I have my blood samples taken about twice a year to monitor on my cholesterol levels. They are are much to high. ( My primary care physician wants to start me on statin but I won't touch that stuff because of it's reputation for causing emotional distress in users.) Since 2012, I also use three anti-seizure medications for epilepsy.

Anyway, when the nurse pushes in the needle to take my blood the little vial fills at once. She just replaces it with another vial until in just a few moments she has three or four of them, full of my fresh, liquid blood.

There's no clotting, no waiting. Certainly no request by the nurse for me to take aspirin ( a plasma thinner ) before I drop by for blood work.

After a few minutes, the puncture in my forearm clots; a bandaid isn't even needed if it drops off after an hour.