Science Explains Why Ozempic Can Make You Constipated

To say that Ozempic (semaglutide) has revolutionized the treatment of obesity and type 2 diabetes is, if anything, an understatement. Ozempic was initially developed by Novo Nordisk for the main purpose of managing type 2 diabetes. However, Ozempic's striking effects on weight loss has made it an enormously popular off-label treatment for obesity ("off-label" because obesity is not an approved use of Ozempic by the FDA). 

Along with the weight-loss benefits of Ozempic are potential side effects, such as constipation. It turns out that the very effects of Ozempic that are responsible for weight loss (slowing down of stomach emptying and reduced gut motility) may also cause constipation. According to the Ozempic label (also known as the prescribing information), 5% of patients with type 2 diabetes who were taking a 0.5-mg dose of Ozempic experienced constipation, while 3% of patients taking a 1-mg dose had constipation. Other studies have shown much higher constipation rates (as high as 37%) in people taking Ozempic. Another important fact is that constipation lasts longer than other gastrointestinal side effects of Ozempic, hanging around for an average of 47 days in one study.

More generally, Ozempic belongs to a class of antidiabetic drugs known as glucagon-like peptide-1 (GLP-1) receptor agonists. These drugs work by binding to GLP-1 receptors in the body, which promotes the release of insulin from the pancreas, with insulin being a hormone that converts glucose into glycogen, thus reducing the amount of glucose in the blood. This important hormone is responsible for glucose homeostasis in the body. GLP-1 agonists also reduce the release of glucagon, which has the opposite effect to that of insulin. By reducing glucagon, GLP-1 agonist like Ozempic further lower glucose levels. 

The gastrointestinal side effects of Ozempic, the "Ozempic poops" phenomenon, is easily explained by science – but it's not the only one. Besides reducing glucose levels in the blood, Ozempic can slow down the digestive system and can cause constipation by several mechanisms. One mechanism is through delayed stomach emptying. By slowing down the rate at which the stomach empties food into the small intestine, Ozempic causes people to feel fuller and therefore eat less. However, it can also mean that they take in less liquid and less fiber, resulting in harder stools and more constipation. Slowing down digestion also causes reduced intestinal motility. Reduced muscle contractions in the gut wall means that food takes longer to move through the digestive system and be excreted as poop. The silver lining is that symptoms of constipation are more common when people first start taking Ozempic and tend to lessen after the first month of treatment. Other complications include a number of long-term (and little discussed) side effects of Ozempic.

In up to 1 in 20 people who have diabetes or obesity and are newly treated with Ozempic, a more severe condition called stomach paralysis (gastroparesis) may occur. In stomach paralysis, whole pieces of food remain in the stomach for a longer time and, in some cases, may harden into solids, causing nausea, vomiting, and even death. The reduced absorption of nutrients and fluids from food can also cause malnutrition and dehydration. 

Although constipation can be uncomfortable and disruptive, there are several measures and medications that can manage it. To help reduce symptoms of constipation while taking Ozempic, make sure to consume enough fiber, drink a lot of water (11 to 16 cups of water per day is ideal), and increase physical activity. Going to the bathroom at a regular time every day may also help counteract constipation. If these measures aren't helping enough, taking probiotics or laxatives such as polyethylene glycol (Miralax), bisacodyl (Dulcolax), and docusate sodium (Colace) can help move things along. 

Just like any medication, it's a good idea to consult your doctor before taking any laxative to make sure that it doesn't interact with Ozempic or other current medications. In addition, talk with your healthcare professional and let them know about your constipation symptoms. They may decide to lower the dose of Ozempic, depending on the severity of the constipation and how much it is disrupting your life.