Ask A Scientist Chemistry Archive

Question:  Could you please tell me what is in aspirin that thins out 
the blood, especiially the blood platelets?
 tonya l tyree

Answer:
Aspirin is essentially only one thing:  acetylsalicylic acid.  How it does
some of the things it does is still a mystery.  I believe aspirin somehow
interacts with prostaglandins (short lived hormones) and makes blood cells
less sticky.  Thus aspirin also interferes with blood clotting.  I do
know that aspirin also inhibits the synthesis of prostaglandins by altering
(what else?) prostaglandin synthase (the aspirin acetylates the terminal
amino group just so you know).  And since prostaglandins enhance 
inflammation, aspirin is a good anti-inflammatory agent.
-Joe Schultz