Each component can be dosed independently in research settings, and new combinations can be created without engineering entirely new molecules
However, with direct injection, if you do not need the additional B12, it may result in high levels in your blood that can cause side effects including gastrointestinal issues, headache and dizziness, tiredness and weakness, or skin irritation until the excess is flushed out via your kidneys and urine
These products can change how your body works and are often promoted online and on social media for "anti-aging", weight loss, bodybuilding, athletic performance, injury recovery, sleep, mental focus, or general "wellness"
After eating, protein is broken down in the stomach, and the hydrochloric acid and gastric protease release B12 into the bloodstream
Any weight loss they experience is attributable to those co-treatments, not to GHK-Cu itself