What rising GLP-1 use means for your MSK benefits strategy

The effects on MSK in the weight loss debate often goes under-reported.

GLP-1 receptor agonists such as semaglutide, liraglutide and tirzepatide were developed to improve blood sugar control in type 2 diabetes. Their effect on appetite and body weight turned them into a global weight-loss story, and that is where most of the public conversation still sits.

A quieter conversation is now emerging for benefits leaders. As GLP-1 use grows through private healthcare, wellbeing programmes and wider clinical pathways, employers need to understand what this shift means beyond weight loss alone.

The musculoskeletal (MSK) dimension of this story is underreported. MSK conditions are already one of the largest sources of absence, presenteeism and healthcare spend for employers, so how a widely prescribed drug class interacts with bone, muscle and joint health is not a marginal question.

The evidence is still developing. It varies by tissue, population and what happens alongside the drug.

Signals to watch for in higher-risk groups

A 2025 meta-analysis of 25 randomised controlled trials in people with type 2 diabetes found no significant increase in fracture risk with GLP-1 receptor agonists, alongside small improvements in bone mineral density at the hip and lower spine. An earlier 2022 systematic review reached a similar conclusion: GLP-1 receptor agonists appear to have a largely neutral effect on bone density and fracture risk in humans.

However, a 2024 phase 2 randomised trial points to a more cautious picture in higher-risk groups. In adults with increased fracture risk, mostly postmenopausal women, once-weekly semaglutide over 52 weeks was associated with higher markers of bone breakdown and lower bone density at the lower spine and hip versus placebo. The authors suggest the accompanying weight loss is likely to be a major driver.

The implication is not that GLP-1s are bad for bones. Populations matter. For older employees, postmenopausal women, and those with existing fracture risk, the question is more open.

Muscle loss with weight loss is expected, muscle quality may hold up

A 2024 review in Diabetes, Obesity and Metabolism concluded that skeletal muscle changes with GLP-1 receptor agonists appear largely proportionate to the weight lost. Reductions in lean mass broadly match what would be expected given the amount of weight lost, age and underlying disease. At the same time, improvements in insulin sensitivity and reductions in fat stored within muscle tissue may support better muscle quality, meaning how well muscle works, not just how much of it there is.

This nuance often gets lost. Significant weight loss by any route can involve lean mass loss. What matters functionally is how much strength, power and physical capacity an individual preserves. The older or more sedentary the employee, the more this matters.

Joint health is where the evidence looks most encouraging

The most positive signals sit in joint health, particularly osteoarthritis. Osteoarthritis is not simply wear and tear. It is an active joint disease driven by mechanical load and low-grade inflammation, and that mechanism matters for understanding why GLP-1 drugs might help.

A 2025 review summarises the picture. Observational studies report lower rates of progression to hip and knee replacement surgery in people with pre-existing osteoarthritis who use GLP-1 receptor agonists, slower cartilage loss on MRI in some studies, and anti-inflammatory effects inside the joint itself, where GLP-1 receptors are present on the tissue lining the joint and on cartilage cells.

The caution is substantial. Much of the clinical evidence is observational, which means the joint benefits cannot be cleanly separated from the effects of the weight loss and better blood sugar control that come with the drug. There is not yet strong evidence that GLP-1 drugs slow or reverse the disease itself in the way some specialist arthritis drugs can.

Why lifestyle & MSK support matter

The evidence across all three tissue areas points in a similar direction for benefits design. GLP-1 drugs are not a substitute for physical activity, resistance training and sleep. They act on metabolism, and the evidence suggests they work best alongside the behaviours that protect musculoskeletal health over time.

This matters for three practical reasons:

Muscle and bone risks are largely weight-loss related. Employees may be more affected if they lose significant weight without parallel strength or activity support.
Long-term outcomes depend on habits built during treatment. Employees who later stop the drug will rely on physical activity, strength training and recovery behaviours to help maintain weight, muscle mass and function.
Joint benefits may be strengthened by sustainable movement. The observational data is consistent with the well-established effect of weight loss on knee and hip load, so movement support may help amplify the same benefit.

None of this is advice to start or stop a prescription. That is a conversation between an employee and their doctor.

For benefits and wellbeing leaders, the takeaway is simpler. If GLP-1 use in your workforce is growing, MSK support is not becoming less relevant. It is becoming more important. The next step is not to treat GLP-1s as a standalone weight-loss intervention, but to connect them with a broader strategy that helps people build strength, move confidently, recover well and maintain long-term function.