Health · Pharma & Biotech · 1 hr ago
Study finds 129 symptoms reported by users of unlicensed weight-loss drug
A study found 129 symptoms reported by people claiming to use retatrutide, an experimental weight-loss drug also known as “reta.”
Researchers at the University of Pennsylvania analysed Reddit posts, identifying 13,589 people who said they used it.
Of those, 7,823 reported at least one side effect, including fatigue, nausea, increased appetite and changes in heart rate or mental health.
Retatrutide targets three hormone receptors and has drawn attention after trials found it could lead to substantial weight loss.
The drug is not licensed anywhere and remains in clinical trials, but people in the UK and elsewhere are buying it illegally and injecting it.
Experts warn that unlicensed products may not contain what they claim and have not passed safety checks.
The Reddit reports could not be verified, so the findings do not prove that retatrutide caused the symptoms; the drug’s trials are still ongoing.
A study found that people claiming to use unlicensed weight-loss drug retatrutide reported 129 different symptoms on Reddit.
Researchers examined 148,640 posts and identified 13,589 people who claimed to be using the drug.
Of those users, 7,823 reported at least one side effect, with increased appetite the most commonly reported symptom.
Retatrutide is still undergoing clinical trials and is not licensed for use anywhere in the world.
The study’s authors could not verify the claims made in the posts, and an expert warned against buying unlicensed weight-loss products online.
- Who
- Researchers from the University of Pennsylvania studied Reddit posts by people who claimed to use retatrutide.
- What
- The study identified 129 reported symptoms among users, including increased appetite, fatigue and nausea.
- When
- The study was published before the article appeared on October 14, 2026. The exact publication date is not stated.
- Where
- The researchers examined posts on Reddit. The study was published in JAMA Network Open.
- Why
- The researchers analyzed posts about reported symptoms. The study raised concerns about use of an unlicensed drug.
This story does not have two clearly opposing sides.
Researchers examined 148,640 Reddit posts related to retatrutide and narrowed them to 13,589 users who claimed to be taking the drug.
Researchers counted 7,823 users who reported at least one side effect and identified 129 reported symptoms.
The study was published in JAMA Network Open.
- Reddit posts examined
- 148,640
- Claimed users analyzed
- 13,589
- Users reporting at least one side effect
- 7,823
- Symptoms reported
- 129
- Most commonly reported symptom
- Increased appetite, reported by 1,336 users
What people are saying
I would urge people to avoid buying unlicensed weight-loss products online
There is no certainty about what these products contain, and without proper regulatory oversight there is a risk of adverse effects.