In a study conducted by Demir [21], the effects of the anti-epileptic drugs phenytoin, gabapentin, and primidone on the GR enzyme were investigated
10.1371/journal.pone.0123454 67 SucicM.LueticK.JandricI.DrmicD.SeverA
GHK-Cu GHK-Cu ( , COPPER TRIPEPTIDE-1) - , 3 , ,
This is probably related to depletion of glutathione levels in the lungs.
This would be one injection every other week for 1 month (total 2 injections that month), then once per month or maybe 6-8 weeks, to maintain the effects - or sooner, if you feel the effects wearing off quickly
Yes, doses above 3 mg daily provide minimal additional libido benefits while significantly increasing side effects including severe nausea, hyperpigmentation, and potential cardiovascular stress