Melanotan 1 (MT1) is a synthetic peptide analog of alpha-melanocyte stimulating hormone (alpha-MSH), an endogenous peptide hormone with effects on skin pigmentation, sexual function, appetite, and metabolism
T4 based medication like levothyroxine or Synthroid in that class of medication
Further, NICE and the BNF says that if there are neurological symptoms present, then every other day injections are the recommended treatment, so all the points you make about B12 being stored and sufficient are not really relevant
We do not market glutathione as a whitening or bleaching agent, ever
JAMA 292 (4), 490495
In some cases, the request may be denied, in which case the healthcare provider can appeal the decision, which may add additional time to the process