Why am I so tired after EMDR?

You feel tired after EMDR because both your brain and your nervous system have been working hard. Focusing on a memory while doing bilateral stimulation taxes your mental resources, and your body shifts from an activated state into rest afterward. Many people say this fatigue eases within a day or two, though there’s no fixed timeline for everyone.

What’s happening in your brain and body during EMDR?

EMDR looks calm from the outside: you’re sitting still, following a moving target or listening to alternating tones. Inside, it’s closer to a workout. That mismatch is exactly why the tiredness catches people off guard.

Two things are draining your tank at once: your thinking brain and your nervous system. Both are doing real work, and both need to recover afterward.

Why does sitting still leave you so drained?

Because the mental effort is real, even when the body is quiet.

Bilateral stimulation (the left-right eye movements, tones, or taps at the heart of EMDR) works partly by taxing your working memory. See our answer on whether bilateral stimulation is just relaxation with extra steps for more on that mechanism. When you hold a difficult memory in mind and track the stimulation at the same time, both compete for limited mental capacity.

A 2012 paper in the Journal of Experimental Psychopathology by van den Hout and Engelhard found that this dual-task demand on working memory is what makes the memory feel less vivid and less charged. It also means you’ve been spending real cognitive fuel.

Sustained mental effort has a measurable cost. A 2022 study in Current Biology by Wiehler and colleagues found that hours of demanding cognitive-control work led to a buildup of glutamate in the prefrontal cortex, a brain-chemistry signature of genuine mental fatigue, not just a feeling. Effortful focus tires the brain in a physical way.

Why does your nervous system crash afterward?

There’s a second layer, and it’s about arousal.

During EMDR you’re often holding something uncomfortable, so your nervous system revs up before it settles. A 2008 study in the Journal of Anxiety Disorders by Sack and colleagues measured this directly: across sessions, heart rate progressively dropped and heart-rate variability rose, showing a shift toward calmer, more parasympathetic (rest-and-digest) activity over time.

That wind-down is a good thing, but coming down off an activated state is tiring in its own right — the same heavy calm you feel after a hard cry or a tense conversation finally ending. Your body reads the all-clear and reaches for rest.

Why doesn’t the tiredness always clear by the next morning?

EMDR doesn’t fully switch off when the session does. EMDRIA, the EMDR International Association, notes that clients are briefed that some processing may continue between sessions and new material may surface. If your brain keeps quietly working in the background, it fits that many people notice tiredness lingering for a day or two rather than clearing by bedtime, though there’s no research pinning down an exact timeline.

Sleep is part of that picture. One long-standing theory, laid out in a 2002 paper in the Journal of Clinical Psychology by Robert Stickgold, proposes that EMDR engages processing similar to what happens during REM sleep, the phase when the brain integrates emotional memories. That may be part of why many people feel pulled toward deeper rest afterward. It’s a theory, not settled fact, but it fits the tiredness.

What actually helps you recover?

Treat the hours after a session as recovery time, not a window to power through your to-do list.

• Rest without guilt. Fatigue is your system asking for downtime. Let it have some.
• Hydrate and go easy. Skip stacking another demanding task right after.
• Let yourself sleep. If you feel pulled toward a nap or an early night, follow it. If rest feels hard to reach, bilateral stimulation itself can help you fall asleep.
• Ground yourself gently. Light movement, time outdoors, or a short grounding practice helps your nervous system settle. Our full after-session checklist walks through the options.
• Jot down what came up. A few notes capture insights without forcing you to keep processing.

With self-guided practice, you also control the dial. Shorter sessions and one small, everyday target (the kind of low-stakes material a wellness tool is built for) are naturally less taxing than long, high-intensity sessions. EmEase, a self-guided EMDR app, offers the guided version of this technique at app.emease.com, where you set the pace and length so recovery stays manageable.

When is tiredness a reason to slow down?

Feeling drained is usually normal. A few patterns are worth taking seriously, though, and feeling worse rather than just tired is common enough at first that it’s worth knowing where the line to concern actually sits.

If the fatigue is severe, keeps building instead of easing, or arrives alongside feeling overwhelmed, flooded, or unable to settle, that’s a signal to pause self-guided work and consider support from a trained professional. Deep or complex material isn’t a fit for going solo — our honest take on whether self-guided EMDR is safe walks through where the line sits. Self-guided EMDR is best kept to everyday stress and resilience, not heavy trauma.