Video: Low-dose aspirin dose depends on bodyweight

Video transcript

It’s common in Australia and in other parts of the world for people to be taking daily, low-dose aspirin - between 75 and 100 milligrams. It’s seen to prevent heart attacks or strokes, when you’ve already had a heart event. There’s also some evidence to suggest that it can help lower the risk of cancer. But is a “low dose” the same for everyone? That’s what researchers in the UK set out to determine.

This research brought together a range of different studies that had already been done on the effect of aspirin. It broke people up into groups based on their bodyweight and by their dose of aspirin - as low as 75 mg per day and, in some cases, higher than 500 mg per day. They also separated people out based on their age, sex, and whether they were already at risk of things like a heart attack or stroke.

They found that contrary to the one-size-fits-all approach to aspirin’s prescribing, the benefit people saw from taking aspirin really depended on how much they weighed. For men and women who were less than 70 kilograms, taking a daily aspirin dose of 75-100 mg was highly beneficial in terms of reducing their risk of “cardiovascular events” - again, things like heart attack and stroke. But to get a benefit if you weighed more than 70 kilograms (which many women and most men do), people had to take more than that dose. The other edge of this sword was that people who were smaller in size but who took a higher dose were at higher risk of sudden death.


If you’re currently taking aspirin for your heart, it might be wise to visit your GP and query whether the dose is right for you. The study’s authors suggest that in people who are heavier than 70 kilograms, they might like to have a lower dose of aspirin (around 100 mg) twice a day, rather than once say the authors.


Rothwell, et al. (2018). Effects of aspirin on risks of vascular events and cancer according to bodyweight and dose: analysis of individual patient data from randomised trials. The Lancet doi: 10.1016/ S0140-6736(18)31133-4.