Review Article
GHK-Cu may prevent oxidative stress in skin by regulating copper and modifying expression of numerous antioxidant genes
Pickart L, Margolina A. Cosmetics. 2018
Compare
GHK-Cu vs Retatrutide
Side-by-side observational reports from PeptIQ users. This compares self-reported patterns — not clinical head-to-head trials.
Last reviewed . By the PeptIQ team.
Observational reporting only — not medical advice. Does not recommend doses, protocols, or treatments.
GHK-Cu
120 community reports
Overall experience
From check-in ratings — separate from side effects logged below. Side effects are logged separately from overall experience. A favorable check-in can still include nausea, fatigue, or injection-site reactions.
Favorable 3% · Mixed 97% · Unfavorable overall 0%
Most reported benefits
Benefits users selected when logging a favorable or mixed check-in.
Mood
226
Recovery
226
Energy
1
Most logged side effects
Side effects are logged separately from overall experience. A favorable check-in can still include nausea, fatigue, or injection-site reactions.
Injection site irritation
222
Self-reported dose per injection
Median bucket: 2–3 mg · Most common: 2–3 mg
Reports span 0 to ≥ 5 mg (open-ended top bucket)
0–0.01 mg
1
0.025–0.05 mg
16
0.2–0.4 mg
4
0.6–1 mg
1
1–2 mg
71
2–3 mg
87
3–5 mg
43
5+ mg
5
Anonymized self-reports from PeptIQ users — not prescribing guidance. Buckets group similar logged amounts; open-ended top buckets mean “at least” that dose.
Commonly stacked with
How repeat users are trending
Among repeat reporters, 89% said they felt similar to their last entry, 11% more positive, and 0% more negative.
Overall, repeat reporters leaned more positive than their previous entry.
Median gap between entries: 46 days · Based on 45 repeat reporters
Retatrutide
125 community reports
Overall experience
From check-in ratings — separate from side effects logged below. Side effects are logged separately from overall experience. A favorable check-in can still include nausea, fatigue, or injection-site reactions.
Favorable 99% · Mixed 1% · Unfavorable overall 0%
Most reported benefits
Benefits users selected when logging a favorable or mixed check-in.
Appetite
222
Most logged side effects
Side effects are logged separately from overall experience. A favorable check-in can still include nausea, fatigue, or injection-site reactions.
Nausea
3
Self-reported dose per injection
Median bucket: 2–3 mg · Most common: 1–2 mg
Reports span 0 to ≥ 5 mg (open-ended top bucket)
0–0.01 mg
5
0.1–0.2 mg
3
0.2–0.4 mg
6
0.4–0.6 mg
10
0.6–1 mg
5
1–2 mg
80
2–3 mg
35
3–5 mg
17
5+ mg
61
Anonymized self-reports from PeptIQ users — not prescribing guidance. Buckets group similar logged amounts; open-ended top buckets mean “at least” that dose.
Commonly stacked with
How repeat users are trending
Among repeat reporters, 100% said they felt similar to their last entry, 0% more positive, and 0% more negative.
Overall, repeat reporters leaned similar or mixed compared to their previous entry.
Median gap between entries: 51 days · Based on 45 repeat reporters
Sources (12)
Published sources linked on the GHK-Cu and Retatrutide wiki pages.
- Wiki study page →Source
- Wiki study page →Source
PubMed
GHK-Cu in wound healing and tissue regeneration
Pickart L. J Biomater Sci Polym Ed. 2008
- Wiki study page →Source
PubMed
GHK peptide as a natural modulator of multiple cellular pathways
Pickart L, Margolina A. Biomed Res Int. 2014
- Wiki study page →Source
ClinicalTrials.gov
GHK-Cu copper peptide studies on ClinicalTrials.gov
ClinicalTrials.gov. Clinical trial registry. 2024
- Wiki study page →Source
PubMed
GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration
Pickart L, Vasquez-Soltero JM, Margolina A. BioMed research international. 2015
- Wiki study page →Source
PubMed
Biomimetic Hydrogel Scaffolds with Copper Peptide-Functionalized RADA16 Nanofiber Improve Wound Healing in Diabetes
Yang X, Zhang Y, Huang C, et al. Macromolecular bioscience. 2022
- Wiki study page →Source
PubMed
Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes
Rosenstock J, Frias J, Jastreboff AM, et al. Lancet. 2023
- Wiki study page →Source
PubMed
Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial
Jastreboff AM, Kaplan LM, Frias JP, et al. N Engl J Med. 2023
- Wiki study page →Source
ClinicalTrials.gov
Retatrutide obesity studies on ClinicalTrials.gov
ClinicalTrials.gov. Clinical trial registry. 2024
- Wiki study page →Source
ClinicalTrials.gov
Retatrutide studies on ClinicalTrials.gov
ClinicalTrials.gov. Clinical trial registry. 2024
- Wiki study page →Source
PubMed
Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial
Jastreboff AM, Kaplan LM, Frías JP, et al. The New England journal of medicine. 2023
- Wiki study page →Source
PubMed
Retatrutide-A Game Changer in Obesity Pharmacotherapy
Katsi V, Koutsopoulos G, Fragoulis C, et al. Biomolecules. 2025