How To Manage the Digestive Side Effects of GLP-1 Medications

When you start taking a GLP-1 medication for weight loss, some effects kick in quickly, like feeling less hungry and experiencing less “food noise” than before. But it can take your body some time to adjust — and in the meantime, digestive side effects are common.

“The most common side effects of GLP-1 medications are all gastrointestinal: reflux, diarrhea, constipation and nausea, sometimes to the point of vomiting,” says endocrinologist and obesity medicine specialist Keren Zhou, MD.

If you’re experiencing unpleasant digestive side effects while taking a GLP-1, these strategies may help.

Tips for managing GLP-1 side effects

GLP-1 medications sometimes cause digestive problems because of the way they help you lose weight. It all comes down to how food moves through the digestive process, also known as gut motility.

“GLP-1 medications literally slow down how quickly your stomach empties out,” Dr. Zhou explains. “That means that what you eat, how much you eat and how quickly you eat it can all play a big role in how you feel.”

Here’s what Dr. Zhou recommends.

1. Don’t take your medication after a big meal

In the beginning — whether it’s your very first dose or your first increased dosage — Dr. Zhou recommends taking your GLP-1 medication on a not-too-full stomach.

“I typically recommend eating lighter in the 24 hours before you take your first GLP-1 shot,” Dr. Zhou advises. “Because the minute the medication goes in and slows everything down, you may end up feeling sick.”

That doesn’t mean skipping meals. Eating lighter means avoiding foods that may trigger symptoms (more on that in a moment). That includes anything that is:

• High in fat
• Greasy
• Sugary

“Don’t try to eat a ‘last hurrah’ meal before you start,” she cautions.

2. Eat smaller meals

When you’re on a GLP-1, anticipate needing to eat smaller meals than before. Now that your stomach doesn’t empty as quickly, it just doesn’t have the same capacity it used to. That helps with weight loss — but it can also make for some uncomfortable post-meal feelings, especially in the beginning.

“If you try to eat a big meal on a GLP-1, you’ll quickly find out that it doesn’t really fit,” Dr. Zhou says. “Eating too much can cause you to feel pretty nauseated, and it can bring on a lot of reflux.”

Eating smaller but more frequent meals gives your stomach more time to digest in between, which can help keep digestive issues at bay. Think of it as giving your stomach a little breathing room between meals.

3. Slow down

Pacing yourself throughout a meal — like by practicing mindful eating — can keep you from consuming so much that you bring on uncomfortable digestive symptoms.

But why? The faster you eat, the more you’re likely to eat. It all comes down to the connections between your body and mind. It can take your brain up to 30 minutes after eating to recognize that you’re full.

That means that as you’re eating, you can’t always tell when you’ve had enough. And when your stomach has a newly reduced capacity, it can take extra time for your body and brain to make that adjustment.

4. Limit foods that set off your symptoms

Some foods are known to worsen the side effects of GLP-1s. Not every food on this list will trigger every person who takes a GLP-1, but it can take some time to figure out what affects you.

“Many people who are on GLP-1s tell me that they know when they haven’t eaten well on the medication because their body reminds them,” Dr. Zhou shares. “You end up paying the price in terms of how you feel afterward.”

Try to limit or avoid:

• Sugary foods and drinks, like juice, soda, candy and desserts
• Refined carbohydrates, like white bread, pasta and white rice
• Ultra-processed foods, like packaged snacks
• High-fat foods, like pizza and fried chicken
• Spicy foods, like hot sauce and chili peppers

5. Stay hydrated

Hydration is an essential part of the digestive process. It literally keeps things moving, making sure that your stool (poop) stays soft and mobile enough to make its way out of your body. But Dr. Zhou issues a word of warning about GLP-1s and dehydration.

“When you’re less driven to eat, you sometimes lose the drive to drink water, too,” she warns. “Sometimes, when people who take these medications aren’t feeling great, it turns out that they’ve forgotten to hydrate.”

Diarrhea can also cause dehydration. And dehydration can, in turn, cause or worsen constipation. In other words? It’s all connected — and staying hydrated helps you stay healthy.

If drinking water during mealtimes makes you feel full (which can keep you from eating enough), sip water throughout the day and between meals. It can help to set reminders and alarms to make sure you don’t forget.

6. Be mindful of fiber

Foods that contain fiber can help prevent or relieve constipation by adding bulk to stool and supporting healthy digestion. But timing matters.

If you’re already feeling bloating, fullness or GI (gastrointestinal) discomfort after taking your GLP-1 medication, upping your fiber intake may be a little too much for you to handle. It can make symptoms worse, especially if you eat more fiber than your body is used to.

“It’s often best to take it easy on high-fiber foods immediately after taking your GLP-1 medication,” Dr. Zhou advises.

7. Manage symptoms as they arise

Despite your best efforts to prevent side effects, there are days when you may still end up with tummy troubles. That can be especially tough amid the hustle and bustle of everyday life. Who has time for mid-workday diarrhea?!

If your symptoms are severe or don’t seem to be going away, make an appointment with your healthcare provider ASAP. Otherwise, Dr. Zhou says you can take steps to manage GLP-1-related digestive issues as they come up. Here’s what to try.

If you have nausea…

• Sip on tea. Ginger tea or peppermint tea may help ease an upset stomach. Just don’t add sweeteners, which can make things worse.
• Sit up. Stay upright for 30 minutes after eating to let gravity work its magic. Lying down can intensify GLP-1-related nausea.
• Ask about anti-nausea meds. Some people experience nausea regularly after taking their GLP-1 medication. Your provider may prescribe something like ondansetron (Zofran®) to keep on hand for relief in the short term.

If you have constipation…

• Drink water. Hydrate to help soften stool and get your digestive system in motion.
• Use a footstool when you poop. This puts your body in a position that makes it easier to poop.
• Go for a walk. Physical activity helps get your gut moving. Even a few minutes of movement can do the trick.
• Ask about over-the-counter (OTC) medications. Your healthcare provider may recommend stool softeners, laxatives or other options for temporary relief.

If you have diarrhea…

• Hydrate with electrolytes. Diarrhea can dehydrate you and throw off your electrolyte balance, so replenish with water and good sources of electrolytes.
• Eat gentle foods. Foods that are soft, bland and low in fiber can help calm your gut and aren’t likely to make diarrhea worse.
• Skip certain drinks. In addition to avoiding trigger foods, it’s best to limit or avoid caffeine, alcohol and dairy-based beverages when you have diarrhea.
• Discuss anti-diarrheal medications. Your provider may suggest a short-term OTC option, like loperamide (Imodium®, Maalox Anti-Diarrheal®) or bismuth subsalicylate (Pepto-Bismol®, Kaopectate®).

8. Talk to your provider

Digestive side effects can be a normal part of starting a GLP-1. But don’t just assume that nothing can be done to help.

“As with any medication, your doctor wants to be closely following how you’re feeling,” Dr. Zhou encourages. “So, if you’re on a GLP-1 and you don’t feel like you’re doing well, that’s something they want to know about.”

That doesn’t mean you’ll have to stop the medication. Your provider may recommend changes like:

• Other management strategies: They’ll want to know what you’ve tried and may be able to recommend additional options. “There’s a lot we can do to help you manage these side effects,” Dr. Zhou says.
• A different dosage: When you begin a GLP-1, your provider will start you on a low dose that increases with time (“titrating up”). But if you’re having side effects, they may want to adjust your dosage at a slower pace.
• Trying a new GLP-1: There are a few GLP-1 medications out there, and they may affect you in different ways. If you’re struggling with side effects on one, your provider may recommend switching to another.

9. Give it time

When you’re in the thick of digestive issues, “Wait it out” is tough advice to follow. But Dr. Zhou says that GLP-1 side effects lessen and fade with time for most people.

“We think the body does adapt around the medication, to some extent,” she shares. “We often see that people experience their most significant side effects during the first three to four weeks on a GLP-1, when delayed stomach emptying is at its worst.”

But if side effects become severe, don’t try to power through them alone. Your healthcare provider may be able to adjust your treatment plan, recommend symptom-management strategies or determine whether another approach is a better fit.

What if side effects don’t go away?

It’s not common, but there are times when the digestive side effects of a GLP-1 make the medication too much to handle.

“There’s a small group of people for whom these side effects are so severe that they’re just, frankly, intolerable,” Dr. Zhou says. “In these cases, there’s no waiting it out. It’s just not the right medication for them.”

But this isn’t usually the case.

“More often than not, we’re able to get people to a place where they’re doing OK and continue the medication,” she continues. “For most people, strategies like eating smaller meals, hydrating and avoiding trigger foods can all go a long way toward making treatment more tolerable.”