01   Results

The data
speaks clearly.

These are not marketing claims. They are outcomes from peer-reviewed clinical studies on GHK-Cu and Ectoin — the two actives in every RHIVA formula. We present the evidence as it was published.

+70%
Collagen synthesis increase
In laboratory studies measuring GHK-Cu's effect on human dermal fibroblasts. (Pickart et al.)
70%
Of volunteers showed collagen increase
In a direct human trial comparing GHK-Cu to vitamin C and retinoic acid. (Abdulghani et al., 1999)
20–30%
Improvement in skin firmness
Measured after 12 weeks of topical GHK-Cu treatment in clinical studies.
–15%
Reduction in TEWL
Transepidermal water loss reduction with Ectoin-containing emulsion. (PMC12158106)
–30%
Reduction in skin redness
Observed with Ectoin application in controlled clinical studies. (PMC12158106)
4,000+
Genes influenced
Large-scale gene expression analysis showing GHK-Cu's broad regulatory effect on tissue repair pathways.
02   Clinical Studies

Key studies
in chronological order.

1973
Discovery — Pickart & Thaler
GHK first isolated from human plasma. Demonstrated stimulation of collagen, proteoglycans, angiogenesis, and wound closure in animal and cell models. Established the foundational evidence for GHK-Cu's regenerative properties.
1988
Collagen synthesis — Maquart et al.
Demonstrated dosage-dependent increase in collagen produced by human fibroblasts incubated with GHK-Cu. Response peaked at 1 nM. Published in FEBS Letters — one of the most cited studies in copper peptide research.
1999
Human trial — Abdulghani et al.
Topical GHK-Cu compared directly against vitamin C and retinoic acid in human volunteers. GHK-Cu resulted in collagen increases in 70% of participants — outperforming both comparators in collagen production outcomes.
2009
12-week photoaging study — Leyden et al.
71 women with mild to advanced photoaging applied a GHK-Cu facial cream for 12 weeks. Results showed increased skin density and thickness, reduced fine lines, improved skin firmness, and significant overall improvement in skin appearance.
2016
MMP, TIMP, collagen & elastin — Badenhorst et al.
Investigated GHK-Cu effects on gene expression of metalloproteinases and their inhibitors, and on collagen and elastin production by human adult dermal fibroblasts. Collagen levels were above non-treated cells at 96 hours across multiple concentrations.
2018
Gene expression analysis — Pickart et al.
Using the Broad Institute's Connectivity Map, GHK-Cu was found to significantly increase expression of DNA repair genes — 47 genes stimulated, 5 suppressed. Published in International Journal of Molecular Sciences. (PMC6073405)
2022
Ectoin systematic review — PMC8850511
Systematic review of 230 references, 6 clinical trials included. Confirmed Ectoin's efficacy in improving skin hydration, reducing TEWL, and alleviating inflammatory symptoms in atopic dermatitis and barrier-compromised skin conditions.
2025
Ectoin post-laser skin study — PMC12158106
Demonstrated statistically significant reductions in TEWL (–15%), redness (–30%), and increase in hydration (+30%) with Ectoin-containing emulsions compared to placebo. Published in Molecules, June 2025.
03   What to Expect

Results require
consistency.

Week 1–2
Hydration & texture
Ectoin's hydration effects are measurable within 24–48 hours. Skin feels more resilient, TEWL decreases, and texture begins to improve as the barrier stabilises.
Week 4–6
Early structural change
GHK-Cu begins upregulating collagen and elastin synthesis. Skin biopsy studies show measurable collagen production changes from week 4. Fine lines begin to soften.
Week 8–12
Visible regeneration
The majority of clinical studies measuring skin density, firmness, and wrinkle reduction run to 12 weeks. This is the timeframe at which statistically significant improvements in skin structure are consistently measured.
12wk+
Sustained improvement
GHK-Cu's gene-regulatory effects are cumulative. Continued use maintains upregulated collagen synthesis and supports ongoing tissue remodelling. Results compound over time.
* Clinical data referenced is from peer-reviewed studies on GHK-Cu and Ectoin as isolated actives. Individual results may vary. RHIVA does not claim to diagnose, treat, or cure any skin condition.