Prescription drug costs on GreenShield's book of business rose 9.5% in 2025 to $3 billion, with semaglutide products leading the increase, according to the non-profit insurer's 2026 Drug Trends Report.
Semaglutide accounted for 6.6% of total drug costs last year and grew 47.7% year over year. The number of claimants using weight management medications rose 42% compared with 2024, making it one of the fastest-growing therapeutic categories in the data. The report drew on nearly 39 million drug claims GreenShield adjudicated in 2025.
The most extreme movement came in higher-cost diabetes therapy. Total spending on diabetes medications costing between $2,000 and $2,999 rose 594%, while the number of claimants in that bracket climbed 374.3%. GreenShield attributed the jump to the uptake of newer therapies.
Claim prevalence also rose for other chronic and common conditions, including ADHD. Prevalence of ADHD treatment among women increased 15% year over year.
Mental health medication use continued to grow, although spending growth slowed. GreenShield suggested this could reflect greater use of non-drug supports such as talk therapy.
"The real story behind these findings is the growing impact of chronic disease on Canadians and the health system that supports them," said Mark Rolnick, executive vice president and head of provider solutions at GreenShield.
Rolnick said the discussion needed to move beyond treatment to earlier intervention, prevention and more integrated care, so that new therapies deliver sustainable value for plan sponsors as well as patients.
The report also found that treatment with weight management drugs was associated with lower rates of diabetes and respiratory conditions among claimants, as well as modest reductions in inflammatory arthritis and neuropathic pain. These are associations in claims data rather than evidence that the drugs caused the improvements.
The report describes generic semaglutide as an anticipated source of competition that could ease future spending. Since the end of the period it covers, that competition has started to arrive.
In April, Health Canada approved the first generic semaglutide, a version of Ozempic, making Canada the first G7 country to do so. A second approval followed in May. In June, the regulator authorized the first generic for weight loss, a version of Wegovy, with six more submissions under review at the time.
The savings are unlikely to be immediate. Under the pan-Canadian Pharmaceutical Alliance's tiered pricing framework, first generics are priced at 75% to 85% of the brand cost, with deeper cuts only as more manufacturers enter. IB reported in July that group insurers are now pricing renewals around this.
Coverage is also widening. International Foundation of Employee Benefit Plans data cited in the same coverage showed 37% of Canadian employers now cover GLP-1 drugs for both diabetes and weight loss, more than double the share two years earlier.
GreenShield also pointed to Canadians with no drug coverage at all, which it put at more than one million people. Mandy Mail, executive vice president of GreenShield Cares, said earlier access to care and medication improved the chances of preventing more serious illness.
The insurer said its Essential Medicines Program, which provides up to $1,000 a year in drug coverage to eligible uninsured people in four provinces, has helped more than 130,000 Canadians since 2023.
For advisors heading into renewals, the 2025 figures probably mark the peak of the brand-only cost curve rather than the end of the pressure. Generic entry should lower unit costs over the next few years. But broader employer coverage for weight loss and a claimant base that grew by more than 40% in a year point to rising volume that could absorb much of the price relief.
The practical questions for sponsors are about plan design. These include whether to mandate generic substitution once more versions are available, how to structure prior authorization for weight management, and whether the downstream health benefits in GreenShield's data will translate into lower costs elsewhere in the plan. The 2026 claims will be the first real test of how much generics bend the curve.
