When is the optimal time to take caffeine?

For most people, the optimal time is 90–120 minutes after waking. This can support a steadier arc of energy and help avoid a pronounced afternoon crash. 1

• Afternoon cutoff: Avoid caffeine after 4 p.m.; even if you can fall asleep, later caffeine can disrupt sleep quality. 2
• Morning workout: If you need caffeine before intense exercise soon after waking, taking it beforehand is an option, though you may experience a stronger early-afternoon energy dip. 3
• If you can’t delay it: Have half upon waking and the other half about an hour later; this may help extend caffeine’s effects and reduce the afternoon crash. 4
• Regular caffeine users: Caffeine taken around 60–90 minutes after waking may extend the morning cortisol pulse’s downslope, which can help smooth the transition into early afternoon. 5