Many people taking Wegovy, Ozempic or Mounjaro notice an unexpected benefit: their joint pain improves. For some, it is the first time in years they can walk comfortably. But can GLP-1 medications really help your joints — and if so, how? Here is what the research shows.

Why does weight affect joints so much?

The link between body weight and joint pain is well-established. When you walk, the forces passing through your knee joint are several times your body weight. Research by Messier et al. (published in Arthritis & Rheumatism, 2005) found that each kilogram of body weight lost results in approximately 4 kilograms less compressive force on the knee joint per step. Over a full day of walking, this amounts to thousands of tonnes less cumulative load on the knees.

This is why weight loss is one of the most effective treatments for osteoarthritis (OA) — the most common form of joint disease. Joints that have been subjected to years of excess loading often show significant pain reduction once that load begins to decrease. The effect can be felt relatively quickly, sometimes within weeks of starting weight loss.

What do the clinical trials show?

In 2024, a landmark randomized controlled trial published in the New England Journal of Medicine (NEJMoa2403664) tested once-weekly semaglutide specifically in people with obesity and knee osteoarthritis. After 68 weeks, the results were striking:

In other words, people taking semaglutide experienced roughly 50% more pain reduction than those taking a placebo — even after accounting for the weight loss difference.

For tirzepatide (Mounjaro), analysis of the SURMOUNT-1 trial (PMC12724063, 2025) found that people with the lowest physical functioning at baseline gained the greatest benefit — an average improvement of +12.5 points in physical function in the most impaired quartile. This is particularly encouraging for people who have been significantly limited by their joint pain.

Is it just the weight loss — or is there something more?

This is an important question. The weight-loss effect alone is substantial, but research strongly suggests there is more to it than kilograms on the scale.

A 2025 systematic review (PMC11849622) examined 11 studies — 7 pre-clinical and 4 human — and confirmed that GLP-1 receptors are expressed directly in synovial tissue and cartilage. These are the tissues that line and cushion your joints. Activation of these receptors appears to:

A separate study on liraglutide (PMC6554939) confirmed these effects in a dose-dependent manner in joint tissue. In other words, GLP-1 medications may protect joints through a dual mechanism: first, by reducing mechanical load through weight loss, and second, by directly reducing inflammation in joint tissue — independent of the number on the scale.

A further study published in 2025 (PMC11729447) looked at whether GLP-1 treatment reduced the need for hip and knee replacement surgery and found encouraging early signals, though longer follow-up data is still needed to confirm this.

Who benefits the most?

Based on current evidence, people who tend to benefit most are those with:

The evidence is strongest for knee OA. Effects on hip OA, ankle joints and inflammatory forms of arthritis (such as rheumatoid arthritis) are plausible given the mechanism, but less thoroughly studied to date. If you have rheumatoid or psoriatic arthritis, speak to your rheumatologist about what the research currently supports for your specific condition.

What can you do alongside your medication?

You don't have to rely on medication alone. Several lifestyle measures have strong evidence for reducing joint pain and protecting joint health during GLP-1 treatment:

  1. Low-impact exercise: Swimming, cycling and water aerobics place minimal stress on joints while strengthening surrounding muscles. Aim for at least 150 minutes of moderate activity per week. Water-based exercise is particularly useful when pain limits land-based activity.
  2. Strength training: Muscles support and stabilize joints. Strengthening the quadriceps (for knees) and hip abductors is particularly beneficial. Even 2 sessions per week make a meaningful difference. You do not need a gym — resistance bands at home work well.
  3. Anti-inflammatory diet: Emphasize omega-3-rich foods (oily fish, flaxseed, walnuts), vegetables, whole grains and legumes, and limit processed food and added sugar. These changes complement the anti-inflammatory effects of GLP-1 medication itself.
  4. Physiotherapy: Targeted exercises from a physiotherapist addressing specific muscle groups around the affected joints are among the most evidence-based interventions for osteoarthritis. A physiotherapist can also advise on movement strategies that protect your joints during daily activities.
  5. Adequate protein: This is critical during weight loss on GLP-1 medication. Preserving muscle mass is essential for joint stability — see the companion article on muscle preservation with GLP-1 for detailed guidance.

When should you speak to your doctor?

If you have joint pain and are taking GLP-1 medication, it is worth raising this with your doctor at your next appointment. They can:

Importantly, do not reduce or change your medication doses because your joint pain is improving without first speaking to your doctor. Pain improvement is a positive sign of the treatment working, not a reason to stop.

This article provides general information only and does not constitute medical advice. Always consult your doctor about your treatment plan and joint health.

Sources