Does Ozempic cause blood clots?

In this article:

• Does Ozempic cause blood clots?
• Why does Ozempic cause blood clots?
• How to prevent Ozempic blood clots
• Other Ozempic side effects
• When to see your healthcare provider about Ozempic blood clots

In this article

• Does Ozempic cause blood clots?
• Why does Ozempic cause blood clots?
• How to prevent Ozempic blood clots
• Other Ozempic side effects
• When to see your healthcare provider about Ozempic blood clots

Intended for people with Type 2 diabetes, Ozempic (semaglutide) is an injectable medication that can help lower blood sugar, reduce the risk of cardiovascular disease and heart attack, and suppress appetite to help with weight loss. It belongs to a class of drugs called glucagon-like peptide 1 (GLP-1) receptor agonists.

Though Ozempic is considered safe, it can still cause side effects, particularly gastrointestinal side effects like nausea and diarrhea. But there’s also a possible link between Ozempic and blood clots. Here’s what you should know and how to reduce any risk. 

Does Ozempic cause blood clots?

Ozempic’s manufacturer, Novo Nordisk, does not report blood clots as a side effect. “There is not enough evidence to say that semaglutide definitely causes blood clots,” says Jodie Pepin, Pharm.D., clinical pharmacy program director at Harbor Health. Additionally, the Food and Drug Administration (FDA) prescribing information for Ozempic does not mention blood clots as a possible adverse reaction. 

So, why the concern? A 2021 meta-analysis of the SUSTAIN and PIONEER trials—the clinical trial programs used to assess semaglutide’s effectiveness in people with Type 2 diabetes—found that semaglutide use increased deep vein thrombosis (DVT) by 266%. DVTs are blood clots in the deep veins of the body, oftentimes in the legs.

“Recent clinical studies such as PIONEER and SUSTAIN analysis have shown extremely high rates of blood clots in patients with diabetes,” says Raj Singh, MD, a primary care provider at HEALOR and medical director at RAREV Medical Spa in Las Vegas, Nevada. “The exact mechanisms are not known at this time, and further research is needed.”

“Indeed, more research is needed,” agrees Dr. Pepin. She explains that the SUSTAIN and PIONEER trials were designed to determine the effectiveness of semaglutide, not the drug’s safety profile. Although an increase in blood clots was reported, researchers did not investigate whether Ozempic caused any of the blood clots. “The concerns that arose in the meta-analysis caused a desire to study this topic deeper,” she says, adding that the Food and Drug Administration (FDA) is currently investigating several safety concerns with semaglutide and has added blood clots to the investigation.

Why does Ozempic cause blood clots?

While it is still not known whether Ozempic directly causes blood clots, there are some possible reasons people taking this drug might be more prone to DVT. The most likely cause of blood clots on Ozempic is related to why most people are on this drug to begin with: Type 2 diabetes.

“Diabetes is considered a mother of all diseases,” Dr. Singh says. “Patients with diabetes have many other associated comorbid conditions such as limited mobility, increased risk of infections, heart failure, lung problems, and chronic kidney disease. All these conditions are associated with [increasing the] risk of blood clots.”

Other conditions that increase the risk of blood clots and frequently co-occur with Type 2 diabetes include obesity, high blood pressure, high cholesterol (high LDL), and atherosclerosis, according to Dr. Pepin. 

Another possible link between Ozempic and blood clots is dehydration. Dr. Singh points out that diarrhea, a very common Ozempic side effect, can lead to dehydration. When the body is dehydrated, the resulting thickened blood can raise the risk of blood clots, according to the American Heart Association.  

Finally, there’s the reduced stomach acid production linked to Ozempic, which might lead to reduced vitamin absorption, according to Dr. Singh. “Lower levels of B12 are associated with increased homocysteine levels, which increases [the] risk of blood clot formation,” he explains. 

The bottom line is this: While there is no evidence to prove that Ozempic causes blood clots, the people prescribed this medication—people with type 2 diabetes, primarily—likely have a higher-than-average risk of blood clots. Not only that, but the gastrointestinal side effects of Ozempic may indirectly contribute to a heightened risk of blood clot formation.

How to prevent Ozempic blood clots

The tactics for preventing blood clots on Ozempic are the same as those for the general population: hydration and movement, primarily. 

Hydration and a healthy diet

Staying hydrated can help with the gastrointestinal effects of semaglutide and may also indirectly lower the risk of blood clots. Drs. Pepin and Singh both recommend drinking plenty of fluids while on this medication.

Water isn’t the only hydrating beverage. Low-sugar electrolyte drinks help replenish essential minerals lost through diarrhea. If diarrhea is an issue, Dr. Pepin suggests adding more fiber to your diet. Soluble fiber, which is found in fruits, vegetables, whole grains, and over-the-counter supplements such as psyllium fiber, helps soak up intestinal water and create bulk in the digestive tract.

“Usually, the GI side effects of GLP-1s can be decreased by eating a healthy diet full of vegetables and fruit, healthy grains, and protein,” Dr. Pepin says. “High-sugar and high-fat food, and a high volume of food, make GI side effects worse.”

Exercise

Regular movement is also crucial because it helps circulation. In addition to exercising more, Dr. Singh suggests avoiding sitting for prolonged periods. This might mean scheduling regular stretch breaks throughout the workday or avoiding long flights if you have any risk factors associated with blood clots: obesity, high blood pressure, or high cholesterol. “The good news,” Dr. Pepin says, “is that patients are more likely to exercise as they lose weight on Ozempic. This can decrease the incidence of blood clot formation.” 

Supplements and other medications

There are no supplements that will prevent blood clots, but Dr. Singh says it might be a good idea to start vitamin B-12 supplementation while on Ozempic. If a B-12 deficiency is to blame for blood clots on Ozempic, this could help prevent an adverse event.

Some people might think a reduced Ozempic dosage would reduce the risk of blood clots, but Dr. Pepin says that’s not necessarily true. “There is no evidence that blood clots are associated with higher doses of semaglutide,” she explains.

There are many alternatives to Ozempic that don’t include blood clots as a side effect, but remember, blood clots are not a proven side effect of Ozempic either. Other GLP-1 injectable drugs include Mounjaro, Trulicity, and Saxenda. Wegovy (semaglutide), an injection that is FDA approved for weight loss rather than managing blood sugar levels, contains the same active ingredient as Ozempic. Rybelsus also contains semaglutide as an active ingredient but in oral rather than injectable form. Finally, research suggests that metformin, an oral diabetes medication, may actually reduce the risk of deep vein thrombosis in patients with diabetes.

RELATED: Ozempic vs. metformin

If you are concerned about blood clots on Ozempic, the best thing you can do is seek personalized advice from a healthcare professional. 

Other Ozempic side effects

Blood clots are not a proven side effect of Ozempic. However, there are several common side effects caused by Ozempic and other GLP-1 receptor agonists. 

Common Ozempic side effects include:

• Weight loss
• Gastrointestinal symptoms, such as nausea, constipation, diarrhea, and abdominal pain
• Eye symptoms, such as diabetic retinopathy
• Low blood sugar, characterized by lightheadedness
• Injection site reactions, such as pain or redness

Serious side effects include:

• Thyroid tumors 
• Angioedema (swelling of tissues in the face, eyes, and lips)
• Acute kidney injury
• Worsening of kidney disease
• Pancreatitis (inflammation of the pancreas)
• Gallbladder inflammation (cholecystitis)
• Cholelithiasis (gallstones)
• Gastroparesis (stomach paralysis)
• Syncope (fainting and loss of consciousness) 

Serious side effects should be reported to a healthcare provider immediately. Seek emergency medical attention if there are signs of a severe allergic reaction to Ozempic, such as trouble breathing, rapid heart rate, shortness of breath, or dizziness.

When to see your healthcare provider about Ozempic blood clots

People taking Ozempic who experience symptoms of a blood clot should seek medical advice from a healthcare provider immediately. Symptoms of blood clots in the arms and legs include:

• Localized swelling 
• Painful throbbing
• Skin color changes (redness over the site or lack of color in the extremity)
• Temperature changes (localized warmth or a cold, clammy feeling)

Regardless of the cause, blood clots usually require a medical diagnosis and treatment. DVT, which happens when a clot forms in a deep vein, can cause a life-threatening pulmonary embolism. Anyone who suspects a blood clot should seek urgent medical attention. Tell the attending healthcare provider about all your medical conditions, supplements, and medications, including Ozempic.