LSD and Lithium: Why This Combination Causes Seizures
Mixing LSD and lithium can trigger seizures. Here's what the data shows, why it happens, and why this is one psychedelic interaction to take seriously.
May 31, 2026 · Jordan Mercer
Contents
If you take lithium, do not take LSD. This is one of the few psychedelic interactions with enough documented harm to treat as a hard stop rather than a caution. A 2021 analysis published in Pharmacopsychiatry found that roughly 47% of lithium-plus-psychedelic experiences involved a seizure, alongside reports of prolonged unconsciousness and hospitalization. That is not a subtle signal.
If someone is seizing right now
- Clear the area of hard or sharp objects and cushion their head.
- Do not put anything in their mouth, and do not hold them down.
- Time it. Call emergency services if the seizure lasts longer than 5 minutes, if a second one follows, or if they do not regain consciousness.
- Roll them onto their side once the convulsing stops, to protect the airway.
- Tell paramedics exactly what was taken, including the lithium. It changes how they treat it, and nobody is going to arrest you for saying it.
What the evidence shows
The strongest data is a Johns Hopkins analysis of experience reports from Erowid, Shroomery and Reddit. Researchers found 62 reports of lithium combined with a classic psychedelic. Of those, 47% described a seizure and another 18% described a bad trip or other medical emergency. For comparison, 0 of 34 reports involving lamotrigine, a different mood stabilizer, described a seizure.
This is case-report-tier evidence, which sits at the bottom of the hierarchy, and the limits are real: self-reported accounts, no toxicology, no way to verify doses or what else was in the mix. But the signal is unusually strong and consistent. When the rate in one dataset jumps from zero to nearly half depending only on which mood stabilizer someone is taking, that pattern is hard to explain away.
Two other pieces line up with it. A population-based survey of 613 lifetime psychedelic users found that among people reporting a psychedelic-related seizure, nearly half were on antidepressants, mood stabilizers or opioid replacement medication at the time, and seizures were more common in people with a personal or family history of epilepsy. And a 2024 case report described new-onset seizures in an adolescent who took LSD while on a low dose of lithium, which tells you the interaction does not need a high lithium level to hurt someone.
Why the threshold drops
A seizure is neurons firing in a synchronized, uncontrolled burst. Anything that raises excitability, or weakens the brain’s ability to damp runaway firing, lowers the threshold for that happening. LSD and lithium each push in that direction, and together they stack.
Lithium has a narrow therapeutic window and is known to be pro-convulsant at the upper end of it. It alters intracellular signaling, including the inositol and GSK-3 pathways, and increases neuronal excitability in ways that can predispose susceptible people to seizures even inside the normal dosing range.
LSD is a 5-HT2A agonist, and strong 5-HT2A activation increases cortical glutamate release and excitatory signaling across the cortex. By itself, in healthy people, LSD rarely causes seizures. Layered on lithium’s pro-convulsant baseline, that extra excitatory drive appears to be enough to tip a meaningful fraction of people into a generalized seizure. The mechanism is not fully mapped and the literature still labels the interaction provisional, but two pro-excitatory effects converging on the same circuitry is the leading explanation.
That reasoning is also why the risk is not specific to LSD. Psilocybin, mescaline and the 2C-x compounds are 5-HT2A agonists too, and the reports show seizures across that whole class on lithium. Swapping the psychedelic does not solve this.
If you take lithium and want to use psychedelics
The interaction is not dose-dependent in a way you can manage by taking less, and a seizure at a festival or in a friend’s apartment carries its own risks of injury, aspiration and status epilepticus. So the honest answer is that the psychedelic is the thing to skip, not the lithium. Three things worth knowing if you are weighing it up anyway:
- Do not stop lithium on your own to make room for a trip. Abrupt discontinuation is linked to rapid relapse and rebound mania in bipolar disorder. Any change has to be managed by a prescriber over time. This is not a do-it-yourself taper.
- Tell a clinician what you are actually considering. They cannot help you lower the risk if they are working from a version of your life that leaves this out.
- Bipolar disorder is an exclusion criterion in most psychedelic clinical trials, partly for mania risk and partly for this seizure signal. The people running trials under medical supervision, with a crash cart in the building, still decided not to take this one on.
If you use psychedelics generally, our interaction checker covers other combinations, and the LSD guide, the psilocybin guide and how to stop a bad trip cover the rest.