Caffeine and Modafinil: Interaction Overview
Modafinil promotes wakefulness primarily via orexin/hypocretin pathway activation and partial dopamine reuptake inhibition.
Mechanism of Interaction
Modafinil promotes wakefulness primarily via orexin/hypocretin pathway activation and partial dopamine reuptake inhibition. Caffeine works via adenosine receptor antagonism. While their primary mechanisms differ, both increase sympathetic nervous system activity, raise heart rate, and decrease sleep pressure. Combined, the risk of palpitations, elevated blood pressure, anxiety, and insomnia increases substantially — particularly at higher modafinil doses (200mg+).
Recommendation
If combining, use minimal caffeine (50–100mg max) and only early in the day. Avoid combining on modafinil days if you're caffeine-sensitive. Monitor heart rate. Many experienced modafinil users drop caffeine entirely on modafinil days.
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