FDA Adds New Side Effect Warnings to GLP-1 Drug Leaflets in the U.S.

Expert insight:

“These are not subtle warnings buried in fine print,” said Thomas Moore, a drug safety researcher at Johns Hopkins. “They’re featured in the Medication Guide to make sure patients and clinicians are paying attention.”

UK users: What about us?

The FDA’s update only affects the U.S., but it’s a strong signal to global regulators, including the UK’s MHRA and EMA in Europe. If you’re getting your GLP-1s privately in the UK, this kind of update won’t change what your clinic says, but it should change how seriously you take hydration.

Remember: These medications don’t just shrink your appetite; they also slow down digestion, which can increase nausea and make dehydration sneakier than it seems.

Source:

MedShadow, “FDA Adds Kidney Injury and Dehydration Risks to GLP-1 Drug Info,” July 22, 2025. Read the full article here.

What’s changed?

If you’re in the U.S., you’ll now see kidney injury and fluid loss warnings more clearly spelt out on the Medication Guide that comes with your prescription. These guides are separate from the prescriber info; they’re written in plain language for patients.

This includes:

Warnings about persistent vomiting and diarrhoea
The importance of staying hydrated
The potential for serious kidney damage if fluid loss isn’t addressed

Should you be worried?

Not necessarily, but this is a good reminder that side effects are real, and hydration matters more than you might think on GLP-1s.

If you’re experiencing ongoing nausea, vomiting, or diarrhoea, don’t ignore it. Not just because it’s miserable, but because it can impact your kidneys, especially if you’re already prone to kidney issues.

The U.S. Food and Drug Administration (FDA) has updated the official Medication Guides for GLP-1 drugs, including Ozempic, Wegovy, Mounjaro, and Zepbound, to add new warnings about acute kidney injury and dehydration-related complications.

These changes don’t mean the drugs are suddenly unsafe, but they do reflect increasing awareness of potential side effects, especially as more people worldwide start using GLP-1s for weight loss and diabetes.

The updated warnings specifically flag the risk of kidney damage following significant fluid loss, usually due to vomiting or diarrhoea, both common early side effects of GLP-1 medications.

In a statement, the FDA said the changes were made to ensure “patients and providers are aware of the potential for dehydration and its downstream risks.”

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