These two new “weight loss” drugs have been getting a lot of attention: Semaglutide, a GLP1 (glucagon like peptide 1) receptor agonist, and Tirzepatide, a dual GLP1, and GIP (glucose-dependent insulinotropic polypeptide) agonist. GLP1 and GIP are both peptides that are released in the gut in response to consuming food (or general nutrients) and work synergistically for balancing glucose and regulating postprandial metabolism. They support weight loss by reducing glycemic levels via stimulating pancreatic insulin release (reduces glucose) and reducing glucagon release (increases glucose), which also reduces appetite and slows gastric emptying. People often have fewer cravings and feel fuller longer, resulting in lower calorie intake followed by weight loss.
Tirzepatide is proving to be slightly more effective for weight loss and glucose control than semaglutide. Tirzepatide was shown to be superior in reducing weight at doses of 5 mg, 10 mg, and 15 mg compared to semaglutide at 1 mg in SURPASS-2 clinical trial. Each drug underwent a double-blind RCT. By the end of each double-blind, semaglutide being 68 weeks at once per week dosing of 2.4mg (max dose) and tirzepatide being 72 weeks with varying doses (5mg, 10mg, 15mg), tirzepatide showed a weight loss of at least -20% body weight in 30% (5mg), 50% (10mg) and 57% (15mg) of patients. Semaglutide averaged 15% body weight reduction in 50% of patients. Both are showing promising results for weight reduction and glucose control.
The most common side effects for each are gastrointestinal (e.g. nausea, reflux, constipation), though tirzepatide appears to be better tolerated with a lower adverse reaction profile. The rate of discontinuing these medications due to side effects is low, as most side effects tend to subside with ongoing use. Each medication is administered via weekly subcutaneous injection. Dosing depends on the efficacy on an individual basis but tends to increase over time. Overall, we have noticed great success among our patients with these two medications, although we do encourage monitoring by your provider. The benefits of these medications go far beyond weight and glucose control and ongoing studies are underway for alternative uses.
Written by: Emily Williams, PA-C