PDF) The effect of tripeptide copper complex on human hair growth in vitro GHK Cu for Hair Growth? It Works But Only If You Do It Right. Everyones talking about GHK Cu, but heres the catch most serums never make it past your scalp barrier. If the formulas too weak, it GHK Cu Hair & Scalp Serum 2400mg 4% Less Shedding Neurogan Neurogan Health Glow from within with GHK Cu Copper Peptide , This powerhouse peptide supports collagen production, skin repair, and hair follicle health, helping improve skin firmness, radiance, and support