b12 injections route of administration Efficacy different routes of vitamin supplementation for the treatment of patients with vitamin B12 deficiency: A systematic review and network meta-analysis How to Give a B12

The first paper you see is from 1971 this discusses excessive prescription of B12 and seeks to standardise B12 treatment

Regular injections may help reduce tiredness and improve mood

Individuals under 18 years of age Pregnant or breastfeeding women Individuals with medical conditions (unless approved by a healthcare professional) Anyone advised against metabolic-active compounds Generally well tolerated, but may include: Mild skin irritation Headache Nausea Changes in energy levels Users may experience improved metabolism, increased energy, and gradual improvements in body composition with consistent use

Aging and weight management research

There are two forms of B12methylcobalamin or cyanocobalamin

The NHS confirms that taking up to 2mg (2000 micrograms) daily is unlikely to cause harm, with no established upper limit in the UK