Comparing medication-assisted weight loss with bariatric surgery

Our patients come to us seeking bariatric surgery – often gastric sleeve surgery – to achieve both a large and durable weight loss. Recently, several medications, originally devised for the treatment of diabetes, but repurposed with an indication for achieving weight loss, have hit the market. For example, semaglutide(brand name Ozempic) has good data for effective weight loss when combined with diet and exercise.

This raises the question of whether these medications can or should replace surgery. After all, medications are both literally and figuratively, an easier pill to swallow, than submitting oneself to a surgeon’s knife.

To answer this question, we should compare the data indirectly (given that there is no direct head-to-head comparison of weight loss medications against surgery) with what we know about the efficacy rates of each approach.

Per the NEJM study linked to earlier in the article, semaglutide, which is a once-weekly injection, was associated with a 14.6% loss of initial weight, with average weight loss of 33.7 lbs per patient. In this study, the average starting weight for patients was 231 lbs/ BMI 38. These results are impressive, and much more efficacious than the existing leading weight loss medication in the United States – phentermine, which is only approved for short-term use and only associated with an average of 7-7.5% weight loss.

However, when compared with bariatric surgery – with the most common approach being the gastric sleeve surgery – these results are still rather modest. On average, surgery is associated with a total reduction of 20-30% of initial body weight, with average weight loss described in the range of 70-110 lbs. This represents 2-3x the average weight loss with surgery compared to semaglutide.

Additionally, bariatric surgery is associated with significant reduction in near-term morality (30-45% reduction in the 1-2 years after surgery), and reversal of such obesity-related conditions as diabetes mellitus. These outcomes have not yet been proven in the medication-only cohort.

Of course, surgery is invasive and carries surgical-related risks, including reflux symptoms in about 20% of patients, blood clots (less than 1%), and certain nutritional deficiencies related to reduced absorptive surface area, which can be addressed with supplements. However, semaglutide is not risk-free, with the study describing that 3/4ths of patients experience nausea, vomiting, diarrhea, and constipation.

Then there is the question of cost. It is not immediately clear whether weight-loss medications like semaglutide will be covered by insurance, and if so, with what kind of copay. At face value, 1 month of semaglutide is priced at $1000. Long-term use of this medication can quickly pile on costs – for example, 10 years of taking this medication would cost a patient $120,000! Meanwhile, surgery is a fixed, one-time cost. Even without insurance coinsurance, the charge price for surgery is in the range of $20,000 – a significantly lower price, with twice as much average weight loss, and a lower rate of side effects.

Ultimately, patients should choose whichever option or combination of options that they feel most comfortable with. At our practice, we are fully in support of patients who may be interested in surgery, but only after trialing other less invasive forms of weight loss – be it diet/exercise – possibly under the supervision of a dietician or endocrinologist, or medication-assisted weight loss. Please schedule a consultation to fully understand your options!