Few patients continue weight loss drugs like Wegovy after a year — but health costs soar for all

Only around one-third of patients prescribed weight loss drugs such as Novo Nordisk's blockbuster injection Wegovy continued to take it a year later — but total health-care costs for the entire group soared, according to an analysis shared with CNBC on Tuesday.

The annual health-care cost for patients before they started a weight loss medication was $12,371 on average, said the analysis from Prime Therapeutics, one of the largest pharmacy benefit managers in the U.S. 

That cost of care jumped by nearly 60% to $19,657 on average after patients started treatment, the analysis said.

And a group of patients in the analysis who didn't take a weight loss drug saw their health-care costs decrease by 4% on average during the same time period. 

The analysis reviewed U.S. pharmacy and medical claims data for more than 4,000 people with commercial health-care plans who received new prescriptions for weight loss drugs between January and December 2021.

Those patients had a diagnosis of obesity, prediabetes, or a body mass index of 30 or higher.

Weight loss drugs are also known as GLP-1 agonists, which mimic a hormone produced in the gut to suppress a person's appetite.

The new findings highlight the hefty price tag of the highly popular weight loss medicines, most of which can cost more than $1,200 per month out of pocket. 

That cost may also be a burden for insured patients, who likely see copayments and deductibles charged by the health plans for the drugs add up over time. 

"While the industry is poised to see broader approval of GLP-1a drugs for weight loss by the Food and Drug Administration in the near-term, our analysis shows that a large, upfront financial investment is required when treating weight loss with these drugs," said Dr. Joseph Leach, Prime Therapeutics' senior vice president and chief medical officer. 

Pharmacy benefit managers such as Prime Therapeutics are middlemen who negotiate drug discounts with manufacturers on behalf of health insurers, large employers and others that contract them.

The company's analysis also suggests that adherence to treatment with Wegovy or similar drugs is poor beyond the one-year mark, which is when patients typically see substantial weight reduction.

Wegovy, for example, leads to 15% weight loss after 68 weeks, according to clinical trials on the drug.

Prime Therapeutics' analysis does not indicate why patients stopped taking weight loss drugs. 

But many users have said that the ongoing shortages of Wegovy have forced them to discontinue treatment. 

Novo Nordisk's clinical trials have shown that some patients stop treatment due to unpleasant side effects like gastrointestinal issues.

Novo Nordisk did not immediately respond to CNBC's request for comment on Prime Therapeutics' analysis.

The Danish company's stock price fell nearly 3% on Tuesday after Reuters first reported the analysis.

Pharmaceutical companies such as Eli Lilly and Pfizer started zeroing in on the weight loss industry after Wegovy and diabetes drug Ozempic, also made by Novo Nordisk, catapulted to the national spotlight in recent years.  

Social media influencers, Hollywood celebrities and billionaire tech mogul Elon Musk have reportedly used the popular injections to get rid of unwanted weight.   

But experts say the medicines may further perpetuate a dangerous diet culture that idealizes weight loss and thinness.

More than 2 in 5 adults have obesity, according to the National Institutes of Health.

About 1 in 11 adults have severe obesity.