We’re still figuring out the side effects of GLP-1 weight-loss drugs
We’re still figuring out the side effects of GLP-1 weight-loss drugs
摘要: Biotechnology and health
We’re still figuring out the side effects of GLP-1 weight-loss drugs
Could the drugs affect hair, nails, and vision?
正文
Biotechnology and health
We’re still figuring out the side effects of GLP-1 weight-loss drugs
Could the drugs affect hair, nails, and vision?
Jessica Hamzelou
archive page
October 9, 2026
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EXECUTIVE SUMMARY
This week my colleague Antonio Regalado had an interesting update on GLP-1 weight-loss drugs. According to research presented at an aging meeting in Boston, these drugs seem to affect at least some measures of
biological age
.
Overweight and diabetic people who take GLP-1s
have a biological age around two to three years younger
than similar individuals who take a placebo, according to findings from Eli Lilly and Novo Nordisk, two pharmaceutical companies that make the drugs.
I’ve heard people in the aging field describe GLP-1s as longevity drugs for a while now (even if they only benefit people who are overweight or diabetic in the first place). This latest announcement comes after we’ve seen a raft of other benefits associated with taking these drugs. But there are also some weird side effects.
So far, GLP-1 agonist drugs—which repress hunger—have been approved for treating diabetes, chronic kidney disease, and obesity, and they can also be prescribed for some people who are overweight or at risk of certain cardiovascular diseases. But there is research to suggest they might also help people with substance-use disorders, and they’ve been investigated for potential benefits
in neurodegenerative disease and cancer
.
of people are taking them. According to
a recent Gallup poll
, 11% of Americans are taking a GLP-1 drug for weight loss, up from 3% in 2024. And 15% of Americans say they’ve used one for weight loss at some point.
They can be incredibly effective. But, like any drug, they can come with side effects. And we’re still figuring out exactly what those might be, and how widespread they are.
The most common side effects are gastrointestinal—nausea, vomiting, diarrhea, and constipation. The drugs have also been