Evidence was largely collected from published meta-analyses and systematic reviews that focused on randomised, controlled, double-blind clinical trials, in which aspirin was compared to placebo and, in some cases also, to active comparators such as OTC doses of paracetamol or ibuprofen.
Across a large number of comparisons, aspirin was superior to placebo in treating pain, cold or fever. Efficacy was essentially similar to that of comparators used in equivalent doses. There was no serious GI adverse event attributed to ASA in any study, but mild-to-moderate dyspepsia in small percentages of cases was commonly reported.
OTC aspirin is safe and effective. Safety concerns should not limit brief use to relieve acute pain, cold or fever.