Yes, if youre trained and guided, you can give yourself shots
Relationship between autoimmune thyroid antibodies and anti-nuclear antibodies in general patients
Others don't get enough B12 from their food, which could require vitamin B12 injections to maintain a healthy level

According to a 2018 review, GHK-Cu as a cosmetic ingredient has demonstrated the ability to:3 Tighten loose skin Reverse age-related skin thinning Repair the skins protective barrier proteins Improve skin firmness and elasticity Reduce the appearance of fine lines and wrinkles Smooth rough skin Stimulate wound healing Lessen the appearance of photodamage (sun damage), hyperpigmentation, skin spots, lesions, and more Reduce inflammation and damage from free radicals Increase hair growth and thickness Additionally, in research from 2015, the authors noted that GHK-Cu may be able to stimulate collagen, regulate the skin remodeling process, attract immune cells to the site of an injury, and restore replicative vitality to fibroblasts (a cell that helps form connective tissue) in patients whove undergone radiation therapy for cancer.2 6 GHK-Cu isnt limited to topical/cosmetic forms, however
The Essential Role of Vitamin B12 in Adult Health Vitamin B12 is key for many health aspects in adults