GLP-1 drugs were approved to treat diabetes based on large studies that showed they significantly lower blood sugar levels.
In one major trial, weekly doses of 0.5 milligrams (mg) and 1 mg of semaglutide for 30 weeks lowered A1C by 1.45 percent and 1.55 percent, respectively, in participants with type 2 diabetes. They were not receiving any other diabetes treatment and had an average starting A1C of approximately 8 percent.
The second trial tested a 2 mg weekly dose of semaglutide and a 1 mg weekly dose of semaglutide over 40 weeks in participants with poorly controlled diabetes (average A1C starting at 8.9 percent). The 2 mg dose lowered participants’ A1C by an average of 2.2 percentage points, while the 1 mg dose lowered their A1C by an average of 1.9 percentage points.
Meanwhile, a pivotal trial of tirzepatide found that dual administration of GIP/GLP-1 was even more effective than semaglutide in lowering A1C by 2.01, 2.24, and 2.3 percentage points at weekly doses of 5 mg, 10 mg, and 15 mg.
In another 40-week study, weekly doses of 15 mg of tirzepatide reduced A1C by up to 2.07 percentage points and weight by up to 9.5 kilograms (kg). This equates to 20.9 pounds (pounds). They also noted that tirzepatide kept average blood sugar levels below 140 mg/dL two hours after a meal, a threshold considered normal in healthy people without diabetes.
“Importantly from a metabolic perspective, the improvement is closely related to meaningful weight loss and improvement in insulin resistance. This supports the increasing treatment of type 2 diabetes as part of a broader chronic metabolic disease caused by excess fat accumulation (body fat),” Abdelmasi says.
