Understanding New Weight-Loss Drugs

Some individuals struggling with weight loss have found assistance through FDA-approved weight-loss medications, including bupropion plus naltrexone (Contrave), phentermine (Adipex-P), phentermine plus topiramate (Qsymia), and orlistat (Xenical, Alli). On average, these medications can help people lose 5% to 7% of their body weight when combined with a healthy diet and exercise.

Recently, a new class of medications originally used to treat type 2 diabetes has gained attention for their remarkable weight-loss results—often leading to a 10% to 20% reduction in body weight. These medications belong to the class of glucagon-like peptide-1 (GLP-1) receptor agonists.

Tale of two drugs

Two GLP-1 receptor agonists, liraglutide (Saxenda) and semaglutide (Wegovy), are FDA-approved in formulations specifically designed for weight loss in individuals without diabetes. These medications have lower-dose counterparts, known as Victoza and Ozempic, which have been used for years to help people with diabetes manage their blood sugar levels.

According to Dr. A. Enrique Caballero, an endocrinologist at Harvard-affiliated Brigham and Women’s Hospital, these medications can lead to substantial weight loss when used in conjunction with healthy lifestyle changes in individuals who are overweight or have obesity, with or without type 2 diabetes. However, their safety and appropriateness for use by individuals seeking to lose a more modest amount of weight, such as 10 to 20 pounds, remain a matter of question.

How the new drugs work

GLP-1 receptor agonists mimic the naturally released GLP-1 hormone in the gastrointestinal tract in response to eating. According to Dr. A. Enrique Caballero, these drugs stimulate the body to produce more insulin after meals, limiting the elevation of blood sugar levels, which is crucial for individuals with type 2 diabetes. Additionally, these medications regulate appetite by signaling to the brain that the body is full, thereby preventing overeating.

It’s important to note that these medications are approved for specific criteria. Wegovy and Saxenda are intended for adults diagnosed with obesity, defined as a body mass index (BMI) of 30 or higher, or those with a BMI of 27 plus at least one weight-related condition such as high blood pressure, high cholesterol, or type 2 diabetes. Victoza and Ozempic are designated for people with type 2 diabetes.

While some doctors prescribe these medications “off-label” for weight loss outside of the FDA criteria, Dr. Caballero emphasizes the lack of sufficient evidence to determine their benefits or risks for individuals falling outside these criteria. Furthermore, he underscores the importance of recognizing weight-loss medications as part of an overall strategy that includes a healthy meal plan and regular physical activity. Dr. Caballero emphasizes that without consistent and effective changes in eating and activity habits, individuals may regain the lost weight once they stop taking these medications.

Know the downsides

When considering GLP-1 receptor agonists with your doctor, it’s crucial to be aware of potential downsides. Gastrointestinal side effects such as gas, bloating, indigestion, nausea, or irregular bowel movements may occur, but these issues often resolve within a few weeks, particularly when starting with lower doses that are gradually increased to minimize side effects, as explained by Dr. Caballero.

Cost is another significant drawback, with these drugs priced at about $1,000 to $1,500 per month. Despite meeting the criteria for use, Medicare does not cover these medications for obesity, although they are covered for treating type 2 diabetes. Additionally, it’s important to note that these drugs are administered via injection into the arm, stomach, or thigh using a pen-like device with a very thin needle. Semaglutide is given weekly, while liraglutide injections are done daily. Semaglutide prescribed for diabetes is also available as a daily pill called Rybelsus, which requires waiting 30 minutes to an hour before eating or drinking.