Both are well-established forms of B12 that the body can use
Effect of melatonin on the outcome of assisted reproductive technique cycles in women with diminished ovarian reserve: a double-blinded randomized clinical trial
This paper will discuss the effect of GHK on gene expression relevant to nervous system functions and cognitive decline as well as review genetic and laboratory data relevant to nerve outgrowth, copper transport into cells, anxiety and pain, DNA repair, the ubiquitin proteasome system, the anti-oxidant system, changes in gene expression for glial cells, astrocytes, brain cells, dendrites, ganglia, motor neurons, Schwann cells, and sensory cells
It is a synthetic version of the naturally-occurring growth hormone-releasing hormone, and has been found to be safe and effective in clinical trials
My favorite flavor is Jello-shot
Six-week cycles have been extensively studied in research literature and provide a well-characterized timeframe for many research uses