The trend: GLP-1 users’ medical costs slowed over an 18- to 30-month period when they remained adherent to the drugs, according to Aon’s latest workforce analysis.

While consistent GLP-1 use slows the growth of medical expenses, employers don't see immediate savings.

• Adherence lowers medical bills: Patients who stick to their regimen (80%+ adherence) see non-drug healthcare costs drop—for Mounjaro and Ozempic users, monthly medical spend fell to $1,190 compared with $1,270 for non-users after 30 months, per Aon’s analysis.
• The “Drug Tax” remains: The savings are currently eclipsed by the cost of the drugs themselves, which add an average of $520 to $750 per GLP-1 user per month to employer expenses.
• There’s a “slower burn” for weight loss patients: For weight loss-focused brands like Wegovy and Zepbound, medical cost offsets take longer to materialize, with costs for GLP-1 users still slightly higher than non-users at the 18-month mark.
• Some long-term preventative wins: Despite the price tag, the drugs are driving down hospitalizations for major heart events and reducing diagnoses of osteoporosis and certain cancers in women.

Why it matters: GLP-1 drug prices are driving up employer-sponsored healthcare costs, but some employers are still covering the drugs they see as an important employee benefit.

• The cost of GLP-1 medications could increase premiums for employer-provided coverage by 5.3% to 13.8%, per an October study by Employee Benefit Research Institute.
• Prescription drug spending increased by 9.4% on average last year for employers with GLP-1 drugs specifically driving those costs, per a Mercer survey released in November.
• 43% of companies with 5,000 or more workers covered GLP-1s primarily for weight loss last year, and 86% of those agreed it’s important or very important to employee satisfaction, per KFF’s Employer Health Benefits survey in October.

Implications for employer health insurance: Employers face growing pressure to continue offering GLP-1 coverage, driven by increasing employee demand, expanding indications, and the need to maintain worker satisfaction, even as the drugs push up healthcare costs. In the coming year, more will have to consider if the incremental benefits that necessitate workers staying adherent are worth the continued cost.