Dr. Pep

Peptides · Copper tripeptide (glycyl-L-histidyl-L-lysine copper)

GHK-Cu: what the studies show

Every line below comes from a study, label or regulator record, checked by two models, with the source linked. Information, not medical advice. For adults 18+.

What it is

  • GHK-Cu is the copper-bound form of GHK (glycyl-L-histidyl-L-lysine), a three-amino-acid peptide found in human plasma, saliva and urine. Reviews say levels decline with age.[1][2]
  • It is sold in two very different ways: as a cosmetic ingredient in skin creams, and as an injectable 'research' or compounded product. The human evidence below is almost all from the skin-cream or gel side.[2][3]
  • Because the body makes GHK, papers that measure its levels are not evidence that taking it works.[1]

Bottom line

  • For topical GHK-Cu there are two small old human trials with mixed results. For injected GHK-Cu there is no real human trial: only a cosmetic injection mix of six ingredients and a one-person case report. Most of the rest is cell culture, animal work and reviews.[4][5][6][7][2]

What the human studies found

  • Topical, diabetic foot ulcers (1994): a multicentre, randomised, evaluator-blinded, placebo-controlled trial of a GHK-copper gel (lamin Gel) applied daily after debridement reported median ulcer-area closure of 98.5% versus 60.8% with vehicle (p < 0.05). The abstract does not give participant numbers. This is old and from the product's developers' era, and I found no replication in the records.[5]
  • Topical, after laser resurfacing (2006): in a randomised trial in which 13 patients finished, GHK-Cu skin-care products did not reduce redness or improve wrinkles or skin quality on objective measures. Patient questionnaires did show higher satisfaction with skin quality (p = 0.04).[4]
  • Injected, mixed formulation (2018): an open-label, single-arm pilot gave 1000 people scalp injections every 3 weeks for 8 sessions of a mix that contained VEGF, bFGF, IGF, KGF, thymosin beta-4 and copper tripeptide-1. 83% had less hair fall on a pull test. With six active ingredients and no control group, this cannot show anything about GHK-Cu alone.[6]
  • Injected or microneedled, case report (2016): one 59-year-old man had a mixed cosmetic solution (copper-GHK, hyaluronic acid, rhodiola, tranexamic acid, beta-glucan) applied with a spray device weekly for 12 weeks. Wrinkles around the eye improved and no side effects were noted. This is one patient and a multi-ingredient product.[7]
  • A 2026 systematic review says the human literature is thin and fragmented, that most randomised trials are small and use facial cosmetic creams, and that microneedle delivery has not been tested in an adequately powered human RCT.[2]

Known risks and side effects

  • Injection safety is poorly defined. FDA's category 2 page says compounded injectable GHK-Cu may carry immune-reaction risk from aggregation and impurities, and that there are limited human data to inform safety.[8]
  • The small topical and injected human studies reported no serious adverse effects, but they were short, small, or uncontrolled.[4][6][7]
  • Reviews of peptide use in sports medicine say rigorous human safety data are lacking for unapproved peptides including GHK-Cu.[9][10]

Legal status

  • Newest status (FDA 503A list, updated 2026-05-14): GHK-Cu for non-injectable routes is back in Category 1 (under evaluation). It was removed from Category 1 on 2026-04-22 when its nominations were withdrawn, then added back after one nominator said on 2026-05-05 that it meant to withdraw only the injectable nomination. FDA intends to consult its compounding advisory committee about GHK-Cu before the end of February 2027.[11]
  • As of 2026-10-09, FDA's category 2 page lists GHK-Cu (for injectable routes) among nominated-but-withdrawn substances it had flagged for significant safety risk.[8]
  • A 2020-04-01 FDA warning letter to Tailor Made Compounding LLC listed GHK-Cu among bulk substances the firm compounded that were not eligible for the 503A exemptions.[12]

Sources

  1. [1] GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration.
  2. [2] A Systematic Review of the Mechanisms and Therapeutic Applications of GHK-Cu (Glycyl-L-Histidyl-L-Lysine-Copper Complex) in Topical Microneedle Delivery: A Case for Expanded Clinical Trials.
  3. [3] Topically applied GHK as an anti-wrinkle peptide: Advantages, problems and prospective.
  4. [4] Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin.
  5. [5] Enhanced healing of ulcers in patients with diabetes by topical treatment with glycyl-l-histidyl-l-lysine copper.
  6. [6] Intradermal injections of a hair growth factor formulation for enhancement of human hair regrowth - safety and efficacy evaluation in a first-in-man pilot clinical study.
  7. [7] Significant improvement in crow's feet after treatment with Jet-M and a mixed solution of copper-GHK, oligo-hyaluronic acid, rhodiolar extract, tranexamic acid, and β-glucan (GHR formulation).
  8. [8] FDA: Certain bulk drug substances for use in compounding that may present significant safety risks (503A/503B category 2)
  9. [9] Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance.
  10. [10] Peptide Supplements and Their Therapeutic Applications in Sports Medicine.
  11. [11] FDA: Bulk drug substances nominated for use in compounding under section 503A (categories 1-3)
  12. [12] FDA: Warning Letter, Tailor Made Compounding LLC (2020-04-01), BPC-157, CJC-1295, ipamorelin, GHK-Cu, semax, selank, epitalon, DSIP, LL-37, PT-141, melanotan, MK-677, tesamorelin