The leaflet enclosed in a sealed bottle of Norco's states that 10 grams of tylenol is the overdose mark. It all depends on yer tolerance, stomach contents and such. If yer looking for more bang for yer buck I suggest drinking a nice tall glass of tonic water which contains Quinine(if that's the correct spelling). It's basically a potentiator, and it DOES work, just dont be putting gin in there, good luck......