What makes statins life-saving?

Updated on 5 February 2026

While there have been concerns about statins, we now have ample evidence from large-scale trials to weigh the very small risk of side effects against their significant benefits.

Statins are one of the most commonly prescribed medicines and are truly life-saving. They’ve been shown to have a significant impact in reducing the risk of heart attacks, some types of strokes and other cardiovascular problems. Yet, questions continue to be raised about their safety, often fuelled by inaccurate information online and in the media.

Scientists at Oxford Population Health have painstakingly carried out clinical trials and detailed data analysis to better understand the risks and benefits of statin treatment. Their research has found that statins are highly effective at lowering cholesterol and are associated with very few side effects, which are experienced by only a small proportion of patients.

What are statins and how do they work?

Statins are a family of drugs that lower cholesterol – a fatty molecule that’s needed to keep our cells healthy, and is also involved in making vitamin D and some hormones. Although we hear a lot about cholesterol in fatty foods, most of the cholesterol found in the body is actually made by our livers. 

Research has shown that people with higher levels of certain types of cholesterol-containing molecules in the bloodstream (referred to as LDL, or so-called “bad” cholesterol) are more likely to develop hardening and narrowing of the arteries, known as atherosclerosis. They’re also at a higher risk of cardiovascular disease, including coronary heart disease, angina, strokes and heart attacks.

It has been known since the 1960s that high cholesterol in the bloodstream is a risk factor for heart disease. However, early clinical trials testing various techniques for lowering cholesterol – including drugs and changes to diet – failed to achieve significant changes in cholesterol levels.

In the 1980s, Oxford Population Health scientists Richard Peto and Rory Collins gathered together all the data from trials testing cholesterol-lowering interventions (a statistical technique known as a meta-analysis). They found that reducing cholesterol could cut the risk of cardiovascular problems, but that the approaches available at the time simply weren’t good enough. 

Then came statins. First developed in the 1970s from chemicals found in fungi, statins work by blocking the activity of a substance in the liver called HMG-CoA reductase that is involved in one of the first steps towards making cholesterol. Blocking its function cuts off cholesterol production at the source. There are now many different statins on the market, most of which are cheap and widely-available. 

How do we know that statins work and are safe?

The effectiveness and safety of statins have been tested in large-scale trials involving many thousands of patients over many years, several of which have been run by scientists at Oxford Population Health. Importantly, many of these studies are randomised, placebo-controlled trials, which are the best method we have of finding out how well a treatment works and the chances it could cause side effects. 

In 1994, Oxford Population Health researchers set up the Cholesterol Treatment Trialists’ (CTT) Collaboration. Over the years they have brought together and analysed data from over 30 large-scale trials, building a bigger, better analysis of the impact of statin treatment. They have also demonstrated that statins do not cause most of the possible side effects listed in package leaflets, and proved that there is no increased risk of cancer from taking the drugs. 

Overall, these large-scale randomised trials show that statins reduce the risk of heart attacks, strokes caused by blocked blood vessels (ischaemic strokes), and certain other cardiovascular problems. For example, a commonly prescribed statin such as atorvastatin, which costs as little as £2.50 a month in the UK and $10 in the US, will approximately halve someone’s LDL-cholesterol levels. The benefits don’t stop there.

As well as treating people with high cholesterol levels, statins can also help individuals who are at increased risk of cardiovascular disease for other reasons, such as having already suffered a heart attack, or having diabetes. They can prevent these kinds of events in around 1 in 10 patients with pre-existing cardiovascular problems over five years.

For people who are at increased risk of a stroke or heart attack but haven’t yet had one, the benefits are smaller but still add up to 500 cardiovascular events prevented per 10,000 people treated. 

That’s not to say that the other 9,500 people on statins will get no benefit from the drug at all. There is evidence to suggest that statins have a long-term impact on atherosclerosis (hardening of the arteries) for a larger number of people. Taking the drugs for ten years prevents more heart attacks and strokes than five years of medication. 

Clinical trials have also revealed things that don’t help. For example, for more than 30 years, a cheap and widely-available drug called niacin (also known as vitamin B3) was used in combination with or instead of statin therapy to manage high cholesterol. However, a large trial led by Oxford Population Health researchers showed that this combination wasn’t any more effective than statins alone, and increased the risk of side effects such as facial flushing, bleeding, type 2 diabetes and life-threatening infections. Following another trial in 2024, which found that prescription-level doses of niacin actually increased the risk for heart attack, stroke or death for some people, it is no longer a recommended treatment.

Balancing benefits and risks

The most recent study conducted by the CTT Collaboration gathered data from 23 large-scale randomised studies to undertake the most comprehensive review of possible side effects. They found that statins did not cause the majority of the conditions listed as possible side effects in their package leaflets, including memory and sleep problems, depression, erectile dysfunction, weight gain and many other conditions.

The study’s authors noted that adverse health outcomes listed as potential side effects were based largely on non-randomised trials that could be subject to bias. They recommended that information be revised to help patients and doctors make better-informed decisions.

There have been concerns about muscle pain, and statins can, rarely, cause severe muscle problems. However, the researchers have demonstrated that muscle pain or weakness is common in adults, regardless of whether they take a statin tablet or not. Statin treatments marginally increase the frequency of muscle-related symptoms, but they are not the cause of muscle pain in over 90% of those who experience symptoms. To put this in perspective, for every 1000 people taking a moderate intensity statin, the treatment would cause 11 (generally mild) episodes of muscle pain or weakness. 

Statin use can also cause a small increase in blood sugar levels meaning that people already at high risk of type 2 diabetes may develop it sooner. 

What do we still need to find out?

Large-scale clinical trials involving many thousands of participants and meta-analyses by Oxford Population Health scientists and others around the world have shown that statins are safe and can save lives, whether for people who have already had a heart attack or other cardiovascular problems, or those who haven’t but are thought to be at increased risk due to high cholesterol levels. However, we still need to find novel ways of identifying people who are more likely to suffer from the known side effects of statins.

For example, Oxford Population Health researchers developed a risk score to help identify patients at higher risk of muscle damage. These could be used to alert a doctor to either reduce the dose or consider alternative treatments in patients who have these risk factors.

The analysis of possible side effects listed in package leaflets showed a small increase in risk (about 0.1%) for liver blood test abnormalities. There was no increase in liver disease such as hepatitis or liver failure, indicating that the liver blood test changes do not typically lead to more serious liver problems. Future research will look at biochemical data to delve into these results in more detail.

It’s important to acknowledge that statins aren’t the single solution to heart health. Stopping smoking, eating a healthy diet, maintaining a healthy weight and staying active are all ways that people can reduce the risk of cardiovascular disease and other conditions such as diabetes or cancer. Statins are an important and proven tool on top of these interventions. 

Given how important these drugs are, it’s vital that information for the public about the risks and benefits of statins is as clear and accurate as possible, enabling people to make a properly informed decision about whether to take them. The biggest potential harm from misleading information that overstates the side effects of statins is that people who could benefit from their protective effects decide to stop taking them or not take them at all, risking the long-term debilitating effects of stroke or the devastating impact of a heart attack. Statins may not be right or necessary for everyone, but everybody is entitled to a clear, factual explanation of the scientific evidence surrounding them. 

Read information about statins from the British Heart Foundation