Skin + Hair Stack: GHK-Cu + AHK-Cu

Copper peptides are the quiet corner of the peptide world. They don't do anything dramatic to how you feel — nothing about these will make you train harder or sleep deeper. But six months in, the people running them are the ones whose skin looks inexplicably good for their age and whose hairline isn't where you'd expect it to be.

GHK-Cu has been studied for decades. AHK-Cu is newer to the community conversation but has a narrower, more specific use case. Together they form the working skin-and-hair protocol.

Who this is for

• Someone 35+ wanting to slow visible skin aging rather than chase correction
• Early-stage androgenetic hair thinning (before you'd consider finasteride or along with it)
• Post-sun-damage repair projects
• Scar softening on older scars

The compounds

• GHK-Cu — 2-3 mg/day topical applied to face/neck, OR 1-2 mg sub-Q 3-5x per week for systemic. Many users do both.
• AHK-Cu — 1-2 mg topical applied to scalp daily, OR injected into scalp 2x per week (advanced, not required)

Weekly schedule

Day	AM	PM
Mon	GHK-Cu topical (face/neck) + AHK-Cu scalp	GHK-Cu 1.5 mg sub-Q
Tue	GHK-Cu topical + AHK-Cu scalp	—
Wed	GHK-Cu topical + AHK-Cu scalp	GHK-Cu 1.5 mg sub-Q
Thu	GHK-Cu topical + AHK-Cu scalp	—
Fri	GHK-Cu topical + AHK-Cu scalp	GHK-Cu 1.5 mg sub-Q
Sat	GHK-Cu topical	—
Sun	GHK-Cu topical	—

Topicals go on clean skin (after gentle cleansing, before moisturizer). Injections go in any sub-Q site, same rules as any peptide.

Why the two together

GHK-Cu is a tripeptide (Gly-His-Lys) naturally found in human plasma that declines with age. It's been studied for collagen synthesis, glycosaminoglycan production, and extracellular matrix remodeling — the structural side of younger-looking skin. It also has wound-healing and anti-inflammatory properties.

AHK-Cu (alanine-histidine-lysine copper) shows research-level activity on follicular dermal papilla cells — the cells that decide whether a follicle grows thick terminal hair or weak vellus hair. The two peptides overlap in copper delivery but target different tissue projects.

Running GHK for skin, AHK for scalp, covers the full surface-level aging picture.

Topical vs injection

• Topical is how most people run these. Copper peptides penetrate the skin reasonably well. It's slow but cumulative and has the fewest logistics.
• Sub-Q injection adds systemic exposure and is where the more dramatic wound-healing and connective tissue benefits are reported.
• Scalp injection (mesotherapy-style) for AHK-Cu is the most aggressive follicular delivery but requires technique and is not for beginners.

Starting topical-only for the first 4-8 weeks to confirm tolerance is the conservative path.

Ramp-up and cycling

Copper peptides are generally well-tolerated. If using topically, patch-test a small area for 48 hours first — rare users get a copper-contact dermatitis reaction.

Cycling is looser than with systemic peptides. Many users run these indefinitely. A conservative 12-weeks-on, 2-weeks-off pattern is common for injection protocols; topicals often run continuously.

What to expect

• Week 1-4: Skin looks slightly better hydrated. Not dramatic.
• Month 2-3: Texture shift — smoother, better light response. Partners may notice before you do.
• Month 4-6: Fine lines softening. For hair: shedding often decreases in month two, then new velus conversion takes months more.
• Month 6-12: Cumulative collagen changes become visible. Hair density improvements — if they're coming — are visible now.

This is the longest timeline of any protocol on PepAtlas. Patience is the feature.

Cost ballpark

Topical GHK-Cu serums run $40-120 per bottle and last 1-3 months depending on area. Injectable GHK-Cu powder is $20-60 per 50 mg vial. AHK-Cu is in a similar range. A full six-month run is generally $300-600.

Red flags — when to stop

• Copper-contact dermatitis (rare, presents as pink/itchy rash at application site)
• Darkening of moles or new pigmentation changes — have them checked
• Persistent headaches (extremely rare but reported with high-dose systemic)
• For AHK-Cu specifically, temporary increased shedding in the first 4-6 weeks is common and not a reason to stop — but persistent shedding beyond month three warrants reassessment

Where to go next

• The Pepperpedia GHK-Cu entry has the full collagen/ECM mechanism.
• For scar and wound-healing specific use, see the healing stack.
• The glow stack on Pepperpedia layers GHK with BPC-157 and TB-500 for more aggressive skin projects.
• Real-world results and topical brand discussions are in the Protocol Discussions forum.