Come down

"Come down" is the post-peak descending phase of cannabis intoxication during which plasma THC and subjective drug effect decline from maximum. As plasma THC falls due to redistribution into tissues (primarily fat) and hepatic metabolism, CNS effects wane, but brain concentrations lag plasma — so subjective effects decay more slowly than plasma in the first hours. Users frequently describe fatigue, mild sedation, dysphoria, brain fog, headache, or appetite/mood shifts in the hours after peak, particularly after edibles where the protracted 11-OH-THC phase contributes to "hangover-like" symptoms (MacCallum & Russo 2018). This is distinct from withdrawal (Part 9), which arises only after repeated sustained use on discontinuation. Impairment on driving-relevant tasks resolves within ~5–7 hours after 20 mg inhaled THC, though oral effects persist longer (Spindle 2018; McCartney 2021). "Come down" lacks a formal pharmacologic definition but operationally spans Tmax (or subjective peak) to baseline return. Citations: Grotenhermen F. Clin Pharmacokinet. 2003;42:327-360; MacCallum CA, Russo EB. Eur J Intern Med. 2018;49:12-19; Spindle TR et al. JAMA Netw Open. 2018;1(7):e184841.