Dipeptide-2 is about as small as a peptide gets: two amino acids, valine and tryptophan, joined end to end. It appears on the ingredient lists of eye creams and eye patches, usually as part of a supplier blend sold for under-eye puffiness. This page sets out what the molecule is, what the published record under its name actually contains as of 26 October 2026, and where the real literature on this exact molecule lives, which is not in skincare.
Two amino acids, 303 daltons
PubChem files the cosmetic name dipeptide-2 as a synonym of L-valyl-L-tryptophan (CID 168182), formula C16H21N3O3, 303.36 daltons. It has no fatty-acid tail and no end caps of the kind most cosmetic peptides carry.
That size matters. Most named skincare peptides are well above the roughly 500-dalton size usually quoted as the easy limit for crossing intact skin, which is why suppliers bolt palmitic acid onto them. On this site's own tables only SYN-AKE at 495.6 and copper tripeptide-1 at about 403 had cleared that line; dipeptide-2 clears it by a wider margin than either. Small enough to get in is a plausibility argument, not a measurement. No paper we found measured how much of it reaches living skin from a cream.
What 23 PubMed records are about
PubMed returned 23 records for the quoted phrase "dipeptide-2" on 26 October 2026, and the same 23 for the title-and-abstract field search. Read individually, not one concerns the skincare ingredient. They include a 2024 study of root exudates in alkali-stressed wheat, antibacterial triazine chemistry, a light-triggered hydrogel, a glutathione analogue in mice with Alzheimer's-like disease, and two 1970s papers on muscle enzymes that split "dipeptide 2-naphthylamides". The phrase turns up because chemists number compounds in a series; it is a coincidence of naming, not a body of evidence.
The supplier's trade name, Eyeliss, returned 0. As a control, the same method returns dozens of records for Argireline and acetyl hexapeptide-8.
This is the same trap our peptide hair serum page found with C-peptide in scalp hair: a literature search that is not read record by record can make an empty evidence base look like a small real one. Counted honestly, the skincare literature on dipeptide-2 under that name is zero papers.
Where the real literature is: blood pressure
Search for the molecule under its chemical name instead and a substantial, unrelated literature appears. Seventeen PubMed records join Val-Trp (or valyl-tryptophan) with angiotensin-converting enzyme, the enzyme that blood-pressure drugs such as lisinopril block. Food scientists have isolated the dipeptide from digested proteins of cauliflower by-products, wakame seaweed, shrimp, krill, jellyfish and chlorella, and several groups have tested it in spontaneously hypertensive rats.
The most cited mechanistic finding comes from the Institute of Food Chemistry in Dresden (Lunow et al. 2015, Food Chemistry): tryptophan-containing dipeptides such as Ile-Trp and Val-Trp are selective, competitive inhibitors of the enzyme's C-domain, with a selectivity factor of 70 for Val-Trp. The authors framed that as an interesting property for functional foods.
This is almost certainly why the molecule ended up in eye creams: suppliers describe puffiness partly in terms of blood-vessel and fluid regulation, and ACE sits in that system. But every one of those studies concerns the dipeptide eaten, infused or tested in a dish. None applied it to the skin around the eyes, and none says what a cosmetic amount would do there.
The supplier's one paper
The single indexed record from the supplier's own chemists is Lintner et al. 2004, "Puffy eyes: a multi-factoral cosmetic problem needs a multi-faceted solution", by authors at Sederma in France, in the Journal of Cosmetic Science. It occupies two pages, carries no abstract text in PubMed, and reports no trial data in the record. Its title states the supplier's position fairly: puffiness has several causes, so the product combines several ingredients.
The blend it usually comes in
Dipeptide-2 is rarely sold alone. The ingredient database INCIDecoder (now INKEEDecoder, read 26 October 2026) describes it as part of a three-active complex sold as Eyeliss and relays the manufacturer's own study: 20 people, 3% of the blend, improvement in 70% of them after 56 days. That study is not in PubMed, its design and comparison are not stated, and it tested the blend, not the dipeptide. The blend pairs dipeptide-2 with:
- Hesperidin methyl chalcone, a citrus flavonoid with a long record in oral venous-disease medicines, where it is combined with butcher's broom extract and vitamin C and a 2022 laboratory study showing it acts on human lymphatic smooth-muscle cells. In 2015 the dermatology department at Odense University Hospital reported it as "a new cosmetic contact allergen" (Andersen 2015, Contact Dermatitis).
- Palmitoyl tetrapeptide-7, a fatty-acid-tagged peptide covered on its own page.
Three ingredients with three different proposed jobs make a reasonable formulation idea. They also make it impossible to credit any result to dipeptide-2: no published trial compares the blend with and without it, and we found no randomized trial of the blend at all.
What the eye-area evidence looks like
For a sense of scale, a PubMed search for peptides and eye puffiness on 26 October 2026 returned nine records, among them a multi-ingredient treatment study of dark circles and puffiness, a growth-factor eye serum pilot and a 2026 review of periocular dermocosmetics. None isolates dipeptide-2. The format questions, such as why eye creams and eye patches use the peptides they do, are covered on our peptide eye cream and peptide eye patches pages; puffiness that is persistent, one-sided or new is a reason to see a clinician, because thyroid, kidney and allergic causes look the same in a mirror.
On labels
Dipeptide-2 appears on mass-market and Korean labels, usually low in the list and next to palmitoyl tetrapeptide-7. One of the three Korean serums read for our Korean peptide serum census on 4 October 2026 declares it; that page left it out of its literature counts for exactly the reason set out above. No brand we have read states how much it contains, and US labels may list anything at 1% or less in any order, so its position is a rough guide at best. How to read a peptide list position by position is explained in our guide to peptide ingredient lists.
What can fairly be said
Dipeptide-2 is valine and tryptophan, small enough to make skin penetration plausible, with a genuine pharmacology as an ACE inhibitor that was worked out by food scientists for blood pressure. Its skincare record is one two-page supplier abstract, a blend that has not been trialled with and without it, and a PubMed name search that returns 23 papers about other things. A label that lists it contains it; what it does under the eye has not been published.
Sources
Opened 26 October 2026: PubChem CID 168182 (structure, formula, weight, synonyms including "Dipeptide-2"); PubMed searches "dipeptide-2" (23, every title read), dipeptide-2[tiab] (23), eyeliss (0), ("Val-Trp" OR "valyl-tryptophan" OR "valyltryptophan") AND (angiotensin OR ACE) (17), eye puffiness peptide (9), "hesperidin methyl chalcone" (45); records PMID 25053098, 40293781, 15190902, 25801999 and 34717967; the INCIDecoder (INKEEDecoder) dipeptide-2 entry for the Eyeliss composition and the manufacturer's study as it relays it. Corrections go to the contact page.