Overall, the limited ability of tirzepatide to cause GLP-1R desensitization through GRK2/-arrestin recruitment is consistent with its inability to induce GLP-1R internalization
This review puts forward the plausible glucose-lowering mechanism of dopamine receptor agonists, however more studies are needed to clarify the specific actions of central dopamine and prolactin and dopaminergic signaling in insulin-sensitive tissues which would identify potential therapeutic strategies for the treatment of metabolic disorders including type 2 diabetes and metabolic syndrome and even Parkinsons disease
A couple of other drugs (the anticonvulsant topiramate, and bupropion on its own) have weight-reducing tendencies and are occasionally used off-label, though neither is approved for weight management as a standalone treatment in Canada
Despite extremely promising results, Pfizer, the major funder of the work in alliance with California Biotechnology, abandoned the effort around 1991 after mistakenly concluding that the GLP-1 therapeutic approach was not worth continuing
Some barriers, such as spermicide or condoms, can be bought over-the-counter