Mechanism of Action

How does Cycloset work?   

Cycloset contains bromocriptine mesylate, a sympatholytic, dopamine D2 receptor agonist.

The circadian peak of brain dopamine activity (upon daily waking) is abnormally diminished in insulin resistant states such as type 2 diabetes and results in a chronic increase in sympathetic nervous system activity which in turn causes fasting and (especially) post-meal hyperglycemia.  Morning Cycloset administration counters this abnormally diminished dopamine activity and thus reduces elevated sympathetic nervous system activity thereby improving insulin resistance and post-meal hyperglycemia without raising plasma insulin levels.

Low Brain Dopamine Activity Potentiates Chronically Elevated Sympathetic Tone to Facilitate Hyperglycemia and Type 2 Diabetes

HGP- Hepatic Glucose Production; FFA- Free Fatty Acids; TG- Triglycerides; SNS-Sympathetic Nervous System
DeFronzo, RA. Bromocriptine: A Sympatholytic, D2-Dopamine Agonist for the Treatment of Type 2 Diabetes. Diabetes Care. 2011 Apr; 34(4): 789–794


Chronically Elevated Sympathetic Tone Potentiates Hyperglycemia and Type 2 Diabetes