How long does Espresso
stay in your system?

A single espresso shot carries about 64 mg of caffeine in just one ounce. It feels stronger than drip coffee because of the concentration and speed of consumption, but a standard 8 oz mug of coffee actually delivers more total caffeine than a single shot. A double shot, around 128 mg, is where espresso overtakes a regular cup.

Starting from 64 mg, the 5-hour half-life leaves roughly 32 mg after five hours and about 16 mg after ten. A morning double shot at 128 mg behaves like two of these curves stacked, putting you near 64 mg by early afternoon.