Huberman had some solid papers. It is a real shame how far he’s gone into quack and shill nonsense
It varies a lot between people. The half-life can be anywhere from about 2 to 10 hours, and the secondary metabolites which can last longer affect people differently. When I was in my 20s I’d drink coffee all day and fall asleep with a cup in my hand at night. In my 40s, I can’t sleep 5 hours after a cup.
