melanotan spruta Melanotaenia Jakora Läkemedelsverket varnar för Barbie-drogen -

Generation of H 2 S in ocular tissues In mammalian cells, the generation of H 2 S is dependent on four major enzymes: cystathionine--synthase (CSE), cystathionine--lyase (CBS), 3-mercapto-methylthio pyruvate aminotransferase (3MST) and cysteine aminotransferase (CAT) 18,19

however, further research is needed to elucidate the underlying mechanisms

Technical and biological hurdles are paramount, including the inefficient delivery of cells or vectors to widespread motor neurons across the central nervous system, host immune responses that can limit efficacy or durability, and unresolved long-term safety concerns such as off-target effects or uncontrolled cell differentiation (15, 60, 65)

By increasing solubility, prolonging circulating half-life, and reducing immunogenicity, PEGylation addresses key limitations that have historically constrained the clinical use of peptides