in this ranking except one contains a prostaglandin analog, so the real question is not whether a formula uses one but how honestly it is built around it. Qualash is the best answer we found. Its two lead ingredients are Myristoyl Pentapeptide-17 and Myristoyl Hexapeptide-16 — they sit second and third in the INCI list, ahead of everything else — with arginine and a soy, wheat-germ and Scutellaria baicalensis complex behind them. The prostaglandin, Ethyl Tafluprostamide, appears low in the list, below the preservative system. Compare that with GrandeLASH-MD or Babe Lash, where the analog is the formula’s reason for existing and the rest is amino acids and humectants. Qualash also publishes the complete INCI list on its own product page, states a dated 25-day first-change window instead of a seven-day fantasy, ships the most controlled applicator in the group, and guarantees a full 90 days — long enough to actually finish a treatment cycle before deciding.

Contains Ethyl TafluprostamideFull INCI publishedPeptide-led INCI order90-day guaranteeVegan · EU-manufacturedPrecision liner applicator
What we liked
  • Peptides lead the INCI list; the prostaglandin sits low, below the preservatives
  • Publishes the complete INCI on its own product page — most rivals publish a curated summary
  • Realistic, dated claims (25 days first change, 12-week full cycle)
  • 90-day money-back guarantee covers a whole treatment cycle
  • Precision felt-tip liner applicator — the best placement control in the group
What to weigh
  • Contains a prostaglandin analog, so every class caution applies in full
  • Not for anyone avoiding prostaglandins, or with glaucoma or ocular hypertension
  • Sold direct rather than through US department stores

Growth active: Ethyl Tafluprostamide

Full INCI, verified 8 September 2026 from the qualash.com product page

Aqua, Myristoyl Pentapeptide-17, Myristoyl Hexapeptide-16, Propanediol, Arginine, Lactic Acid, Glycine Soja Germ Extract, Triticum Vulgare Germ Extract, Scutellaria Baicalensis Root Extract, Sodium Benzoate, Gluconolactone, Calcium Gluconate, Sodium Chloride, Alcohol, Phenoxyethanol, Ethyl Tafluprostamide, Citric Acid, Triethanolamine.

Verdict: The best-executed product in a category where almost everything uses the same mechanism: peptide-led formulation, the analog kept low and disclosed, honest timelines and a guarantee long enough to matter. If you want to avoid prostaglandin analogs altogether, skip to #6.

9.5/10
EfficacySafetyValueApplicator
≈ $42 / 3.5 ml
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