Top side effects of GLP-1s
They don’t happen to everyone, but GLP-1s can come with unpleasant side effects like nausea and constipation. Here’s what to expect — and how to feel better.
The conversations about GLP-1s tend to focus on the results — losing weight, cutting food noise, and reducing health risks. And while those are all true, an important part of the conversation is often missing: the uncomfortable, unpleasant side effects these weight-loss medications may cause. While they don’t happen to everyone, here are some of GLP-1’s potential side effects, and more importantly, how you can make them less severe, so the benefits of the medication don’t feel like such a trade-off.
Most common side effects
Most often, the side effects for GLP-1s tend to be focused on the gastrointestinal system, where these medications work by changing gut hormones.
Nausea is the most common side effect, impacting up to 50% of people who take a GLP-1. Other common G.I. side effects include constipation, diarrhea, abdominal discomfort, and bloating. Research indicates these effects could result from slower stomach emptying.
But there’s a plus side: These side effects tend to be mild and don’t last very long, according to Dr. Sarah Fishman, M.D., a professor of medicine, endocrinology, diabetes, and bone disease at Icahn School of Medicine at Mount Sinai in New York City. They usually happen when you first begin taking the drugs, a period when you are steadily increasing your dosage. As a result, “they usually resolve within a few days of the injection, and within a few weeks of longer-term use,” says Fishman.
Less common side effects
While not likely — the risk is less than 2% — some people taking a GLP-1 experience gallstones, which are small, rock-like deposits of hardened digestive fluid. This is likely because GLP-1 agonists can delay the emptying of bile from the gallbladder.
“If a person has more severe obesity and loses weight very, very quickly, there's a possibility that the rapid weight loss may cause them to have gallstones,” says Dr. Peter Vash, M.D., an endocrinologist and obesity medicine specialist based in Los Angeles. Losing at a rate of more than 3.3 pounds a week is when you can start to see the gallstone risk go up, which can then contribute to pancreatitis, or inflammation of the pancreas that can lead to complications if left untreated. However, Vash says, “that's a very rare side effect.”
And if you’ve heard that GLP-1s can increase your risk of thyroid cancer, you don’t necessarily need to be alarmed. “There is a theoretical increased risk of medullary thyroid cancers, but it’s not clear how likely this is to actually happen in people,” says Fishman, who along with Vash stresses that the link has only ever been studied in animals.
How to manage GLP-1 side effects
Many common side effects from weight loss medications will subside over time as your body adjusts, but in the meantime, you can help ease many of them. Here’s how:
Nauseaand vomiting: Try ginger tea, a natural remedy. Or ask your doctor about a prescription medication like ondansetron, which is often used to control nausea and vomiting, until your body adjusts.
Constipation: Get things moving again by drinking more water, adding a fiber supplement (like Metamucil), or using a gentle osmotic laxative.
Diarrhea: Make sure your diet is limiting foods high in sugar and fat, drink lots of water, and avoid dairy products and high-fiber foods; you can also take loperamide (Imodium).