Glossary

Copper peptide: A peptide bound to a copper ion. In skincare, "copper peptide" almost always means GHK-Cu. It has been studied for a role in skin repair and the appearance of firmness.
Read the full explainer
GHK-Cu: The specific copper peptide made of three amino acids — glycine, histidine, lysine — bound to copper. The body makes it naturally, and levels tend to fall with age. It is the copper peptide active in our Recovery Lotion.
What is GHK-Cu?
Magnesium: A mineral the body needs for many everyday functions. Applied to skin as a magnesium salt, it is used mainly for comfort and recovery. Evidence for skin-barrier effects is limited.
Magnesium for skin
Peptide: A short chain of amino acids, which are the building blocks of protein. Cells use peptides as signals. GHK-Cu is one example — a peptide of three amino acids.
Barrier: The skin's outer layer, which holds moisture in and keeps irritants out. When people say their barrier is compromised, they mean this layer is stressed — often leaving skin dry, tight or reactive.
Collagen: The main structural protein in skin. It gives skin its firmness and support. The amount and quality of collagen tends to decline with age, which is part of why firmness changes over time.
Copper purge: A short adjustment period some people notice when starting a copper peptide, where skin looks briefly more reactive before it settles. It is not guaranteed. Strong or worsening irritation is a reason to stop, not a purge to push through.

Is a copper peptide the same as GHK-Cu?

In practice, yes. When a skincare label says copper peptide, it almost always means GHK-Cu — the specific copper tripeptide most studied for skin.

Is a peptide the same as collagen?

No. A peptide is a short chain of amino acids, while collagen is a large structural protein. Some peptides have been studied for how they relate to the skin's collagen systems, but they are not the same thing.

Does magnesium fix a damaged barrier?

The evidence for that is limited, so we do not claim it. Topical magnesium is used mainly for comfort and recovery. For barrier support, focus on gentle cleansing and not overdoing actives.