Leesa

Aspirin is readily absorbed in the stomach and upper intestine. Within 30 to
40 minutes of ingestion, peak plasma levels are reached, but this will
depend upon which formulation is used.

Aspirin is available as solid or soluble tablets, in enteric-coated form or
in slow release form. Studies have shown that soluble tablets allow very
rapid plasma access of aspirin. Soluble aspirin formulations for instance
can enter the bloodstream within five minutes of dosing.

When aspirin is chewed, it works quickly (within 15 minutes) to prevent the
formation of blood clots.

So it depends what you are taking (formulation wise) and why you are taking
it.  Whichever way it's pretty quick.

Hope this helps

Elaine
www.pharmacy-forum.co.uk
The UK Forum for all things Pharmacy