There was huge news this week in the pharmaceutical world: semaglutide (Ozempic), a drug commonly used in Type 2 diabetes, delivered unprecedented results in a new weight loss trial.
In the experiment, about two thousand adults with obesity (but without diabetes) were randomly assigned to use semaglutide or a placebo for 68 weeks. Participants were also given diet & lifestyle training. The group using semaglutide lost 14.9% of its bodyweight—a total average loss of 33.6 lbs. Side effects were considered mild. The findings were published in the New England Journal of Medicine.
These numbers blew away the results from other anti-obesity drugs, none of which have proven very popular with patients and doctors, typically because they come with major side effects. To put a 14.9% weight loss in perspective, it’s about half of the average loss from bariatric surgery—an intervention that is obviously far more intense, invasive, and permanent.
Obesity experts heralded the results as “stunning,” and the authors described the study as both a “game changer” and the start of a “new era” in obesity therapy.
A truly effective weight loss pill is one of the great holy grails of the pharmaceutical industry. With global obesity still skyrocketing—nearly a billion adults worldwide are considered obese, and many more overweight—the profits from an effective weight loss drug could be almost unimaginably large.
Semaglutide was originally developed to treat Type 2 diabetes, for which it received FDA approval in 2017. It is of a class of drugs known as GLP-1 agonists, which mimic the action of a hormone named “Glucagon-like peptide 1,” which brings blood glucose levels down by enhancing the effect of insulin. The drug also appears to reduce hunger levels and therefore frequently results in weight loss. In the years since its approval, GLP-1 agonists been very popular with diabetes doctors, at least in part because of those beneficial side effects of appetite suppression and weight loss. Doctors also occasionally prescribe these drugs off-label for patients with Type 1 diabetes, although insurers rarely pay the full cost. Experts have long discussed its potential as an anti-obesity medication.
Dr. Mariela Glandt, a diabetes expert and a contributor to ASweetLife, told me that GLP-1 agonists are “a great adjuvant medication for patients who are struggling or who’ve had uncontrolled Type 2 diabetes for many years.” Dr. Glandt prefers to use the medication in combination with a low-carbohydrate diet, which itself can deliver some of the same results of increasing insulin sensitivity, curbing hunger and facilitating weight loss. “In many instances a GLP-1 helps people to start a new diet and stick to it.”
And now for the downsides:
First and foremost is cost. As some of our readers no doubt already know, semaglutide is a very expensive drug. The New York Times reports that the dosage used to treat diabetes today has an average retail price of about $1,000 a month; and the weight loss study used significantly larger doses.
Second, while side effects were “transient” and “mild-to-moderate in severity,” they were bad enough to cause 5% of the study participants to discontinue treatment due to gastrointestinal distress. Dr. Glandt guessed that “a great deal of patients do have side effects, but they can be avoided by titrating up the medication slowly.” The drugs are also known to cause an elevated heart rate, and their long-term safety is still a mystery. It will be years before we’ll really know whether or not taking the drug at high doses indefinitely is truly healthy—although, to be fair, whatever health downsides it may pose would have to outweigh the known benefits of significant weight loss.
Finally, the semaglutide will only work as long as it’s taken; to enjoy lasting weight loss, patients will almost certainly need to take the drug for the rest of their lives. Pharmacologically-induced appetite suppression, while effective, is not long-lasting. Several articles on the study delved into the experiences of study participants, and reported that as soon as the trial ended, the weight just started coming back.
Semaglutide is owned by the pharmaceutical giant Novo Nordisk, one of the big three insulin manufacturers, and is sold under the brand names Ozempic and Rybelsus. Other GLP-1 agonists on the market include the popular diabetes drugs Victoza and Trulicity, which are also known to induce at least some weight loss in patients with Type 2 diabetes. The manufacturers of other GLP-1 agonists will no doubt be racing to explore their own drugs’ potential as anti-obesity medication.