Signs of dehydration on GLP-1, and what to do

Why the risk goes up during treatment

With less appetite, meals get smaller, and food is part of each day’s water. Drinking often drops along with it.

When vomiting or diarrhea comes up, the body loses fluid and salt faster than thirst can warn you. The prescribing information for GLP-1 agonists, such as semaglutide (Ozempic, Wegovy), tirzepatide (Mounjaro) and liraglutide (Saxenda), notes that, in these cases, dehydration can end up affecting the kidneys.

The signs

The most common ones, and the ones that tend to show up first:

• Dry mouth and strong thirst.
• Dark urine, or little urine over the day.
• Dizziness when you stand up.
• Unusual tiredness.

What to do

When the signs are mild, you can start at home:

• Drink water in small, frequent sips throughout the day, instead of a big glass all at once.
• With vomiting or diarrhea, oral rehydration solution also replaces salts.
• When dizziness comes on, sit or lie down until it passes. To get up, sit on the edge of the bed for a moment before standing.
• If it’s been a while since your last meal, eat something light.
• Don’t drive while the dizziness is there.

Before any water or rehydration solution

If you have heart failure or kidney disease (including if you’re on dialysis), or your care team has given you a fluid or salt limit, follow that limit, not a general water goal. In these cases, oral rehydration solution is only with your care team’s guidance.

Check with the people who care for you before trying homemade rehydration drinks, teas or supplements: some interact with medications or are hard on the kidneys or the heart.

If you take other medications

If you take a diuretic or a blood pressure or diabetes medication, let your care team know the same day vomiting or diarrhea starts, even without signs of dehydration. These medications need extra care when you’re losing fluid, and any change to them is your care team’s decision.