Liraglutide and semaglutide are both long-acting, cardioprotective glucagon-like peptide (GLP)-1 analogs that are effective in reducing weight and controlling blood sugar in patients with type 2 diabetes. Liraglutide has a half-life of 13 hours after subcutaneous injection, suitable for once-daily dosing. Semaglutide has a longer half-life than liraglutide, lasting 165 hours, suitable for once-weekly dosing.

Differences in treating diabetes or managing weight

Liraglutide was originally produced as its focus group for weight management in obese adolescents. By targeting people aged 12 to 17, the treatment helps to alleviate the obesity epidemic before they develop into overweight or obese adults. Due to the higher half-life of semaglutide, its clinical trial research takes precedence over liraglutide. And in obese or overweight people, semaglutide 2.4mg has an absolute advantage in weight loss and lowering HbA1c. But the overall adverse event rate was also the highest, which can cause hypoglycemia. In addition, although liraglutide 3.0mg was less effective than semaglutide 2.4mg, serious adverse events were still the highest.

Side effect differences

Due to the increased dose required for semaglutide injection, side effects may be more common compared with liraglutide injection. In clinical trials, 84.1% of the semaglutide group and 82.7% of the liraglutide group reported gastrointestinal disorders such as nausea, diarrhea, indigestion, vomiting, and stomach pain. The severity of these adverse events was mild to moderate and declined naturally. However, more participants in the liraglutide group (12.6%) discontinued treatment due to serious adverse events such as ongoing medical illness or malignancy compared with the semaglutide group (3.2%). 7.9% of the semaglutide group and 11% of the liraglutide group experienced these catastrophic side effects.

There was also a slight increase in mental health-related difficulties, such as depression, anxiety, and additional fatigue, in the liraglutide group (5.5%) relative to the semaglutide group (5.4%). This was due to additional reports of insomnia and suicidal ideation in the liraglutide group.

In summary, semaglutide appears to have advantages over liraglutide in terms of diabetes treatment, weight control, frequency of use, side effects, and clinical outcomes, but this does not mean that liraglutide is not important and remains a good treatment option for patients diagnosed with type 2 diabetes in the younger population.

References:

[1] TOMONO TAKAHASHI  Masato O. [Liraglutide].[J]. Nihon rinsho. Japanese journal of clinical medicine, 2011, 69 5: 883-889.

[2] ZEYU XIE. Efficacy and Safety of Liraglutide and Semaglutide on Weight Loss in People with Obesity or Overweight: A Systematic Review.[J]. Clinical Epidemiology, 2022, 14: 1463-1476. DOI:10.2147/CLEP.S391819.

[3] J. ROSENSTOCK. 1413-P: Semaglutide 2.4 mg Improved Glucose Metabolism and Reverted Prediabetes to Normoglycemia in Adults with Overweight/Obesity vs. Liraglutide 3.0 mg (STEP 8)[J]. Diabetes, 2022. DOI:10.2337/db22-1413-p.