About statins

Simvastatin (Zocor) and atorvastatin (Lipitor) are two types of statins that your doctor may prescribe for you. Statins are often prescribed to help lower your cholesterol. According to the American College of Cardiology, statins can help if you:

  • have a buildup of cholesterol in your blood vessels
  • have an LDL, also known as bad cholesterol, level greater than 190 milligrams per deciliter (mg/dL)
  • have diabetes, are between 40 and 75 years old, and have LDL level between 70 and 189 mg/dL, even without buildup of cholesterol in your blood vessels
  • have LDL between 70 mg/dL and 189 mg/dL, are between 40 years old and 75 years old, and have at least a 7.5 percent risk that cholesterol could build up in your blood vessels

These drugs are similar, with small differences. See how they stack up.

Both simvastatin and atorvastatin can cause various adverse effects. Some side effects are more likely to occur with simvastatin, and others are more likely with atorvastatin.

Muscle pain

All statins can cause muscle pain, but this effect is more likely with simvastatin use. Muscle pain may develop gradually. It can feel like a pulled muscle or fatigue from exercise. Call your doctor about any new pain you have when you start taking a statin, especially simvastatin. Muscle pain can be a sign of developing kidney problems or damage.


A side effect that can occur with either drug is fatigue. A study funded by the National Institutes of Health (NIH) compared fatigue in patients who took small doses of simvastatin and another medication called pravastatin. Women, especially, have a substantial risk of fatigue from statins, although more so from simvastatin.

Upset stomach and diarrhea

Both drugs can cause stomach upset and diarrhea. These side effects usually resolve over the course of a few weeks.

Liver and kidney disease

If you have kidney disease, atorvastatin could be a good choice for you because there is no need to adjust the dosage. On the other hand, simvastatin can affect your kidneys when given at the highest dosage (80 mg per day). It may slow your kidneys. Simvastatin also builds up in your system over time. This means that if you take it for an extended period of time, the amount of the drug in your system can really add up. Your doctor might have to adjust your dosage.

However, based on results from a 2014 study by the American Heart Association, there is likely no increased risk of kidney injury between high-dose simvastatin and high-dose atorvastatin. What’s more, dosages of simvastatin as high as 80 mg per day are no longer very common.

A few people who take statins develop liver disease. If you have darkened urine or pain in your side while taking either drug, call your doctor immediately.


A high dosage of atorvastatin (80 mg per day) is associated with a higher risk of hemorrhagic stroke if you’ve had an ischemic stroke or a transient ischemic attack (TIA, sometimes called a mini stroke), in the last six months.

High blood sugar and diabetes

Both simvastatin and atorvastatin can increase your blood sugar and your risk of developing diabetes. All statins may increase your hemoglobin A1C level, which is a measure of long-term blood sugar levels.

Learn more: Statins and diabetes risk »

Although grapefruit is not a drug, doctors recommend that you avoid consuming large amounts of grapefruit or grapefruit juice if you take statins. That’s because a chemical in grapefruit can interfere with the breakdown of some statins in your body. This may increase the level of statins in your blood and increase your chance of adverse effects.

Both simvastatin and atorvastatin can interact with other drugs. You can find detailed lists of their interactions in the Healthline articles on simvastatin and atorvastatin. Notably, atorvastatin may interact with birth control pills.

Both simvastatin and atorvastatin are film-coated tablets that you take by mouth, usually once per day. Simvastatin comes under the name Zocor, while Lipitor is the brand name for atorvastatin. Each is available as a generic product, as well. You can buy either drug in most pharmacies with a prescription from your doctor.

The drugs are available in the following strengths:

  • Simvastatin: 5 mg, 10 mg, 20 mg, 40 mg, and 80 mg
  • Atorvastatin: 10 mg, 20 mg, 40 mg, and 80 mg

The costs of generic simvastatin and atorvastatin are both fairly low, with generic simvastatin being slightly less expensive. It comes in at about $10–15 per month. Atorvastatin is usually $25–40 per month.

The brand-name drugs are much more expensive than their generics. Zocor, the brand for simvastatin, is about $200–250 per month. Lipitor, the brand for atorvastatin, is usually $150–200 per month.

So if you’re buying the generic, simvastatin is cheaper. But when it comes to the brand-name versions, atorvastatin is less expensive.

Your doctor will consider many factors when recommending treatment with a statin such as simvastatin and atorvastatin. Often, choosing the right drug is less about comparing the drugs to each other and more about matching the possible interactions and side effects of each drug with your individual medical history and the other drugs you take.

If you currently take simvastatin or atorvastatin, ask your doctor the following questions:

  • Why am I taking this drug?
  • How well is this drug working for me?

If you’re having side effects like muscle pain or dark urine, talk to your doctor right away. However, don’t stop taking your statin without talking to your doctor. Statins only work if they are taken every day.