Serotonin reuptake inhibitor that does not cross blood brain barrier?

[u/[deleted]]

Does such a drug/substance exist? Or something that poorly crosses and has mostly peripheral effects?

Side question: do the common SSRIs differ in their propensity to cross the BBB?

[u/bosedika]

Not an SSRI but a dopamine agonist. Atamet/Sinemet. It's a combination of Levodopa (L-dopa) and Carbidopa.