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D2C Peptides

Research goal

Peptides and skin and hair

GHK-Cu, a copper peptide used in skin and hair cosmetics, is the compound here most tied to skin care.2 Most of its human trials are small studies of facial creams,3 and no controlled trial has tested it as an injection.13 Neither blend sold for skin, Glow or KLOW, has been studied as a mixture.1619 This page maps what published sources report on each compound searched with skin and hair, and makes no promise.

This page summarizes published sources for information only. It is not medical advice and does not tell anyone to use a product. Questions about your own health belong with a licensed clinician. For questions about an order or a product, contact us.

Compounds studied for skin and hair

GHK-Cu

GHK is a three-amino-acid peptide found naturally in human plasma, at about 200 ng/mL at age 20 and 80 ng/mL by age 60.1 Its copper complex is used in skin and hair cosmetics.2 The human skin data are small and partly unpublished. Two 12-week cream studies, in 71 women (face) and 41 women (around the eyes), were reported as meeting abstracts and summarized by the group of Loren Pickart, who first isolated the peptide.4563 A 13-patient laser resurfacing study found no objective improvement in wrinkles or skin quality, although patient satisfaction was higher.78 For hair, a 2026 split-face trial in 18 adults found more and thicker eyebrow hairs on the side treated with a 2% serum.910 The hair follicle lab study often quoted for GHK-Cu tested a different copper peptide, AHK-Cu, and a scalp trial paired GHK with 5-aminolevulinic acid rather than copper.1112 Controlled trials of injected GHK-Cu are absent, and FDA says compounded injectable GHK-Cu may trigger immune reactions.1314 Read What is GHK-Cu?, or see GHK-Cu for sale.

Glow Peptide Stack

Each Glow vial is mostly GHK-Cu (50 mg), with BPC-157 (5 mg) and TB-500 (5 mg).15 The blend itself has never been tested: a PubMed search for GLOW or KLOW with these peptide names returns no records.16 Its skin case rests on the topical GHK-Cu studies above. One FDA adverse event report describes skin and gum darkening after a product containing BPC-157 and TB-500, which came back when the product was restarted.17 Read What is Glow Peptide Stack?, or see Glow Peptide Stack for sale.

KLOW Peptide Blend

KLOW combines BPC-157, TB-500, KPV and GHK-Cu in one vial without stating the amount of each.18 No published study combines even BPC-157, KPV and GHK: a PubMed search for all three returns no records.19 FDA notes that human data on injected GHK-Cu are limited.14 Read What is KLOW Peptide Blend?, or see KLOW Peptide Blend for sale.

TB-500

For hair, a 2004 study found that thymosin beta-4, the parent protein, stimulated hair growth in rats and mice.20 No hair study of TB-500 itself was found, though FDA notes it is marketed online for promoting hair growth.21 For skin, a related non-acetylated fragment improved wound closure in aged mice, a result FDA says cannot be directly extrapolated to TB-500.21 Read What is TB-500?, or see TB-500 for sale.

KPV

KPV's skin evidence is laboratory work, and FDA found no human data for it by any route.24 It protected human skin cells and a 3D skin model from damage caused by fine dust (PM10).22 In lab tests on donated human skin, it did not pass through in measurable amounts unless microneedles or a small electric current (iontophoresis) were used.23 The only KPV product proposed to FDA for compounding was a 0.1% cream or gel for wounds and conditions such as psoriasis and eczema.24 FDA found no clinical studies or human exposure data for KPV by any route.24 Read What is KPV?, or see KPV for sale.

Melanotan 2

Melanotan 2 research covers skin darkening, sexual function and appetite, and no study of it for collagen, wrinkles or hair was found.25 Its reported skin effects are darker skin,25 new and darkened moles within 24 hours of a single injection,26 and dark bands across the nails.27 In one case, gum pigmentation was still present three months after the injections stopped.28 The tanning page covers its pigment research. Read What is Melanotan 2?, or see Melanotan 2 for sale.

Epithalon

None of the human epitalon studies identified by a 2026 review measured skin, wrinkles or hair; its skin evidence comes from rat skin explants and aged rat skin cells.29 A topical serum containing epitalon among several peptides entered a small, single-group early phase 1 study in October 2026, with no results posted.30 Read What is Epithalon?, or see Epithalon for sale.

Cartalax

In aging human skin fibroblasts grown in a dish, Cartalax's tripeptide (Ala-Glu-Asp) raised collagen I and two sirtuin proteins and reduced markers of cell death.3132 No study has tested it on skin or hair in people or animals.31 Read What is Cartalax?, or see Cartalax for sale.

Vilon

In "old" human skin fibroblast cultures, Vilon's dipeptide (Lys-Glu) increased the area expressing collagen type I by 83% and sirtuin-6 by 2.6 times.33 No study has tested skin or hair outcomes in people.33 Read What is Vilon?, or see Vilon for sale.

SS-31

The only skin data come from the lab: SS-31 loaded into milk-derived exosomes reduced ultraviolet damage in human skin fibroblasts, more than SS-31 alone.34 No human skin or hair trial was found.34 Read What is SS-31?, or see SS-31 for sale.

HGH

In a 1990 study of men over 60, skin thickness rose 7.1% after 6 months of growth hormone in the 12 treated men.35 The change was not statistically significant (P = 0.07).35 Hair loss is listed among drug-related events in the GENOTROPIN label's Prader-Willi syndrome trials.36 Read What is HGH?, or see HGH for sale.

Sermorelin

Only a related analog, not sermorelin itself, has skin data.37 Over 16 weeks, a GHRH(1-29) analog increased skin thickness, measured with calipers, in both sexes among 19 adults aged 55 to 71.37 No hair data were found.37 Read What is Sermorelin?, or see Sermorelin for sale.

Compounds marketed for skin without skin or hair studies

  • CJC-1295 and ipamorelin. FDA's 2024 review lists website claims that CJC-1295 raises collagen and improves skin tone, elasticity, hair and nails, but no study of any form has tested them.38 A PubMed search for ipamorelin with hair or alopecia returns no records.40 Read What is CJC-1295 with DAC?, What is CJC-1295 No DAC?, What is CJC-1295 + Ipamorelin? and What is Ipamorelin?.
  • GHRP-2. No skin, collagen or hair study was found; a 2026 review describes its human evidence as diagnostic use plus small studies of growth hormone and appetite.41 Read What is GHRP-2?.
  • AOD-9604. FDA's 2024 review lists skin care and anti-aging among the uses clinics market it for, while the use actually studied was obesity.42 Read What is AOD-9604?.
  • MOTS-c. FDA found no clinical studies or human exposure data for MOTS-c by any route, and none of the uses proposed to it involved skin or hair.43 Read What is MOTS-c?.

Hair loss reported with weight-loss medicines

Semaglutide

No skin or hair benefit is established for semaglutide.44 Hair loss is a listed side effect of Wegovy: 3.3% of patients on 2.4 mg against 1% on placebo, and 5.8% on the 7.2 mg dose.44 Read What is Semaglutide? and semaglutide side effects.

Tirzepatide

Hair loss is also a listed side effect of Zepbound, reported in 4% to 5% of patients across doses against 1% on placebo.45 It was reported far more often in women (7.1%) than in men (0.5%).46 Read What is Tirzepatide? and tirzepatide side effects.

How to read this research

Start with where the compound went. Nearly all human skin results come from creams and serums applied to the skin, and they say little about an injected vial.3 KPV, for one, barely crosses intact skin without microneedles.23 Next, separate cells from people: collagen rising in a dish, as with Vilon and Cartalax, is a laboratory signal that no human study has followed up.3133 Check who reported the result: the best-known GHK-Cu cream results are meeting abstracts summarized by the group of the peptide's discoverer, not full peer-reviewed trials.63 Weigh objective measures over impressions: in the laser study, patients rated GHK-Cu products higher, while blinded measures found no difference.8 Finally, make sure the study tested the same molecule: AHK-Cu is not GHK-Cu, and thymosin beta-4 is not TB-500.1121 Wound healing data for GHK-Cu, including a diabetic ulcer trial, are on the healing and recovery page. The safety basics guide covers weighing research on unapproved compounds in general.

Other research goals

Frequently asked questions

Is GHK-Cu peptide good for hair growth?

The human evidence is one small study.10 In a 2026 randomized split-face trial of 18 adults, eyebrows treated with a 2% GHK-Cu serum gained hair count and diameter, while the placebo side showed no significant change.910 The hair follicle study often quoted for GHK-Cu tested AHK-Cu, a different copper peptide, and a scalp trial used GHK with 5-aminolevulinic acid instead of copper.1112 No trial of injected GHK-Cu for hair was found.13

Does the glow peptide work?

No study has tested the Glow blend of GHK-Cu, BPC-157 and TB-500: a PubMed search for the blend names with these peptides returns nothing.16 Its skin case borrows from topical GHK-Cu, where the human data are 12-week cream studies and a 13-patient laser study with no objective benefit.48 Controlled trials of injected GHK-Cu are absent,13 and FDA holds one report of skin and gum darkening with a BPC-157 and TB-500 product.17

What's the difference between klow and glow peptides?

The difference is composition. Glow's 60 mg vial holds three peptides: GHK-Cu (50 mg), BPC-157 (5 mg) and TB-500 (5 mg).15 KLOW adds a fourth peptide, KPV, to the same three in a 70 mg vial, and the supplier does not state how much of each it contains.18 Neither blend has been studied as a mixture,1619 so any difference in effect between them is unknown, and KPV itself has no human data.24

Does TB500 help with hair growth?

That has not been shown for TB-500. A 2004 study found that thymosin beta-4, its parent protein, stimulated hair growth in normal rats and mice.20 No hair study of TB-500 itself was found.21 FDA's 2026 review found no published article in which TB-500 was given to people, though it is marketed online for hair growth.21 FDA also states that TB-500 and thymosin beta-4 are not the same substance.21

Does CJC-1295 and Ipamorelin increase hair growth?

No study has shown this. A PubMed search for ipamorelin with hair or alopecia returns no records.40 FDA found no study in which any form of CJC-1295 was given to people with a disease or condition; its human studies were hormone studies in healthy volunteers.39 FDA's 2024 review lists collagen, skin elasticity, hair and nail benefits among claims made on websites, not findings from research.38

Written by D2C Peptides Editorial Team.

Pending qualified review.

Updated .

Sources

  1. Pickart L, Vasquez-Soltero JM, Margolina A. GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration. BioMed Research International, 2015.
  2. PubChem CID 71587328 record description (DrugBank). PubChem, NIH National Library of Medicine, 2026.
  3. Najafi N, et al. A Systematic Review of the Mechanisms and Therapeutic Applications of GHK-Cu in Topical Microneedle Delivery: A Case for Expanded Clinical Trials (PubMed 42787770). Archives of Internal Medicine Research, 2026.
  4. Pickart L, Margolina A. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data (facial cream study). International Journal of Molecular Sciences, 2018.
  5. Same source as 4: Margolina A. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data (eye cream study).
  6. Same source as 4: Margolina A. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data (reference list: Leyden et al., meeting abstracts).
  7. Miller TR, et al. Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin (PubMed 16847171), results. Archives of Facial Plastic Surgery, 2006.
  8. Same source as 7: conclusions.
  9. Bo SL, Nararatwanchai T, et al. The Efficacy of 2% Copper Peptide (GHK-Cu) Serum for Eyebrow Hypotrichosis (proceedings poster), results. Procedia of Multidisciplinary Research (Mae Fah Luang University authors), 2026.
  10. Mateescu DM, et al. GHK-Cu as a Bioactive Metallopeptide and Drug-Delivery Cargo (human evidence summary). Pharmaceutics, 2026.
  11. Pyo HK, et al. The effect of tripeptide-copper complex on human hair growth in vitro (PubMed 17703734). Archives of Pharmacal Research, 2007.
  12. Lee WJ, et al. Efficacy of a Complex of 5-Aminolevulinic Acid and Glycyl-Histidyl-Lysine Peptide on Hair Growth (PubMed 27489425), objective. Annals of Dermatology, 2016.
  13. Moiz A, et al. 2026 (PMC13585006): injectable GHK-Cu trials. Missouri Medicine, 2026.
  14. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (GHK-Cu, injectable routes). U.S. Food and Drug Administration, 2026.
  15. Supplier product specification.
  16. NCBI E-utilities PubMed search: 'GLOW' or 'KLOW' with peptide and GHK, BPC, TB-500 or thymosin (title/abstract). NCBI, U.S. National Library of Medicine, 2026.
  17. FDA Evaluation of BPC-157-Related Bulk Drug Substances (2026): FAERS report 26053573 outcome. U.S. Food and Drug Administration, 2026.
  18. Supplier product specification.
  19. PubMed search: (BPC-157 OR "BPC 157") AND KPV AND GHK. National Library of Medicine (PubMed E-utilities), 2026.
  20. Thymosin beta4 increases hair growth by activation of hair follicle stem cells (Philp et al., PMID 14657002). FASEB Journal, 2004.
  21. FDA Briefing Document, Pharmacy Compounding Advisory Committee, July 23-24, 2026: TB-500-Related Bulk Drug Substances (TB-500 (Free Base) and TB-500 acetate). U.S. Food and Drug Administration, 2026.
  22. Lysine-Proline-Valine peptide mitigates fine dust-induced keratinocyte apoptosis and inflammation by regulating oxidative stress and modulating the MAPK/NF-κB pathway (Sung J et al.) [PMID 40073467]. Tissue and Cell (abstract via Europe PMC REST API), 2025.
  23. Transdermal Iontophoretic Delivery of Lysine-Proline-Valine (KPV) Peptide Across Microporated Human Skin (Pawar K et al.) [PMID 28343991]. Journal of Pharmaceutical Sciences (abstract via NLM PubMed E-utilities), 2017.
  24. FDA Evaluation of KPV-Related Bulk Drug Substances (KPV (Free Base) and KPV acetate) for Inclusion on the 503A Bulk Drug Substances List, FDA briefing document for the July 23-24, 2026 PCAC meeting (memo dated 5/12/2026). U.S. Food and Drug Administration, 2026.
  25. Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study (Dorr et al., PMID 8637402), pigmentation excerpt. Life Sciences, 1996.
  26. Eruptive naevi and darkening of pre-existing naevi 24 h after a single mono-dose injection of melanotan II (Schulze et al., PMID 24334249; letter, no abstract). European Journal of Dermatology, 2014.
  27. Melanotan-associated transverse melanonychia (Paurobally et al., PMID 22182016; letter, no abstract). Journal of the European Academy of Dermatology and Venereology, 2013.
  28. Changes in Oral Mucosa Associated with Melanotan II Injections: A Case Report (Bonchev, PMID 41752902), follow-up excerpt. Life (Basel), 2026.
  29. Jain A, et al. Epitalon and Epithalamin: A Narrative Review of Mechanistic, Preclinical, and Clinical Evidence. Int J Mol Sci. 2026;27(19):8922 (PMC13664938). International Journal of Molecular Sciences (MDPI), 2026.
  30. NCT07888595: Systemic and Topical Geroprotective Rejuvenation Assessed by START/REST Aging Clocks (first posted October 22, 2026). ClinicalTrials.gov, U.S. National Library of Medicine (sponsor: Frontiers in Bioscience Research Institute and Aging), 2026.
  31. Fridman NV, et al. Comparison of the Effects of KE and AED Peptides on Functional Activity of Human Skin Fibroblasts during Their Replicative Aging. Bull Exp Biol Med. 2020;170(1):154-157. Bulletin of Experimental Biology and Medicine; record via PubMed (NLM), 2020.
  32. Lin'kova NS, et al. Peptide Regulation of Skin Fibroblast Functions during Their Aging In Vitro. Bull Exp Biol Med. 2016;161(1):175-8. Bulletin of Experimental Biology and Medicine; record via PubMed (NLM), 2016.
  33. KE (Lys-Glu, Vilon) dipeptide and aging markers in human skin fibroblasts (PubMed 29322736). Advances in Gerontology, 2017.
  34. Milk-derived exosome-loaded SS31 as a novel strategy to mitigate UV-induced photodamage in skin. Journal of Photochemistry and Photobiology B: Biology (PubMed abstract, PMID 39970726), 2025.
  35. Rudman D et al. 1990 (PMID 2355952): skin thickness. New England Journal of Medicine, via PubMed (NCBI E-utilities), 1990.
  36. GENOTROPIN prescribing information: 6.1 Clinical trials in Prader-Willi syndrome. U.S. Food and Drug Administration (Drugs@FDA label, Pfizer), 2025.
  37. Endocrine and metabolic effects of long-term administration of [Nle27]growth hormone-releasing hormone-(1-29)-NH2 in age-advanced men and women (Khorram et al.), body composition and skin. J Clin Endocrinol Metab (PubMed abstract PMID 9141536, via NCBI E-utilities), 1997.
  38. FDA Briefing Document, PCAC December 4, 2024, CJC-1295 evaluation (PDF page 25, claims made on websites). U.S. Food and Drug Administration, Center for Drug Evaluation and Research, 2024.
  39. FDA Briefing Document, Pharmacy Compounding Advisory Committee Meeting, December 4, 2024: CJC-1295-Related Bulk Drug Substances (FDA evaluation dated 11/15/2024). U.S. Food and Drug Administration, 2024.
  40. PubMed search: ipamorelin AND (hair OR alopecia) (NCBI E-utilities). National Library of Medicine (NIH), PubMed.
  41. The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration (Dominikowski A et al.). Frontiers in Endocrinology, PubMed Central, 2026.
  42. FDA Briefing Document, December 4, 2024: studied and marketed uses. U.S. Food and Drug Administration, 2024.
  43. FDA Briefing Document: Evaluation of MOTS-c-Related Bulk Drug Substances (MOTS-c (free base) and MOTS-c acetate), PCAC meeting July 23-24, 2026, memo dated 5/11/2026 (human safety section). U.S. Food and Drug Administration, 2026.
  44. WEGOVY (semaglutide) prescribing information, section 6.1 (hair loss). DailyMed, U.S. National Library of Medicine (Novo Nordisk label, revised 6/2026), 2026.
  45. ZEPBOUND Prescribing Information, revised 08/2026: Table 1 continued (placebo, 5 mg, 10 mg, 15 mg; %). U.S. Food and Drug Administration (label for Eli Lilly and Company), 2026.
  46. Same source as 45: Hair loss.