Topical vs injected GHK-Cu — I keep seeing people argue this and the evidence isn't symmetrical

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.

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.

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.

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.

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.

@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.

So if I'm just trying to get smoother skin, topical 2% serum is fine? No need to mess with needles?

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.'

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.

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.

Counterpoint to mothra — cosmetic industry optimizes for shelf life and FDA-friendly claims, not efficacy. Not a strong argument from incentives.

@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.

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.

Saving this whole thread. Was about to buy lyophilized GHK-Cu to inject for my face and I think I dodged a bullet.

Good thread. Rare case where the 'just use the topical' answer is the actually evidence-based one.

@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.'

Dumb question but does the copper matter or can you just use plain GHK? I see both sold.

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.

Been watching people chase topical GHK-Cu for like 5 years now and the ones who actually stick with it are the ones who understand it's not magic, just solid skincare chemistry. The injection crowd always burns out because they're waiting for systemic effects that don't really exist in the literature. Topical works, takes consistency, and costs way less than buying injectable peptides and syringes. If you're doing subq near an actual injury or surgical site, fine, maybe there's something there. But injecting it in your face hoping for collagen remodeling is just expensive LARP.

nah I think the topical crowd is overstating the penetration data too. Most of those studies are either in vitro or they're measuring it on compromised skin (wounds, stripped stratum corneum). Normal intact skin barrier is way more selective and you're probably getting WAY less than people think, especially if you're not using penetration enhancers. the "takes consistency" argument is just cope for a product that might not be doing much. not saying injection is obviously better but the "it's in cosmetic dermatology literature so it works" is picking the evidence that fits.