The rising use of GLP-1 medications for diabetes and weight management, along with continued growth in ADHD treatment, is contributing to a sharp increase in prescription drug spending across Canadian private insurance plans, according to a new report from GreenShield.
GreenShield’s 2026 Drug Trends Report found that total prescription drug costs covered by its plans increased 9.5 per cent in 2025, reaching approximately $3 billion. The analysis is based on nearly 39 million drug claims processed during the year. Diabetes and weight-management treatments were among the biggest drivers of the increase. Spending in those categories rose 47.7 per cent year over year, reflecting growing demand for newer medications and therapies used to manage chronic conditions. Semaglutide-based medications, including drugs such as Ozempic and other products used for diabetes and weight management, accounted for 6.6 per cent of total drug costs in GreenShield’s plans in 2025. Spending on semaglutide products increased 47.7 per cent compared with the previous year. The number of people making claims for weight-management medications also increased significantly. GreenShield reported a 42 per cent increase in claimants using these medications compared with 2024, making weight management one of the fastest-growing areas of prescription drug use.
The report also found substantial growth in diabetes medications in the $2,000-to-$2,999 annual cost range. Spending in that range increased 594 per cent in 2025, while the number of claimants increased 374.3 per cent.
ADHD medications are another important contributor to changing prescription-drug patterns. GreenShield reported continued growth in ADHD treatment in 2025, with the prevalence of ADHD medication claims among women increasing 15 per cent from the previous year. The increase in ADHD medication use comes as awareness and diagnosis of the condition continue to expand, particularly among adults. At the same time, the availability of generic medications is helping reduce costs for some patients and benefit plans.
Alberta Blue Cross has also identified GLP-1 medications as major drivers of drug-plan spending. Its 2026 Benefits Pulse report says semaglutide products were the top drug category by spending in its plans for the second consecutive year, while Wegovy rose sharply in its ranking as demand for weight-management treatment increased. ADHD medications, including lisdexamfetamine and methylphenidate, also remained among the higher-spending drugs. The rapid increase in GLP-1 use reflects the expanding role of these medications beyond traditional diabetes treatment. Some GLP-1 therapies are now being prescribed for weight management, increasing the number of people who may qualify for coverage and adding pressure to employer-sponsored benefit plans. The trend is also being seen in Canada’s public drug system. The Canadian Institute for Health Information reported that Ozempic alone accounted for $807 million in publicly funded prescription drug spending in 2024 and represented 8.5 per cent of the overall growth in public drug spending that year. For private insurers and employers, the rapid growth presents a challenge in balancing access to newer treatments with the long-term sustainability of drug-benefit plans. Insurers are increasingly examining tools such as formularies, prior authorization, generic substitution and other coverage-management approaches. The introduction and expansion of generic versions of some medications could eventually reduce costs. GreenShield said the expected availability of generic semaglutide could increase competition in the market and help ease some future spending pressure. The report also points to a broader shift in Canada’s health-care system. As newer treatments become available for conditions affecting larger portions of the population, medications that were once used by relatively small groups of patients can quickly become major contributors to overall health-benefit spending.
The rising cost of prescription drugs is therefore not being driven by a single medication or condition. Instead, insurers are seeing a combination of increased treatment demand, expanding use of newer therapies, chronic disease prevalence and the introduction of higher-cost medications. With GLP-1 treatments, ADHD medications and other newer therapies continuing to gain users, Canadian insurers and employers are facing growing pressure to maintain access to treatment while managing the rising cost of employee and private drug-benefit plans.