Anything injectable sold today is either an outsourcing-facility product (503B, different rules, currently no 503B authorization for GHK-Cu either), a clinical-trial supply, or a research chemical being misrepresented as a pharmaceutical product
It's based on clinical data and real user timelines
In animal studies (pigs), strong systemic wound healing was induced at approximately 1.1 mg/kg body weight, roughly 300-fold below GHK-Cu's established toxic threshold in the same model
When a supplement is labeled as reduced glutathione, it means the antioxidant is in its "charged" state and ready to neutralize free radicals immediately upon absorption
Human data is limited but growing
It is important to keep in mind that these side effects are not common and usually occur only in a small percentage of people taking the supplement