There are three randomized controlled trials in PubMed joining peptides and cleansers. In two of them, the cleanser is the thing the researchers were trying to stop from mattering.
That is the whole story of this product category, and it is visible in the methods sections rather than the results.
The three trials
On 2026-09-13 we searched PubMed for peptides together with cleansers, face wash or cleansing. Forty-two records in total; three randomized controlled trials. Read individually:
| # | Year | Journal | What was randomized | What role the cleanser played |
|---|---|---|---|---|
| 1 | 2026 | J Cosmet Dermatol | Two serums — recombinant epidermal growth factor versus a human-derived growth factor — in 20 women | Control variable. All participants used a standardized cleanser and sunscreen regimen |
| 2 | 2018 | J Drugs Dermatol | A three-product alpha/beta defensin regimen versus placebo, 44 women, 12 weeks | Control variable. All patients used the same sunscreen and cleanser, which was provided to them |
| 3 | 2020 | J Cosmet Dermatol | A cleanser with 5-aminolevulinic acid and peptides versus a basic cleanser, 60 volunteers, 8 weeks | The treatment |
Two of the three are not evidence about peptide cleansers in any direction. They are evidence that researchers designing a peptide trial consider the cleanser important enough to standardise — to hand every participant the same one, so that no difference in washing can be mistaken for a difference in the product under test.
This is worth stating plainly because a citation count would not show it. A brand quoting "three randomized trials involving peptides and cleansers" would be quoting two studies that went out of their way to make the cleanser irrelevant.
The one real trial, and what it found
Lee and colleagues at Kyungpook National University randomized 60 volunteers with mild to moderate acne vulgaris to wash twice daily for 8 weeks with either a cleanser containing 5-aminolevulinic acid and peptides, or a basic cleanser. Lesions were counted every two weeks.
| Endpoint | Baseline | Week 4 | Week 8 |
|---|---|---|---|
| Inflammatory lesions (mean) | 5.9 | 4.5 | 4.1 |
| Non-inflammatory lesions (mean) | 11.4 | 8.8 | 7.4 |
Michaelson's acne severity index and investigator global assessment also fell, investigator assessment and patient satisfaction favoured the treatment group at week 8, and adverse events were similar in both arms.
Two limits belong with it. The endpoint is acne, not ageing — nothing in this trial speaks to wrinkles, firmness or collagen. And the formulation's first-named active is 5-aminolevulinic acid, a compound used in dermatology in its own right; no arm isolated it from the peptides, so the result belongs to the combination. It is a real, positive, modest finding about a finished product, and it cannot be transferred to a peptide cleanser that does not contain 5-aminolevulinic acid.
The arithmetic nobody runs
The trials that report results for topical peptides on the face use leave-on products, applied twice daily and left in place, over periods of 8 to 24 weeks. The contact is effectively continuous.
A cleanser's contact is the length of a wash. The 2020 acne trial ran for 8 weeks, which sounds comparable to a serum trial and is not: the study was long, while each individual exposure lasted as long as washing a face takes. No study of a peptide cleanser measures how much peptide remains on skin after rinsing, so how much of the difference that makes is unknown rather than small.
Our shampoo entry sets out the same rinse-off problem for hair, where the peptide record is even thinner. The comparison that makes the point is the peptide serum, the format the successful trials actually used, and the peptide moisturizer, where the barrier endpoints in this literature mostly come from.
What a peptide cleanser can honestly claim
That it cleans. That a formulation combining peptides with 5-aminolevulinic acid reduced acne lesions over 8 weeks in one trial of 60 people. That no trial has tested a peptide cleanser for any ageing endpoint.
What would settle it is a straightforward study nobody has run: a cleanser with one named peptide at a disclosed concentration, against the identical cleanser without it, with a measurement of how much peptide is left on skin after rinsing. Until deposition is measured, the case for a peptide in a rinse-off product rests on an assumption rather than a finding.
Judged as a cleanser rather than as a treatment, none of this is a criticism. Cleansers matter — every ageing trial in this set treats the choice of one as worth controlling. It is the peptide on the front of the bottle that has no evidence behind it.
Sources
- Lee HJ, Kim JY, Park KD, Lee WJ. Randomized controlled double-blind study of a cleanser composed of 5-aminolevulinic acid and peptides on mild and moderate acne vulgaris. J Cosmet Dermatol 2020;19(7):1745–50. PMID 31778021.
- Abud B, McGinn L, Cawthon E, et al. A randomized, double-blinded pilot study comparing synthetic versus human-derived topical epidermal growth factor for facial rejuvenation. J Cosmet Dermatol 2026;25(5):e70927. PMID 42152512.
- Taub A, Bucay V, Keller G, et al. Multi-center, double-blind, vehicle-controlled clinical trial of an alpha and beta defensin-containing anti-aging skin care regimen. J Drugs Dermatol 2018;17(4):426–41. PMID 29601620.
- PubMed search, run 2026-09-13: peptide(s) AND (cleanser* OR face wash OR cleansing) — 42 records, of which 3 carry the randomized controlled trial publication type.