Low-dose aspirin of little benefit to most

Lancet study warns against the one-size fits all approach

Low-dose aspirin is ineffective for most people taking it to help prevent vascular events, a Lancet analysis of 120,000 people reveals.

For those weighing more than 70kg (which is 80% of men and nearly 50% of women), low-dose (75-100mg) aspirin is unlikely to do much good.

Instead, these patients require higher doses (300-325mg or 500mg), the researchers found, especially those who smoke or take enteric-coated aspirin.

Conversely, lighter people can expect to still benefit from low-doses of aspirin, the researchers say. 

The findings were consistent for daily and alternate-day dosing.

A one-dose-fits-all approach to aspirin is not recommended, they say.

“Loss of efficacy can occur if the aspirin dose is too low or too high for body size, and other harms appear to result from excess dosing,” writes the University of Oxford’s Professor Peter Rothwell and colleagues