Hydration matters more on GLP-1 medication than you might think. When you're eating less, you're getting less water from food. GI side effects can deplete fluids further. And dehydration can make side effects worse, sap your energy, and stall results.
Here's everything you need to know about staying properly hydrated.
Why Hydration Matters More Now
Less Water from Food
About 20% of our water intake typically comes from food. When you're eating significantly less, that water source shrinks. You need to make it up through drinking.
GI Side Effects
Nausea, vomiting, and diarrhea all deplete fluids. If you're experiencing these common early side effects, your hydration needs increase.
Metabolism and Fat Processing
Your body needs water to metabolize fat and flush out byproducts of weight loss. Dehydration can actually slow the process.
Energy and Wellbeing
Many symptoms people attribute to the medication—fatigue, headaches, dizziness, constipation—are actually dehydration in disguise.
How Much Do You Need?
A common target is 64 ounces (8 cups) daily, but on GLP-1 medication, aim higher:
Target: 80-100+ ounces daily (10-12+ cups). More if you're active, in hot weather, or experiencing GI symptoms.
That sounds like a lot. Here's how to think about it:
- 20 oz when you wake up
- 20 oz mid-morning
- 20 oz at lunch
- 20 oz mid-afternoon
- 20 oz at dinner
That's 100 oz across your waking hours—totally doable when broken down.
Signs You're Not Getting Enough
- Urine color: Should be pale yellow. Dark yellow = drink more.
- Headaches: Often the first sign of dehydration
- Fatigue: Feeling tired despite adequate sleep
- Dizziness: Especially when standing up
- Constipation: Hard, infrequent stools
- Dry mouth/skin: Obvious but often ignored
- Decreased urination: Going less often than usual
Practical Tips That Work
Make It Easy
- Keep a large water bottle with you always
- Use a bottle with measurements to track intake
- Set phone reminders to drink
- Link drinking to habits (every time you check email, drink)
Make It Appealing
- Add lemon, lime, cucumber, or mint for flavor
- Try herbal tea (hot or iced)
- Use water enhancers if needed (watch for artificial sweeteners)
- Find your preferred temperature—some people drink more ice cold, others room temp
Spread It Out
- Sip throughout the day rather than chugging
- Front-load earlier in the day to avoid nighttime bathroom trips
- Don't try to catch up all at once—your body can only absorb so much
What Counts as Hydration?
Yes, These Count
- Water (obviously)
- Herbal tea
- Sparkling water
- Decaf coffee and tea
- Broth-based soups
- Water-rich fruits (watermelon, cucumber)
Partially Count
- Coffee and caffeinated tea (mild diuretic effect)
- Milk and milk alternatives
- Juice (high in sugar—limit)
Don't Count
- Alcohol (actually dehydrates)
- Sugary sodas (empty calories, often dehydrating)
Electrolytes: When You Need Them
If you're experiencing vomiting, diarrhea, or heavy sweating, plain water may not be enough. You're losing electrolytes (sodium, potassium, magnesium) that water alone doesn't replace.
Consider:
- Low-sugar electrolyte drinks (Liquid IV, LMNT, Nuun)
- Coconut water
- Broth (especially bone broth)
- Electrolyte tablets added to water
Warning signs of electrolyte imbalance: Muscle cramps, heart palpitations, confusion, severe fatigue. If you experience these, contact your provider.
Timing Around Meals
Some tips for drinking around your smaller meals:
- Don't drink large amounts with meals—it can increase fullness too much and potentially worsen nausea. Sip, don't gulp.
- Hydrate between meals—do most of your drinking away from food.
- Wait 30 minutes after eating before drinking larger amounts if you tend toward nausea.
Common Mistakes
- Waiting until you're thirsty: By then you're already mildly dehydrated
- Relying on coffee: It has a mild diuretic effect—don't count it fully
- Stopping fluids early: Some people stop drinking after 6pm to avoid bathroom trips, then wake up dehydrated
- Forgetting on busy days: These are often when you need it most
The Bottom Line
Proper hydration is one of the simplest things you can do to feel better, reduce side effects, and support your results on GLP-1 medication. It requires zero willpower—just a water bottle and some awareness.
Make it a priority from day one. Your body will thank you.