For skin and hair goals, physician-prescribed compounded topical GHK-Cu from a licensed 503A compounding pharmacy is the best option, because it delivers therapeutic concentrations directly to the target tissue with physician oversight and pharmaceutical-grade quality assurance
GLP-1s may be softening demand for them
Falck E, Karlsson S, Carlsson J, Helenius G, Karlsson M, Klinga-Levan K
The 50 mg vial is reconstituted with 2 mL of bacteriostatic water to achieve a 25 mg/mL concentration (0.25 mg per unit)
(More information) Subclinical deficiency (low status) of riboflavin without clinical signs may be widespread, including in high-income countries, but it usually goes undetected because riboflavin biomarkers are very rarely measured in human studies