Andrew Huberman· PhD
the simple way to look at this is that melanotan one does not cross the bloodb brain barrier it does however stimulate the melanocytes of the skin so it leads to tanning or darkening of the skin melanotan 2 3 4 and five also lead to darkening the skin by way of activating melanocytes in the skin but because they can cross the blood brain barrier they cause effects that are at the level of psychology really and at the level of appetite and things of that sort
Verbal pushback — no audited source on record.
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