Remember that primidone is metabolized into phenobarbital
The Effects of Proton Pump Inhibitors in Acid Hypersecretion-Induced Vitamin B12 Deficiency: A Systematic Review (2022)
Metformin, commonly prescribed for type 2 diabetes, is well-known to cause diarrhoea and is also associated with B12 deficiencymeaning patients may be taking both simultaneously
GHK and DNA: Resetting the Human Genome to Health
It delivers a consistent, fixed 500 mcg serving in a familiar format, is formulated for everyday use within dietary supplement guidelines, and is third-party tested for potency, heavy metals, microbials, and allergens
The ~1-2 mg/mL serum figures circulating in community sources are DIY formulation conventions, often borrowed from how GHK-Cu cosmetic serums are mixed, rather than results of any AHK-Cu human study