TRIUMPH Trials
    Osteoarthritis

    TRIUMPH-4 Results: Weight Loss + Osteoarthritis Pain Relief

    Losing 71 pounds removes roughly 284 pounds of pressure from each knee. TRIUMPH-4 tests whether retatrutide can transform osteoarthritis treatment.

    Last updated: April 3, 202610 min read

    TRIUMPH-4 studies retatrutide at the intersection of obesity and osteoarthritis — two conditions that affect tens of millions of Americans simultaneously. Knee osteoarthritis is one of the most debilitating consequences of obesity, and retatrutide's capacity for 24%+ weight loss (Jastreboff et al., NEJM 2023) could produce dramatic pain relief by removing hundreds of pounds of pressure from damaged joints. This trial tests whether pharmaceutical weight loss can rival or replace surgical interventions for knee osteoarthritis.

    Trial in Progress

    TRIUMPH-4 is ongoing. This article discusses expected outcomes based on Phase 2 data and the biomechanics of weight loss on joints.

    The Biomechanics: Why Weight Matters for Knees

    The relationship between body weight and knee pressure is well-established in orthopedic literature. During normal walking, each pound of body weight translates to approximately 4 pounds of compressive force on the knee joint. This multiplier effect means:

    Weight Loss Impact on Knee Pressure

    Weight LostKnee Pressure ReducedPer 10,000 Steps
    10 lbs40 lbs per step400,000 lbs total
    25 lbs100 lbs per step1,000,000 lbs total
    50 lbs200 lbs per step2,000,000 lbs total
    71 lbs (retatrutide avg)284 lbs per step2,840,000 lbs total

    At 71 pounds lost, each day of walking removes nearly 3 million additional pounds of cumulative pressure from the knees. This is why weight loss is considered the most impactful non-surgical intervention for knee osteoarthritis.

    TRIUMPH-4 Trial Design

    • Population: Adults with obesity (BMI 30+) and symptomatic knee osteoarthritis
    • Estimated enrollment: ~800 participants
    • Duration: 68-72 weeks
    • Primary endpoints: Changes in knee pain scores and physical function
    • Secondary endpoints: Weight loss, joint stiffness, patient-reported outcomes, use of pain medications

    Precedent: Tirzepatide and Osteoarthritis

    Tirzepatide's SURMOUNT-OA trial has already demonstrated that GLP-1-based weight loss improves osteoarthritis outcomes. With retatrutide producing even greater weight loss, TRIUMPH-4 is expected to show even more pronounced benefits. This sets up a compelling case for retatrutide as a first-line treatment for obese patients with osteoarthritis.

    Beyond Pain Relief

    TRIUMPH-4 may show benefits beyond pain reduction:

    • Delayed surgery: Significant weight loss may delay or prevent the need for knee replacement
    • Improved mobility: Less pain means more physical activity, creating a positive cycle
    • Reduced inflammation: Retatrutide's metabolic effects may reduce systemic inflammation that worsens osteoarthritis
    • Medication reduction: Less need for NSAIDs and pain medications, reducing side effects from chronic pain medication use

    Start Reducing Joint Pressure Today

    Weight loss with current GLP-1 medications also reduces joint pressure significantly:

    Learn more about how to get started.

    Medical Disclaimer

    Retatrutide is an investigational drug not yet approved by the FDA. TRIUMPH-4 is ongoing. Osteoarthritis treatment should be managed by your healthcare provider. Phase 2 weight loss data from Jastreboff et al., NEJM 2023.

    Reduce Joint Pressure Today

    Every pound lost removes 4 lbs of knee pressure. Start with semaglutide from $99/mo or tirzepatide from $125/mo.

    Get Started Today

    Sources & References

    1. Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. NEJM 2021;384:989-1002.
    2. Jastreboff AM et al. Tirzepatide Once Weekly for the Treatment of Obesity. NEJM 2022;387:205-216.
    3. Lincoff AM et al. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes. NEJM 2023;389:2221-2232.
    4. FDA Prescribing Information for Wegovy (semaglutide) and Zepbound (tirzepatide).

    Medically Reviewed

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    Last reviewed: April 7, 2026

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