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
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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.
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%
Benefits users selected when logging a favorable or mixed check-in.
Side effects are logged separately from overall experience. A favorable check-in can still include nausea, fatigue, or injection-site reactions.
Median bucket: 2–3 mg · Most common: 2–3 mg
Reports span 0 to ≥ 5 mg (open-ended top bucket)
Anonymized self-reports from PeptIQ users — not prescribing guidance. Buckets group similar logged amounts; open-ended top buckets mean “at least” that dose.
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
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 98% · Mixed 2% · Unfavorable overall 0%
Benefits users selected when logging a favorable or mixed check-in.
Side effects are logged separately from overall experience. A favorable check-in can still include nausea, fatigue, or injection-site reactions.
Median bucket: 5+ mg · Most common: 5+ mg
Reports span 0.2 to ≥ 5 mg (open-ended top bucket)
Anonymized self-reports from PeptIQ users — not prescribing guidance. Buckets group similar logged amounts; open-ended top buckets mean “at least” that dose.
Among repeat reporters, 96% said they felt similar to their last entry, 4% more positive, and 0% more negative.
Overall, repeat reporters leaned more positive than their previous entry.
Median gap between entries: 66 days · Based on 26 repeat reporters
Published sources linked on the GHK-Cu and Glutathione wiki pages.
Review Article
Pickart L, Margolina A. Cosmetics. 2018
PubMed
Pickart L. J Biomater Sci Polym Ed. 2008
PubMed
Pickart L, Margolina A. Biomed Res Int. 2014
ClinicalTrials.gov
ClinicalTrials.gov. Clinical trial registry. 2024
PubMed
Pickart L, Vasquez-Soltero JM, Margolina A. BioMed research international. 2015
PubMed
Yang X, Zhang Y, Huang C, et al. Macromolecular bioscience. 2022
PubMed
Richie JP Jr, Nichenametla S, Neidig W, et al. Eur J Nutr. 2015
PubMed
Davids LM, van Wyk JC, Khumalo NP. S Afr Med J. 2016
PubMed
Liu JD, Liu WB, Zhang CY, et al. Fish & shellfish immunology. 2020
PubMed
Hsiao YF, Huang SC, Cheng SB, et al. International journal of molecular sciences. 2024