With semaglutide now representing 6.6 per cent of total pharma cost, GreenShield tracks whether weight loss therapies are reducing plan costs downstream
Drug costs across GreenShield’s book of business rose 9.5 per cent in 2025, with semaglutide products driving a 47.7 per cent year-over-year increase to represent 6.6 per cent of total drug spend, according to GreenShield’s sixth annual Drug Trends Report.
For plan sponsors weighing the cost of weight management therapies against the promise of downstream savings, GreenShield believes their report offers the first concrete - if early - evidence that those savings may be materializing.
“We saw immediate reductions in claims activity associated with some other comorbid chronic diseases,” said Ned Pojskic, vice president of pharmacy benefits management at Toronto-based GreenShield. “Asthma was more controlled. We saw arthritis was more controlled. We even saw some early signs of pain control. There's this whole ecosystem of comorbid conditions that come with obesity that when you treat obesity, you're managing all those downstream complications. We truly believe that giving patients access to these therapies will lead to so many positive downstream consequences.”
GreenShield’s report tracks the end point of a long chain - clinical trials, prescribing decisions, and patient behaviour all funnelling into a single claims dataset. This year, two themes dominated, said Pojskic, pointing to the compounding burden of chronic disease and the role obesity plays in driving it.
Chronic disease burden doubles for overweight plan members
While Canadians are living longer, they’re also accumulating more conditions along the way, and that overlap is straining drug plans. Roughly 68 per cent of Canadians are overweight or obese, according to 2025 data published by Statistics Canada, and GreenShield’s data shows that those members carry nearly double the rate of comorbidities compared to the general population.
Five years ago, GreenShield made a deliberate choice to list weight loss therapies as standard on its formulary, treating obesity as a chronic disease rather than a lifestyle factor and claims for those therapies have grown sharply since. Pojskic sees this as validation that treating obesity produces downstream effects across comorbid conditions.
Rising drug spend doesn’t follow a straight upward line as Pojskic argues the system moves in cycles - costs climb as new therapies gain traction, then drop when generics and biosimilars enter the market. He suggests the key for plan sponsors is making sure their plans are structured to capture those offsets when they arrive.
Generic semaglutide offers plan sponsors immediate cost relief
Semaglutide is the clearest example Pojskic pointed to, noting it was the number one drug in Canada by sales, with over $3 billion on the books and went generic earlier this year. GreenShield flagged the switch in its systems in August and saw pricing fall immediately.
“Generic semaglutide, for example, is 65 per cent less costly than brand, and Ozempic has been the one drug that has really challenged drug plans in the last few years,” he said.
He noted the pattern mirrors what happened with biosimilars when high brand-name spending followed a sharp correction once lower-cost alternatives reach the market. But those corrections only benefit plans that are set up to enforce the switch. Pojskic frames that as the core obligation of a pharmacy benefits manager.
“Our job is to keep these things sustainable while balancing access to effective drugs,” he said.
Plan sponsors face long wait for GLP-1 cost offsets
According to Pojskic, every chronic disease therapy requires an upfront investment before the payoff arrives, and weight management drugs are no different. While the report does capture an early signal of downstream savings, Pojskic stresses the return horizon stretches well beyond one or two years.
The effects should compound over time - each year producing incremental gains - but plan sponsors need to calibrate expectations to a longer timeline.
He also pushes back against any suggestion that access to these therapies is open-ended. Clinical guidelines require that diet and exercise be exhausted as a first-tier intervention before weight loss medications are prescribed.
After all, as experts have previously suggested, the drugs are an adjunct, not a replacement and once a patient is on therapy, the prescription is only the starting point.
“Being on GLP-1 isn’t a matter of just taking the drug. There are important changes that need to take place in terms of how much protein they consume, for example. That’s just one of the things that need to happen to support the patient on GLP-1s,” he said.
Pojskic sees that wraparound care as essential to making the investment pay off at the plan level. Without it, patients are less likely to see sustained results — and plan sponsors are less likely to see the downstream savings the clinical evidence points to.
Still, Pojskic acknowledged that isolating the financial impact of weight management drugs is difficult because so many variables move at once. This year’s report is built on 2025 claims data, which means the generic entry of semaglutide - and the cost reduction that comes with it - won’t appear until next year’s edition. That report should show a sharp year-over-year drop in semaglutide spending.
What does show up in the current data, however, is an early signal that weight loss therapies are already affecting downstream claims activity. But Pojskic cautions against expecting a quick return as a plan member who has been obese for years might not develop a related comorbidity until three to five years later. Reversing that trajectory takes time.
“It’s challenging to trace a line directly through it, but there’s no doubt that when you look at evidence that losing weight is one of the most powerful interventions one can have on downstream comorbidities,” he said, adding GreenShield’s data shows that overweight plan members carry double the rate of conditions like anxiety, depression, and hypertension compared to the general population.
Plan sponsors weigh evidence for broader weight management coverage
That gap, he said, illustrates both the scale of the problem and the potential size of the payoff if weight loss interventions work as the clinical evidence suggests. Pojskic acknowledged the full financial picture won’t emerge quickly.
“It will take years for that to really wash through and to see those impacts,” he said, noting GreenShield is conducting follow-up studies outside the Drug Trends Report, set for publication next year, that will track savings and patient outcomes more closely.
Pojskic underscored that GreenShield’s formulary decisions don’t override plan sponsor autonomy, as individual employers will set their own direction on weight management coverage. But he emphasized GreenShield’s role is to establish a standard grounded in the best available evidence and apply it across its book of business.
That standard starts with the World Health Organization’s classification of obesity as a chronic disease. Pojskic argues the factors driving obesity are far more layered than most people recognize, pointing to genetics, the cost and availability of healthy food, and a North American built environment designed around cars rather than walking all contribute.
“When you look at them all together, you come to understand just how complex obesity is rather than thinking about it as purely an individual factor,” he said.
