Magic mushrooms can make you tired, though the timing might surprise you. During the trip itself, psilocybin actually ramps up your body’s arousal systems, increasing heart rate, blood pressure, and stress hormones. The fatigue typically hits afterward, during the comedown and in the days that follow. In a large clinical trial published in the New England Journal of Medicine, 6% of participants who received a full dose of psilocybin reported fatigue as a side effect on the day of administration, and researchers at UC Berkeley’s Center for the Science of Psychedelics note that fatigue is one of the most commonly reported side effects in the days after psilocybin treatment.
What Happens to Your Energy During a Trip
Psilocybin’s active form, psilocin, triggers a stress response that looks a lot like your body gearing up for something intense. It activates the sympathetic nervous system, the same branch responsible for your fight-or-flight response. Your pupils dilate, your heart rate climbs, and your body releases cortisol and epinephrine. Subjectively, most people feel wired or deeply stimulated rather than sleepy while the drug is active.
That said, yawning is one of the most recognizable physical effects during a psilocybin experience. It can start within the first hour and persist throughout, which leads many people to assume they’re getting tired. But this yawning doesn’t seem to reflect genuine sleepiness. It’s more likely tied to the way psilocybin floods serotonin receptors across the brain. Serotonin plays a central role in the system that keeps you awake, and when psilocybin disrupts that system, the result is a strange mix of signals: your body may yawn repeatedly while your mind feels anything but drowsy.
Why the Comedown Feels Exhausting
The real tiredness tends to arrive once the effects wear off, typically four to six hours after ingestion. After spending hours in a state of heightened sympathetic activation, your body shifts toward recovery. Researchers describe a process called “vagal rebound,” where the parasympathetic nervous system (the branch responsible for rest and energy conservation) kicks into gear as a homeostatic response to all that earlier stress. Think of it like the crash after a prolonged adrenaline rush. Your body was running hot, and now it needs to cool down.
Reports from UC Berkeley’s psychedelics research program confirm that people commonly feel hungover, fatigued, or foggy-headed for a day or two after taking psilocybin. This isn’t unique to mushrooms; it happens with several psychedelics. But psilocybin research specifically highlights fatigue as one of the top post-treatment complaints.
The Emotional Toll Adds Up
Physical mechanisms only tell part of the story. A psilocybin experience can be profoundly emotionally demanding. People report feeling intense emotions, reliving vivid memories, and experiencing perceptual shifts like ego dissolution or a sense of timelessness. Processing that kind of psychological intensity takes energy, the same way you might feel drained after a deeply emotional conversation or a grief-heavy day, except compressed into a few hours and amplified.
This mental exhaustion often blends with the physical fatigue in ways that are hard to separate. People who have more emotionally challenging trips tend to report feeling more wiped out afterward, which makes intuitive sense. Your brain just ran a marathon of emotional processing, and it needs recovery time.
How Psilocybin Affects Sleep That Night
If you take mushrooms during the day, you might expect to crash hard that night. The reality is more nuanced. A study published in Frontiers in Pharmacology measured participants’ sleep after daytime psilocybin administration and found that total sleep time, sleep efficiency, and number of sleep cycles were essentially unchanged compared to placebo. The one notable difference: it took longer to enter REM sleep, the deep dreaming phase.
Participants also didn’t report any significant change in how well they felt they slept. The one subjective shift was that it took slightly longer to fall asleep, a finding consistent with other psychedelics like ayahuasca. So while psilocybin doesn’t appear to wreck your sleep architecture in a dramatic way, that delayed REM onset could subtly affect how rested you feel the next morning.
Animal research paints a slightly different picture. In mice, psilocin disrupted the maintenance of both REM and non-REM sleep for roughly three hours after dosing. The mice woke up more frequently, not because they were more alert, but because their ability to stay asleep was impaired. This suggests psilocybin fragments sleep rather than simply preventing it, which could contribute to next-day grogginess even if total sleep time looks normal on paper.
Microdosing and Low Energy
Fatigue isn’t limited to full psychedelic doses. The National Institutes of Health lists low energy as a reported side effect of microdosing psilocybin, alongside insomnia, poor mood, and cognitive difficulties. This is worth noting because many people microdose specifically hoping for an energy or productivity boost. For some, the opposite happens.
The mechanisms at low doses are less well studied, but the serotonin system disruption likely plays a role even at sub-perceptual levels. If psilocybin is subtly interfering with the brain’s arousal-maintaining serotonin pathways, it could leave you feeling slightly drained without the compensating stimulation that comes with a full dose.
How Long the Fatigue Lasts
For most people, the tiredness resolves within one to two days. UC Berkeley researchers describe it as feeling “hungover, fatigued, or a little foggy the day or a couple of days after.” This aligns with the drug’s pharmacology: psilocin is cleared from the body within hours, but the downstream effects on neurotransmitter balance and sleep architecture can linger briefly.
If you’re planning around a psilocybin experience, building in a recovery day is practical. The combination of disrupted sleep, emotional processing, physical stress response, and parasympathetic rebound means your body has real recovering to do, even if the experience itself felt positive. Treating the day after like you would after any physically and mentally demanding event (rest, hydration, light activity) matches what your body is actually going through.