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They found that vitamin B12 changed the gene expression of the skin bacteria, which could have led to acne-promoting inflammation

Cerebrolysin Research Protocols & Administration Dosing in Published Research Research investigations have employed diverse Cerebrolysin doses depending on species, condition, and route: Preclinical Studies: Rat stroke models: 2.5-7.5 ml/kg optimal range (0.8-7.5 ml/kg studied) Rat TBI models: 2.5 ml/kg identified as optimal dose Mouse neurodegenerative models: 5 ml/kg typical dose Administration timing: Usually 4 hours post-injury, daily for 10-21 days Human Clinical Trials: Acute stroke: 30-50 ml/day intravenously for 10-21 days Vascular dementia: 20-30 ml/day for 4-week cycles Alzheimers disease: 10-60 ml/day for 4-24 weeks Traumatic brain injury: 30-50 ml/day for 10-21 days Important: These dosing regimens are specific to the conditions and species studied and cannot be extrapolated across species or indications due to significant differences in pharmacokinetics, peptide metabolism, receptor expression patterns, and disease pathophysiology

Active Ingredient: Cyanocobalamin, a synthetic form of vitamin B12
Others, like KPV and GHK-Cu, dont have adequate safety data in humans