Pinc PeptideThe girly peptide research blog

Skin & tanning · 4 compounds · updated 8 October 2026

Best peptides for skin and tanning, ranked by the human evidence

4 compounds are sold for skin and tanning. We rank them by how strong the evidence in people is, not by popularity. 1 of the 4 is FDA-approved for some use; the rest are not.

The four peptides on this page are sold for different skin goals: GHK-Cu for firmer skin and fewer wrinkles, glutathione for lighter skin, and melanotan I and melanotan II for a tan345. Melanotan I is afamelanotide, approved as the Scenesse implant for a rare disorder that makes sunlight painful678; small placebo-controlled trials found its injections darkened skin, most in fair skin that burns easily, but ‘MT1’ vials sold online for tanning are not approved591011. GHK-Cu had mixed results in small skin trials, and we found no published human study showing that injecting it on its own is safe or effective3121314. A 2025 review found that glutathione pills and creams lightened skin moderately, but said drips should not be used for lightening, because they lack effect and cause side effects15. We found only three tiny human studies of melanotan II; in the one that looked at tanning, from 1996, 2 of 3 men got darker skin161718.

Injected products bring their own risks: in 2026, at least 30 people had fever, chills or signs of shock after glutathione drips that pharmacies made from a supplement-grade ingredient, and some were hospitalized1920. Case reports link melanotan II to mole changes and melanoma, though none proves cause212223, and FDA warns that injected GHK-Cu may trigger immune reactions21. Melanotan I can darken existing moles, and FDA required at least 8 years of skin cancer follow-up for the approved implant624. Our guides to peptides in skincare and collagen peptides cover the creams, serums and supplements sold for skin.

  1. Melanotan I (afamelanotide)

    AMixed resultsApproved as Scenesse; vials are not

    Melanotan I is afamelanotide, approved as Scenesse, an implant for a rare disorder that makes sunlight painful67. Small trials found it darkens skin910, but ‘MT1’ vials sold online for tanning are not approved511.

    Does it work for tanning with less or no sun? Small placebo-controlled trials darkened skin: melanin rose 41% in fair skin that burns easily but 12% in skin that burns less easily910. Trials used near-daily injections dosed by body weight; online vials are untested.

  2. Glutathione

    BMixed resultsApproved in the Philippines with chemo; not US

    Glutathione is a natural antioxidant the body makes from three amino acids. Clinics sell drips and shots for lighter skin and wellness, but trials give little support15. In 2026, contaminated pharmacy vials sickened dozens of people1920.

    Does it work for skin lightening? Pills and creams lightened skin moderately in small trials1525. A 2025 review said drips should not be used for this, because of lack of effect and side effects15.

  3. GHK-Cu

    BMixed resultsCosmetic ingredient, not an approved drug

    GHK-Cu is a copper-carrying peptide used in skin creams and now often injected. Small skin trials had mixed results, and we found no published study that injected it on its own in people3121426.

    Does it work for firmer skin and fewer wrinkles (creams and serums)? In small skin trials, a maker-funded serum reduced wrinkle volume more than a placebo serum13, but a laser-aftercare trial found no objective benefit12. We found no study that injected it alone in people14.

  4. Melanotan II

    BUntestedNot approved for any use

    Melanotan II is a lab-made tanning peptide sold online as injections and nasal sprays. It is not approved, we found only three tiny human studies of it16171827, and case reports link it to melanoma21.

    Does it work for tanning with less or no sun? Barely tested: in the only human tanning study we found, a 1996 pilot in which all 3 men got the drug, 2 got darker skin16. We found no larger tanning or long-term safety trial2728.

How we ranked them

Compounds that trials show work for this goal come first, then those with mixed results, then those with no controlled human trial for this goal that has public results, and last those that trials found do not work. Within each group, the stronger the human evidence (tier A to E), the higher the place. Ties go to compounds FDA has approved as a medicine, then to those approved only in other countries, then to those whose US approval was withdrawn, then to peptides over non-peptide drugs, then to the winner of a trial that compared the two directly. Popularity, price and how a product is marketed play no part. A high place is not a recommendation to use anything.

How we grade evidence →

Head-to-head

Doses used in studies

Further reading

Questions people ask

Do copper peptides reduce wrinkles?

The evidence is thin: a 2026 systematic review of GHK-Cu used on its own in cosmetic medicine, covering studies up to March 2026, found only 2 randomized trials among 20 studies29. In an 8-week trial funded by the serum’s maker, wrinkle volume fell 24.1% on the side of the face treated with a GHK-Cu serum and 15.0% on the side given a placebo serum, in 20 women13. After laser skin resurfacing, GHK-Cu skin care did not improve wrinkles on objective measures in 13 patients12.

Does glutathione lighten skin?

Somewhat: a 2025 systematic review found pills and creams moderately effective in trials15. In 60 medical students, glutathione pills taken for 4 weeks lowered skin pigment at all 6 measured sites, but by significantly more than placebo at only 225. The review found only one placebo-controlled trial of drips and said they should not be used for lightening, because they lack effect and cause side effects15.

Do peptide injections work for skin?

We found no published human study showing that injecting GHK-Cu on its own is safe or effective, and FDA warns that injected GHK-Cu may trigger immune reactions31421. A 2025 review said glutathione drips should not be used for skin lightening, because they lack effect and cause side effects15. In 2026, at least 30 people had fever, chills or signs of shock after glutathione drips that pharmacies made from a supplement-grade ingredient1920.

Are tanning peptides safe?

We found no evidence that either tanning peptide on this page is safe as sold online5213031. Melanotan II’s tiny, short trials found nausea, yawning and spontaneous erections common161718, and case reports link it to mole changes, melanoma, hours-long erections and kidney injury, though none proves cause21222332. Finnrick, a testing service, failed 67 of 182 melanotan II samples it tested from February 2025 to September 202631. People choose which samples to send, so the results are not a random survey33. Melanotan I is better studied as Scenesse, an approved implant whose trials found mostly mild side effects, such as nausea, but it can darken existing moles, and FDA required at least 8 years of skin cancer follow-up6724. We found no independent tests of ‘MT1’ vials30.

What peptide is Jennifer Aniston using?

The peptide product we found her promoting is collagen peptides, a powder taken by mouth: in June 2023, NBC News reported that she was a spokesperson and the listed chief creative officer for a collagen brand, whose website quoted her adding the powder to her morning coffee or a smoothie1. In a 2025 analysis of 23 randomized trials with 1,474 people, collagen supplements improved skin hydration, elasticity and wrinkles overall, but not in the trials without drug-company funding or in the higher-quality trials2. The authors concluded that no clinical evidence supports using collagen supplements to prevent or treat skin aging2. Our collagen peptides guide covers the trials and who paid for them.

Sources

  1. 1Collagen supplement promoted by Jennifer Aniston recalled due to possible plastic contamination NBC News, 14 Jun 2023. nbcnews.com
  2. 2Effects of Collagen Supplements on Skin Aging: A Systematic Review and Meta-Analysis of Randomized Controlled Trials The American Journal of Medicine, Sep 2025. pubmed.ncbi.nlm.nih.gov
  3. 3The copper peptide trend has gone from creams to injections — ahead of the science NPR, 7 Sep 2026. npr.org
  4. 4Intravenous glutathione for skin lightening: Inadequate safety data South African Medical Journal, 6 Jul 2016. pubmed.ncbi.nlm.nih.gov
  5. 5Inside the Weird New World of Peptide Tanning GQ, 12 Aug 2026. gq.com
  6. 6SCENESSE (afamelanotide) implant prescribing information Clinuvel via DailyMed (U.S. National Library of Medicine), 11 May 2026. dailymed.nlm.nih.gov
  7. 7Afamelanotide for Erythropoietic Protoporphyria New England Journal of Medicine, 2 Jul 2015. pubmed.ncbi.nlm.nih.gov
  8. 8NDA 210797 Multi-discipline Review and Evaluation (Scenesse, afamelanotide) U.S. Food and Drug Administration, CDER, 8 Oct 2019. accessdata.fda.gov
  9. 9Induction of skin tanning by subcutaneous administration of a potent synthetic melanotropin JAMA, 20 Nov 1991. pubmed.ncbi.nlm.nih.gov
  10. 10[Nle4-D-Phe7]-alpha-melanocyte-stimulating hormone significantly increased pigmentation and decreased UV damage in fair-skinned Caucasian volunteers Journal of Investigative Dermatology, Aug 2006. pubmed.ncbi.nlm.nih.gov
  11. 11Drugs@FDA: NDA 210797, Scenesse (afamelanotide) U.S. Food and Drug Administration (Drugs@FDA), accessed 7 Oct 2026. accessdata.fda.gov
  12. 12Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin Archives of Facial Plastic Surgery, Jul 2006. pubmed.ncbi.nlm.nih.gov
  13. 13Effects of GHK-Cu on MMP and TIMP Expression, Collagen and Elastin Production, and Facial Wrinkle Parameters Journal of Aging Science, 22 Dec 2016. doi.org
  14. 14PubMed search: GHK-Cu or copper peptide names with injection terms (28 results; two injected people, each with a copper peptide as one ingredient of a hair-loss mixture) National Library of Medicine (PubMed), accessed 8 Oct 2026. pubmed.ncbi.nlm.nih.gov
  15. 15Glutathione as a skin-lightening agent and in melasma: a systematic review International Journal of Dermatology, Jun 2025. pubmed.ncbi.nlm.nih.gov
  16. 16Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study Life Sciences, 1996. pubmed.ncbi.nlm.nih.gov
  17. 17Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study The Journal of Urology, Aug 1998. pubmed.ncbi.nlm.nih.gov
  18. 18Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction Urology, 1 Oct 2000. pubmed.ncbi.nlm.nih.gov
  19. 19FDA reminds compounders not to use dietary supplement grade glutathione for injectables U.S. Food and Drug Administration, 27 Aug 2026. fda.gov
  20. 20Adverse Events Linked to Injectable Glutathione Compounded with Dietary Supplement Grade Ingredient: Current Situation U.S. Centers for Disease Control and Prevention, 15 Sep 2026. cdc.gov
  21. 21Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks U.S. Food and Drug Administration, 22 Apr 2026. fda.gov
  22. 22Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review International Journal of Dermatology, Oct 2017. pubmed.ncbi.nlm.nih.gov
  23. 23Five primary melanomas in situ in a patient with recent tanning bed use, melanotan exposure, and anabolic hormone use JAAD Case Reports, Jul 2026. pubmed.ncbi.nlm.nih.gov
  24. 24Approval letter for NDA 210797, Scenesse (afamelanotide) implant U.S. Food and Drug Administration, 8 Oct 2019. accessdata.fda.gov
  25. 25Glutathione as an oral whitening agent: a randomized, double-blind, placebo-controlled study Journal of Dermatological Treatment, Apr 2012. pubmed.ncbi.nlm.nih.gov
  26. 26Enhanced healing of ulcers in patients with diabetes by topical treatment with glycyl-l-histidyl-l-lysine copper Wound Repair and Regeneration, Oct 1994. pubmed.ncbi.nlm.nih.gov
  27. 27PubMed search: melanotan in titles or abstracts, limited to clinical trials (8 results; 4 report the three melanotan II studies, 4 test melanotan I) National Library of Medicine (PubMed), accessed 8 Oct 2026. pubmed.ncbi.nlm.nih.gov
  28. 28ClinicalTrials.gov search for ‘melanotan’ (1 study: the ‘example’ record NCT07437560) ClinicalTrials.gov, accessed 8 Oct 2026. clinicaltrials.gov
  29. 29The Regenerative Potential of GHK-Cu in Aesthetic Medicine Aesthetic Surgery Journal, 20 Aug 2026. pubmed.ncbi.nlm.nih.gov
  30. 30Melanotan I Safety Testing Results & Vendor Ratings Finnrick, accessed 7 Oct 2026. finnrick.com
  31. 31Melanotan II Safety Testing Results & Vendor Ratings Finnrick, accessed 1 Oct 2026. finnrick.com
  32. 32Melanotan II injection resulting in systemic toxicity and rhabdomyolysis Clinical Toxicology, Dec 2012. pubmed.ncbi.nlm.nih.gov
  33. 33We’d Rather Buy the Future Than Wait For It Finnrick, 10 Jun 2026. finnrick.com

Not medical advice. Each compound page cites its sources for every claim above. All compounds in one table · Report an error.