Statins are a type of prescription drug that lower total cholesterol and reduce the risk of stroke or heart attack for people with high cholesterol.

As with many medications, statins may cause side effects, including digestive problems, muscle pain and weakness, and cognitive dysfunction. Another side effect that’s been linked to statins is weight gain.

Do statins cause weight gain? 

A 2014 study of almost 28,000 U.S. adults compared people who didn’t take statins and people who did take statins over an 11-year period. People who didn’t take statins didn’t change their eating habits or gain significant weight. People who did take statins consumed more calories and fat over time, and gained more weight. 

The study also showed that statin users had a faster increase in body mass index (BMI) than those who didn’t use statins.

There are a couple explanations that may be at play:

  • Behavioral. Some people who take statins may place less emphasis on their diet since the medication is doing the work of lowering their cholesterol. 
  • Physical. A potential side effect of statins is muscle pain and weakness. If people are experiencing this side effect, they may be less likely to exercise, which could result in weight gain. 

Other side effects of statins 

Potential side effects from statins include:

  • Muscle pain and damage. Fatigue, soreness, or weakness can range from mild to interfering with daily activities. According to the Mayo Clinic, the risk of muscle pain from taking statins is about 5%. The Mayo Clinic indicates there’s a very low risk of life threatening muscle damage (rhabdomyolysis). This risk occurs in a few cases per million people, and typically only affects people taking high doses of statins or statins in combination with specific drugs.
  • Increased blood sugar or type 2 diabetes. When you take a statin, it’s possible your blood sugar level may increase. This, in turn, may lead to type 2 diabetes. The Food and Drug Administration (FDA) indicates that the increased risk is small and outweighed by the statin’s benefits of reducing heart attacks and strokes.
  • Liver damage. Your doctor may recommend a liver enzyme test before or soon after you start taking a statin. Sometimes, taking a statin can result in an increase in enzyme levels, signaling liver inflammation. Call your doctor if you notice symptoms of liver damage, such as yellowing of the eyes and skin, dark-colored urine, or pain in your upper abdomen.
  • Neurological side effects. According to the Mayo Clinic, while some statin users have reported confusion and memory loss, clinical research hasn’t confirmed this to be a problem. In fact, the Mayo Clinic notes that some research suggests that statins could potentially prevent confusion and memory loss.

How do statins work? 

Having too much cholesterol in your blood increases your risk of having a heart attack or stroke. Statins block hydroxy-methylglutaryl-coenzyme A reductase, an enzyme in your liver that makes cholesterol. Blocking this enzyme reduces the amount of cholesterol your liver makes. Statins also help the liver remove cholesterol that’s already in your bloodstream. 

Statins include:

Takeaway  

The use of statins may be connected to weight gain, but there’s no clinical evidence as to why this weight gain occurs. The connection may be behavioral (people thinking that taking a statin balances overeating) or physical (if statins cause muscle pain and weakness, then people taking a statin may not get enough exercise). 

If you’ve been prescribed statins and think you might be having side effects from them, talk with your doctor. They may be able to recommend a change, like adjusting your dosage or trying a different type of medication.