Health · Medical Research · 3 hrs ago
Experimental weight-loss drug cuts knee pain in clinical trials
Two clinical trials tested retatrutide in about 1,019 adults with obesity, painful knee osteoarthritis and no diabetes.
The trials found that people taking the experimental weekly injection were more likely to have knee pain fall by at least half than those given a placebo.
In a pooled analysis, about two-thirds of retatrutide users reached that level of pain relief, compared with 38% of placebo users.
Participants taking higher doses also lost substantial weight, and researchers said their ability to walk and do daily activities improved.
The findings matter because knee osteoarthritis can make everyday movement painful, and existing treatments may offer limited or temporary relief.
Gastrointestinal problems were common, and serious adverse events were more frequent with retatrutide than with placebo.
Retatrutide is not yet approved, and the trials did not establish whether it slows joint damage or reduces the need for knee replacement.
Two clinical trials found that experimental retatrutide reduced knee pain and improved mobility in people with obesity and knee osteoarthritis.
About two-thirds of participants receiving the drug had at least a 50% reduction in knee pain, compared with 38% receiving a placebo, according to a pooled analysis.
Participants on the highest dose lost about a quarter of their body weight on average, Fox News reported.
The trials were funded by Eli Lilly and published in The New England Journal of Medicine.
Retatrutide is not yet approved by the US Food and Drug Administration, and gastrointestinal problems were the most common side effects.
- Who
- More than 1,000 adults with obesity or overweight, knee osteoarthritis and no diabetes took part in the trials.
- What
- Researchers tested retatrutide, an experimental weekly injection, for knee pain and mobility.
- When
- The articles were published on November 11, 2026. Trial follow-up periods were reported as 68 and 80 weeks by Fox News; CNN Brasil reported analyses at 65 and 80 weeks.
- Where
- Northwestern University researchers led the trials. Trial locations are not stated.
- Why
- The trials assessed whether retatrutide could reduce knee pain and improve mobility in people with obesity and knee osteoarthritis.
This story does not have two clearly opposing sides.
Fox News reported that the two trials assessed participants after 68 weeks in one trial and 80 weeks in the other.
Fox News and CNN Brasil published reports on the trial findings.
- Participants
- More than 1,000 adults, according to Fox News
- Pain reduction
- About two-thirds on retatrutide had at least a 50% reduction, compared with 38% on placebo
- Weight loss
- About one-quarter of body weight on average with the highest dose
- Drug status
- Not yet FDA-approved
- Funding and publication
- Funded by Eli Lilly; published in The New England Journal of Medicine
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What people are saying
For people who are obese, not diabetic, have radiographically confirmed knee osteoarthritis that has not progressed to bone on bone, and have consistent moderate knee pain, retatrutide treatment has the potential to result in a significant and meaningful reduction in their knee pain and improvement in their physical function while providing cardiometabolic benefit
complete relief of knee pain