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Substance education guide

LSD (Lysergic Acid Diethylamide)

Classical ergoline psychedelic · Partial 5-HT2A agonist

Representative photo of LSD (Lysergic Acid Diethylamide)What it looks like
Image: Drogadicta · CC BY-SA 4.0 · Wikimedia Commons. Appearance varies; illicit products may look different or be counterfeit.

01 · How it works

Classification and primary mechanism

LSD is an exceptionally potent ergoline psychedelic active at microgram levels. It acts primarily as a partial agonist at serotonin 5-HT2A receptors, with additional activity at 5-HT1A, 5-HT2C, and dopamine D1/D2 receptors. Cortical 5-HT2A activation increases glutamate release, disrupts sensory gating, and desynchronizes default-mode network activity, contributing to synesthesia and ego dissolution. A molecular binding-pocket lid helps explain its prolonged 8 to 14 hour duration.

02 · Immediate effects

Recognize the effects

Signs of Use

  • Marked pupil dilation, sweating, and goosebumps
  • Geometric visuals, tracers, and sensory blending
  • Distorted time, intense emotions, or rapidly shifting thoughts
  • Tremors, jaw tightness, elevated heart rate, or wakefulness
  • Panic, paranoia, dangerous confusion, or loss of self-boundaries

Short Term

  • Low to moderate: visual enhancement, altered time, synesthesia, and conceptual thinking
  • Moderate to high: profound perceptual distortion, emotional amplification, and ego dissolution
  • Physiologic activation: increased heart rate, blood pressure, temperature, sweating, and nausea
  • Severe psychological distress, panic, agitation, or unsafe behavior
  • Rare seizures, hyperthermia, or serotonin toxicity, especially with interactions

Long Term

  • Rapid tolerance that generally resets after several days
  • Persistent visual disturbances or hallucinogen-persisting perception disorder
  • Possible psychosis or mania precipitation in vulnerable people
  • Changes in values, worldview, or emotional processing
  • Risk from unknown adulterants and unsafe environments

03 · Long-term consequences

Adulterants and interaction risks

Pure LSD is generally odorless and tasteless, but sensory cues cannot reliably identify a substance. Lithium and some other medications can substantially increase seizure risk; combining psychedelics with stimulants, serotonergic drugs, or unknown tabs adds uncertainty. Never rely on a bitter-tab rule as proof of identity.

Medical emergency

Identifying an emergency

Call 911 for seizure, extreme hyperthermia, chest pain, collapse, severe agitation, psychosis, dangerous confusion, or behavior that cannot be kept safe. Reduce noise and stimulation, speak calmly, remove hazards, stay with the person, and do not restrain them unless needed to prevent immediate harm.

Critical interaction: Lithium combined with LSD has been associated with severe seizures
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