Neutrogena's Collagen Bank line is built around one claim, repeated on every product page: a “patented micro-peptide technology” that is “2x smaller than leading anti-aging peptides” and “penetrates more than 10 surface layers deep to support collagen”. About 3,800 US searches a month go to the range by name (clickstream estimate, October 2026). This page reads the ingredient lists Neutrogena publishes, as of 22 October 2026, and the literature on the peptide behind the claim. It judges none of the products, and nobody here has used them.
Seven lists, one peptide
The Collagen Bank collection page on neutrogena.com linked seven products with full ingredient lists on 22 October 2026. Every one names the same peptide, acetyl dipeptide-31 amide, and every one also names hydrolyzed collagen:
| Product (Neutrogena's name) | Ingredients listed | Acetyl dipeptide-31 amide | Hydrolyzed collagen | What leads the list |
|---|---|---|---|---|
| 15% Vitamin C Glow Serum | 11 | 5 | 7 | propanediol, water, ascorbic acid |
| Reviving Eye Gel Cream | 21 | 6 | 7 | water, glycerin, niacinamide |
| Collagen Bank (night) Face Moisturizer | 17 | 7 | 5 | water, glycerin, cetearyl alcohol |
| Lip Plumping Treatment (Vanilla) | 21 | 9 | 12 | hydrogenated polyisobutene, polybutene |
| Laser Perfecting Serum | 23 | 9 | 12 | water, acetyl glucosamine, glycerin |
| Daily Face Moisturizer SPF 30 (inactive list) | 28 | 10 | 9 | water, silica, caprylyl methicone |
| Glass Skin Mask (hydrogel) | 34 | 15 | 14 | water, glycerin, niacinamide |
Two further details from the lists. The Laser Perfecting Serum also declares carnosine at position 11 — a dipeptide the body makes itself (beta-alanine joined to histidine, 226.2 daltons in PubChem) — so it is the one product in the line with two peptides on its label. And the night moisturizer lists bakuchiol, a plant compound sold as a gentler retinol alternative, at position 6, directly above the peptide.
What the positions can and cannot say
US cosmetic labels list ingredients in descending order of amount, except that anything present at 1% or less may follow in any order (21 CFR 701.3). So a position near the top of a short list is consistent with more than a trace, but it does not prove it. In the vitamin C serum, for instance, the peptide comes after ascorbic acid, which the brand states is present at 15%, and before phenoxyethanol, a preservative that EU rules cap at 1%; the peptide's own level could be anywhere in between. Neutrogena states no concentration for acetyl dipeptide-31 amide on any of the seven pages.
Hydrolyzed collagen sits at similar positions across the line. On skin, hydrolyzed collagen is generally treated as a film-forming and moisturizing ingredient: its fragments are much larger than the roughly 500-dalton size commonly cited for passing the skin's outer layer, a point covered in our peptides vs collagen explainer. Neutrogena's pages make their collagen-building claims for the peptide rather than for the collagen in the jar, and that distinction holds throughout this page.
The molecule behind “micro-peptide”
The name says some of what it is: a dipeptide, two amino acids, capped with an acetyl group at one end and an amide at the other. Beyond that the public record is thin. PubChem returned no compound record for “acetyl dipeptide-31 amide” on 22 October 2026, and none of the product pages gives its amino acids, structure or molecular weight.
That makes the “2x smaller” line hard to check from outside. For scale only: palmitoyl pentapeptide-4, the Matrixyl ingredient on our Matrixyl page, is listed by PubChem at 802.1 daltons (CID 9897237), and a two-amino-acid peptide is usually well under half that. But Neutrogena does not say which “leading anti-aging peptides” it measured against, or how — and size alone does not establish what a peptide does once it is in the skin.
The patent is similarly unspecific in public. The product pages say “patented” without a number. A Google Patents full-text search for the INCI name on 22 October 2026 returned nine documents, every one assigned to Kenvue Brands, Johnson & Johnson Consumer or JNTL Consumer Health, and most are sunscreen formulations that list the peptide among their ingredients. Which document covers the peptide itself is not something the search, or the brand's pages, makes plain.
The three papers
PubMed held three records naming acetyl dipeptide-31 amide on 22 October 2026 (the quoted search "dipeptide-31" added only an unrelated 2011 protein-chemistry paper). All three appeared in the Journal of Drugs in Dermatology in 2025:
| Paper | Design, as the abstract states it | Authors |
|---|---|---|
| Edison et al., January 2025 | Cell cultures, skin samples kept alive in the lab for 8 days, lab-grown skin models; then clinical grading of a finished product over 16 weeks | Five at Kenvue Brands LLC, one at Tulane University |
| Farris et al., May 2025 (supplement) | 180 people assessed for “pre-aging” features; lab work on fibroblasts; a 12-week study of 46 people using an AM/PM regimen of the peptide, sunscreen and bakuchiol | Four of six at Kenvue Brands LLC; one at Tulane, one at Howard University |
| Supplement summary, May 2025 | Overview of the same programme | No authors listed |
The affiliations come from the journal's own article pages: Kenvue Brands LLC, Summit, New Jersey, for five of six authors on the January paper and four of six on the May paper. We found no study of the molecule by researchers outside the company on 22 October 2026. That is common for a new cosmetic peptide — our Alastin analysis found the same pattern for its octapeptide — but it means every published paper on the molecule has company authors.
What the papers measured matters as much as what they found. The January paper's collagen evidence is laboratory evidence: more procollagen, elastin, decorin, fibronectin and hyaluronic acid in cultured cells and in skin samples, against a vehicle. Its human part graded how faces looked — jawline sagging, nasolabial folds, fine lines, tone — after 16 weeks with a finished product, and reported no significant irritation. It did not take biopsies or measure collagen in the participants' skin. The abstract does not say how many people took part, whether there was a comparison group, or what else was in the formula.
The May paper's 12-week study tested a regimen of several products containing the peptide plus sunscreen and bakuchiol. When three active ingredients are used together, a change in the skin cannot be credited to one of them. The paper also introduces “pre-aging” as a category for people in their 20s and early 30s; it is the same framing the product pages use (“By your 20s, collagen levels begin to decline—up to 1% every year”).
What the product pages claim
The pages carry their own percentages. The night moisturizer: “96% showed improvement in early signs of collagen decline” and “84% saw improvement in the look of fine lines and plumper looking skin”. The SPF 30 moisturizer: 86% saw an improved look of fine lines, plumper or glowing skin, footnoted “After 4 weeks with once daily use.” The eye cream's figures are footnoted “Based on consumer perception with two times daily use over 12 weeks.” The vitamin C serum: 93% to 100% agreement figures for even tone, glow and plumpness. None of the pages states how many people were tested or whether anyone used a comparison product, and several are self-assessments rather than measurements.
The claims are phrased as appearance — “visibly”, “the look of”, “youthful-looking” — the form a cosmetic, rather than a drug, may use under the FDA's cosmetic-versus-drug distinction. “Build the collagen you don't” is the boldest line on the pages; the published evidence for it is the laboratory work described above.
What a reader can take from the lists
The lists show a single proprietary peptide carried across the whole range at mid-list positions, beside hydrolyzed collagen and, product by product, better-known actives: 15% vitamin C, niacinamide, bakuchiol, gluconolactone (a PHA exfoliant) and, in the SPF moisturizer, four sunscreen filters. They show that the peptide's evidence is recent, small, laboratory-led and published only by its maker. They cannot show how much peptide is in any jar, whether it reaches living skin in people, or how any of the seven products performs — that would take independent testing this site has not done. For how this peptide compares with the older cosmetic peptides, see our what peptides do for skin overview and our guide to reading a peptide ingredient list.
Sources
Opened 22 October 2026: neutrogena.com Collagen Bank collection page and seven product pages (ingredient lists, claim footnotes, active ingredients for the SPF 30); PubMed searches acetyl dipeptide-31 amide (3) and "dipeptide-31" (4, one unrelated), abstracts of PMIDs 39761149, 40327583 and 40327584; Crossref metadata for DOIs 10.36849/JDD.8786 and 10.36849/JDD.51181; the journal's article pages for both papers (author affiliations); PubChem name search for acetyl dipeptide-31 amide (no record) and records CID 9897237 and CID 439224; Google Patents full-text search for the INCI name (9 results); 21 CFR 701.3. Corrections go to the contact page.