Topical vs injected GHK-Cu — I keep seeing people argue this and the evidence isn't symmetrical
205 posts
Every few weeks someone posts 'why inject GHK-Cu when you can just slather it on' or the mirror image 'topical is a waste, only sub-q works.' Both are oversimplifying and I want to actually lay it out.
GHK-Cu (glycyl-histidyl-lysine + Cu2+) is one of the most studied peptides we have because it's been in cosmetic dermatology literature since the 80s. The majority of the published work is topical. Penetration is real — the peptide is small (340 Da for the tripeptide, ~420 with copper), and there's good evidence it reaches the dermis at cosmetic concentrations (0.05–2% serums, roughly). You get collagen upregulation, decorin, fibroblast activity, some antioxidant effect via copper.
Injected GHK-Cu is a different animal. Systemic administration gives you circulating copper-binding peptide, which does show up in wound-healing and anti-inflammatory models, but the human clinical data is basically non-existent. Everything you read about 'injected GHK-Cu for skin' is extrapolation.
My honest take:
- For skin + hair + scars: topical is the evidence-based choice. Don't inject for cosmetic reasons.
- For systemic healing / anti-inflammatory hypothesis: maybe injection has a role, but you're in n=1 territory.
- Sub-q injections near a scar or injury site is the one case where injection for local effect has a theoretical argument, and some people swear by it. I'm skeptical but not dismissive.
What do people actually use and why?
- CJC-1295 no DAC · 100 mcg · pre-bed · sub-Q
- Ipamorelin · 200 mcg · pre-bed · sub-Q
- BPC-157 · 500 mcg · 2x/day · sub-Q
18 Replies
58 posts
Good framing. I'd add that topical GHK-Cu has the unusual property of being one of the few peptides where the topical literature outweighs the injection literature. That's the opposite of almost everything else we discuss here.
- Epithalon · 10 mg · 10d on / 80d off · sub-Q
- MOTS-c · 5 mg · 2x/wk · sub-Q
- 5-Amino-1MQ · 150 mg · daily · oral
115 posts
Pickart's own papers are the entry point. Read those before you form a strong opinion in either direction. Half the 'injected GHK-Cu does X' claims I see on Reddit don't appear anywhere in the actual literature.
119 posts
The injected-for-systemic-healing crowd is building on rodent wound models and in vitro fibroblast work. It's not nothing but it's nowhere near 'this works in humans at this dose.' The topical literature at least has controlled split-face trials in real people.
8 posts
I've done both. Topical daily on face, sub-q near my shoulder surgery site twice a week for 8 weeks. The topical I can see in the mirror. The sub-q I can't honestly separate from the rehab timeline. Won't do the sub-q again.
36 posts
People inject it because injecting feels like doing something real. Rubbing a serum on your face feels like your mom's skincare routine. It's an aesthetic-of-effort problem, not a pharmacology problem.
- Tesamorelin · 1 mg · daily AM · sub-Q
205 posts
@petal_push correct. 1–2% GHK-Cu serum, once or twice daily, clean skin, not layered with anything that'll strip the copper (vit C same application is the classic mistake). Give it 8–12 weeks before you judge.
- CJC-1295 no DAC · 100 mcg · pre-bed · sub-Q
- Ipamorelin · 200 mcg · pre-bed · sub-Q
- BPC-157 · 500 mcg · 2x/day · sub-Q
32 posts
So if I'm just trying to get smoother skin, topical 2% serum is fine? No need to mess with needles?
26 posts
I inject GHK-Cu with my TB500/BPC stack when I'm coming back from joint stuff. I can't prove it does anything on its own in that mix. But it doesn't seem to hurt either. File it under 'cheap and probably fine.'
71 posts
The fact that the cosmetic literature is stronger than the injection literature should make everyone a little uncomfortable, because cosmetic studies are notoriously weak. That bar should be higher, not lower.
17 posts
Old head perspective — this peptide has been sold in skincare since before most of this forum was born. If injection were the superior route, the cosmetic industry (which has infinite incentive to differentiate) would have moved there. They didn't. Follow the money.
- GHK-Cu · 2 mg · topical AM · topical
14 posts
Counterpoint to mothra — cosmetic industry optimizes for shelf life and FDA-friendly claims, not efficacy. Not a strong argument from incentives.
205 posts
@shoulder_spring fair, but the combined weight of cosmetic-industry investment AND independent dermatology research both landing on topical is a stronger signal than either alone.
- CJC-1295 no DAC · 100 mcg · pre-bed · sub-Q
- Ipamorelin · 200 mcg · pre-bed · sub-Q
- BPC-157 · 500 mcg · 2x/day · sub-Q
9 posts
My framework: topical for skin/scalp/scar aesthetics, no needles needed. Sub-q is experimental and should be treated as such — log it, have a stop rule, don't expect published-level results.
25 posts
Saving this whole thread. Was about to buy lyophilized GHK-Cu to inject for my face and I think I dodged a bullet.
22 posts
Good thread. Rare case where the 'just use the topical' answer is the actually evidence-based one.
205 posts
@wanderlite the copper matters a lot. GHK without Cu2+ is a different compound functionally. The copper ion is what drives a lot of the fibroblast and antioxidant effects. Don't buy 'GHK' — buy 'GHK-Cu.'
- CJC-1295 no DAC · 100 mcg · pre-bed · sub-Q
- Ipamorelin · 200 mcg · pre-bed · sub-Q
- BPC-157 · 500 mcg · 2x/day · sub-Q
17 posts
Dumb question but does the copper matter or can you just use plain GHK? I see both sold.
34 posts
The strongest version of the injected-GHK-Cu case is 'local injection adjacent to a wound site might beat topical penetration at depth.' That's it. Everything else is just wanting to inject something.