Lash serums fall into two groups, and the ingredient list says which group a product is in before any claim is read. One group contains a prostaglandin analogue, the drug class with trial evidence behind it. The other does not. The Ordinary's Multi-Peptide Lash and Brow Serum is in the second group, and this page reads what it contains instead.
Four peptides, four supplier names
The published list has 30 ingredients. After water, glycerin and butylene glycol, the peptides come first:
| Pos. | Ingredient (INCI) | Brand's named complex | Complex partner on the label | Molecular weight | PubMed records |
|---|---|---|---|---|---|
| 4 | Myristoyl Pentapeptide-17 | SYMPEPTIDE XLASH | — | 796.1 g/mol | 0 |
| 5 | Biotinoyl Tripeptide-1 | Widelash | Panthenol (9) | 566.7 g/mol | 0 |
| 6 | Oligopeptide-2 | Anargy | Glycoproteins (12) | no record | 0 |
| 7 | Acetyl Tetrapeptide-3 | CAPIXYL | Red clover extract (14) | 509.6 g/mol | 1 |
Weights from PubChem; counts from NCBI E-utilities by INCI name in title or abstract, run 2026-09-17; trade names Anargy and Widelash also returned 0 across all fields. Oligopeptide-2 has no PubChem compound record, so its structure cannot be confirmed from a public register.
Three of the four peptides have no indexed literature under their own names. The fourth has one record, a hair-loss trial of a three-active combination against minoxidil with no placebo arm, set out on our acetyl tetrapeptide-3 entry. The lead peptide's missing literature, and the nearest thing to a clinical study of a peptide lash serum — an uncontrolled trial that did not name its peptides — are on our myristoyl pentapeptide-17 entry.
One peptide, two supplier names, two products
Biotinoyl tripeptide-1 appears in two The Ordinary serums under two different supplier names. Here the brand calls it part of the Widelash complex, paired with panthenol. In its Multi-Peptide Serum for Hair Density, the same molecule is part of Procapil, which is declared with apigenin and oleanolic acid. Neither of those partners is in the lash formula.
That matters for reading claims. The six studies indexed under Procapil, described on our biotinoyl tripeptide-1 entry, test the three-ingredient blend. They are not studies of this combination, which does not contain the blend's other two ingredients.
What else is in it
The rest of the formula tracks the hair density serum closely:
- Caffeine at position 8, directly after the four peptides. In the scalp product caffeine sits above both peptides; here all four peptides sit above it.
- REDENSYL, which the brand lists as larch wood extract, green tea leaf extract and zinc chloride (positions 13, 15 and 18), with glycine at 11.
- Red clover flower extract at 14, the CAPIXYL partner for acetyl tetrapeptide-3.
- Panthenol at 9 and arginine at 10.
A US label cannot carry these supplier names, which is why the brand lists them in its description and the components appear separately in the declaration; our guide to reading an ingredient list explains the rule. The brand gives the formula's pH as 7.30 to 7.40, close to neutral.
The ingredient class that is not in the bottle
No prostaglandin analogue appears anywhere in the declaration. That is the most informative fact on the label, because it places the product relative to the only lash-growth evidence with a regulator's approval behind it.
Bimatoprost ophthalmic solution 0.03%, sold as Latisse, carries a US approval for hypotrichosis of the eyelashes. Its FDA label reports the pivotal study directly:
| Latisse pivotal trial, FDA label | Bimatoprost | Vehicle |
|---|---|---|
| Patients randomized | 137 | 141 |
| At least one-grade gain on the Global Eyelash Assessment at week 16 | 107 (78%) | 26 (18%) |
| Mean increase in eyelash fullness at week 16 | 106% | 12% |
The same label states that effects began returning toward baseline within four weeks of stopping, and lists brown iris pigmentation, likely permanent, among its warnings. PubMed held 116 title-or-abstract records for bimatoprost with eyelashes or hypotrichosis on 2026-09-17, 20 of them tagged as randomized controlled trials. The equivalent search for any peptide with eyelashes or eyebrows returned 9.
A 2026 survey of 79 lash-enhancing cosmetics found about 30% contained a prostaglandin analogue that is not regulated for cosmetic use, and described the rest as built on ingredients such as amino acids, panthenol and peptides. That survey is set out on our myristoyl pentapeptide-17 entry. This formula belongs to the second group: it avoids the drug class and its warnings, and it does not have that class's evidence.
What the brand claims, and on what basis
The product page says the serum is designed to support thicker, fuller and healthier-looking lashes and brows, and that visible improvements can typically be seen in as little as four weeks with consistent use. As read on 2026-09-17, the page attaches no study, no participant number and no method to that statement. The brand's face serum in the same range footnotes a 30-person study; this product's page carries no equivalent.
For scale on timing, the drug trial above reported 15% of the bimatoprost group responding at week 4, 50% at week 8 and 78% at week 16. That comparison is about timing only; the two products do not contain the same kind of ingredient.
What the ingredient list does and does not tell you
It establishes four peptides in the top quarter of the list, ahead of caffeine, under four supplier names. It establishes that three of them have no indexed literature under their own names and the fourth has one scalp trial with two other actives. It establishes a near-neutral formula that shares most of its botanicals with the brand's scalp serum, and that contains no prostaglandin analogue.
It does not establish what the serum does to lashes or brows. We have not used it, and the list alone has no way to show a lash-length result. For how peptides fare on hair more generally, see our page on peptides for hair thickness.
Sources
- The Ordinary, Multi-Peptide Lash and Brow Serum — published ingredient list, named complexes, pH and usage statement, theordinary.com, read 2026-09-17.
- LATISSE (bimatoprost ophthalmic solution) 0.03%, Allergan — FDA prescribing information, indications, warnings and clinical studies, DailyMed, label dated December 2025, read 2026-09-17.
- PubChem compound records read 2026-09-17: CID 127264611 (myristoyl pentapeptide-17), 11534242 (biotinoyl tripeptide-1), 11752568 (acetyl tetrapeptide-3); no record found for oligopeptide-2.
- PubMed record counts via NCBI E-utilities, run 2026-09-17.
- Couteau C, Coiffard L. Ann Pharm Fr 2026;84(5):889-898 — the survey of 79 lash-enhancing cosmetics, as cited and linked on our myristoyl pentapeptide-17 entry.