GHK

Also known as Tripeptide-1, Gly-His-Lys, GHK tripeptide, glycyl-L-histidyl-L-lysine

The copper-free human tripeptide glycyl-L-histidyl-L-lysine (Tripeptide-1) studied for skin remodeling, collagen synthesis, and tissue-repair signaling.

Molecular weight340.38 g/mol

Half-lifeShort in plasma (minutes to low hours); declines with age in vivo. Estimates are thin for the copper-free form.

CategoryCosmetic

Typical use cases

✓ Skin firmness/anti-aging research✓ Collagen synthesis✓ Wound-healing models✓ Antioxidant signaling

Dosing guidelines

StartingResearch use is predominantly topical (e.g. serums formulated around ~0.05–0.2% / 1–2 mg/mL). Injectable research dosing is poorly characterized; some protocols extrapolate from GHK-Cu at ~1–2 mg subcutaneous.

MaintenanceTopical: applied once or twice daily per formulation. Injectable steady dosing is not well established for the copper-free peptide.

Max (studied)No validated human upper bound for the copper-free form; hedge and keep below comparable GHK-Cu research ranges.

Titration

No standardized titration; topical formulations are typically used at a fixed concentration rather than ramped.

Reconstitution

Often supplied as a 50–200 mg lyophilized vial. For topical research preparations, reconstitute in bacteriostatic water or a cosmetic base to the target concentration; specifics vary by intended use.

Injection sites

Primarily topical application to skin. If reconstituted for injectable research, subcutaneous abdomen/flank is typical, but topical is the dominant route for this peptide.

Storage & handling

Lyophilized: stable months cool/dark, longer frozen. Reconstituted: refrigerate (2–8 °C).

Side effects

Skin irritation / redness (topical) Mild · Uncommon
Injection-site reaction (if injected) Mild · Uncommon
Allergic/contact sensitivity Mild · Rare

Research summary

GHK is the metal-free tripeptide (MW 340.38) that, in vivo, binds copper(II) to form GHK-Cu; the copper-free and copper-bound forms are closely related but distinct, and much cosmetic activity is attributed to copper-dependent extracellular-matrix remodeling. In fibroblast and wound-healing models GHK/GHK-Cu has been reported to stimulate collagen and glycosaminoglycan synthesis, modulate matrix metalloproteinases, and influence antioxidant pathways. Human evidence is largely cosmetic/dermatologic and small-scale; it is generally well tolerated topically, with skin irritation the main reported issue. Educational only — not medical advice.

Key references

Pickart & Margolina, Int. J. Mol. Sci. (2018) — review of GHK/GHK-Cu in skin and tissue regeneration
Pickart, J. Biomater. Sci. Polym. Ed. (2008) — the human tripeptide GHK and tissue remodeling

Related compounds

GHK-Cu → Copper Tripeptide-1

Where to buy

🛍 Core Peptides Third-party tested ↗

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Educational reference only — not medical advice. Dosing figures are commonly-cited ranges, not prescriptions. Consult a qualified clinician.

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