GHK-Cu Dosage Guide: Protocols, Calculator & Safety

Dose Range

200-500 mcg SC daily (community/RUO; no clinically established injectable dose)

Frequency

Once daily subcutaneous; some run 5 days on / 2 days off. Topical: 1-2x daily to cleansed skin.

Cycle Length

Injectable (community practice): 4-8 week cycles followed by a 4-6 week off-period as a precaution against theoretical copper accumulation. Topical: continuous over 8-12+ weeks, no cycling needed.

Half-Life

~30-60 min (plasma; approximate legacy figure, no robust modern human PK study)

Common community stacks (not clinically validated): BPC-157 and TB-500 for tissue-repair synergy, KPV for anti-inflammatory and gut-skin support, and epithalon for broader anti-aging protocols. Topically it pairs well with microneedling to boost delivery, and for hair people combine it with minoxidil, finasteride, or RU-58841. Keep GHK-Cu away from strong exfoliating acids, retinoids, and high-dose L-ascorbic acid in the same session, since those can dissociate the copper complex. Injecting copper alongside other peptides does not remove the copper-accumulation concern, so off-cycles stay part of the plan.

The systemic dosing here is a single conservative microgram-scale scheme (200-500 mcg SC daily) chosen because it tracks GHK's natural plasma concentration scale and limits injected copper load; subcutaneous injection bypasses the gut's copper regulation, which is why off-cycles are common. A separate, higher-dose biohacker school runs 1-2 mg/day SC; that is noted for honesty but is not the scheme used here, and neither is backed by any human trial. For context, Pickart's animal-scaled systemic estimates land near 100-200 mg in humans, far above any biohacker dose, so the honest read is that no validated human injectable dose exists. On plasma levels: circulating GHK is roughly 200 ng/mL (about 10^-7 M) around age 20 and declines to about 80 ng/mL by age 60 (ng/mL = micrograms/L, not pg/mL). These are historical activity-based estimates from Pickart's discovery-era work, not modern LC-MS assays. None of this is medical or prescriptive dosing advice. Two field notes from the research community are worth building in. First, GHK-Cu tends to do more for people past about 40. Your body makes GHK on its own, levels run high when you are young and start sliding through the mid-30s, so younger users often report side effects without much upside because their own levels are still high. Second, GHK-Cu delivers copper, and copper and zinc push against each other. Laying down collagen raises zinc demand, so if your zinc is already low you can see acne, cracked corners of the mouth, a sore tongue, or extra shedding. Running a zinc / copper / ceruloplasmin panel first, and adding zinc (many use zinc bisglycinate) if you are on the low end, is the usual fix. None of this is medical advice. Credit where it is due: the copper/zinc balance and age framing here draw on protocol notes shared by u/Doctordup2 and others in the r/Peptides research community.