A review of existing evidence on the cholesterol-lowering drugs statins has concluded they are safe to take, and that their benefits have been underestimated while their side-effects have been exaggerated.
What are statins?
Statins are drugs that help to lower harmful cholesterol levels in the body by slowing down the production of cholesterol in the liver.
Around 6 million people take the drugs in the UK. They are given to people who have already had a cardiovascular event, such as a heart attack or stroke, and to people who are at risk because of their age, high blood pressure or other factors.
What does the review say?
Published in the Lancet, it is an examination of studies into statins since they were first introduced in the 1980s.
There has been controversy over how widely they should be used, and especially if they should be given to otherwise well people who are at risk of cardiovascular disease.
There have also been concerns about potential side-effects, particularly muscle pain.
However, the Lancet says the best-designed studies into statins over the years show they have significant benefits in reducing the number of people who become ill or even die from heart attack and stroke.
The authors say there have been "misleading claims" about side-effects which have meant people who could benefit from statins have stopped taking them.
The review is backed by major health organisations, including the Royal College of GPs and the British Heart Foundation.
What are the arguments against statins?
Some doctors are concerned about the drug being over-prescribed - especially for people who haven't had any cardiovascular symptoms.
It is possible to make lifestyle changes to lower cholesterol, such as a healthier diet, with less saturated fat and more fruit, vegetables and fibre, and being more active.
How many will experience side-effects?
This is a question to which the Lancet review sought to give a definitive answer.
All drugs have side-effects, and doctors will discuss these with a patient when they are considering taking them.
The Lancet says that in 10,000 people, on an average dose, there would be between 50 and 100 cases - so up to 1% - of side-effects such as muscle pain, which could be addressed by lowering the dose of statins or even stopping taking the drug.
An article in another journal, the British Medical Journal, published in 2013, suggested up to 20% of people would have side-effects - but these figures were later withdrawn and the BMJ said the data they was based on was incorrect.
Editor Fiona Godlee said it was: "So that patients who could benefit from statins are not wrongly deterred from starting or continuing treatment because of exaggerated concerns over side-effects."
What if I already take statins?
The experts who put together the review did so with the aim of reassuring patients who are already taking statins, or who may do so in the future.
However, anyone with any concerns should discuss them with their doctor.