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1P-LSD Facts

Psychedelic; Lysergamide; Serotonin 2A receptor agonist

Description

1P-LSD (1-propionyl-lysergic acid diethylamide) is a synthetic psychedelic of the lysergamide class. Once converted, it activates serotonin receptors in the brain, producing the visual and cognitive shifts characteristic of classical psychedelics.[1]

Subjective effects include geometric visual patterns, vivid color enhancement, time alteration, thought acceleration, emotional intensification, and ego dissolution.[2] The experience is slow-building and panoramic — lasting many hours, with a stimulant-edged quality that distinguishes it from shorter psychedelics like psilocybin.[3]

1P-LSD does not produce physical dependence, and no death from its direct pharmacological action has been documented.[1] The real risks are psychological — acute panic and potential psychosis in vulnerable individuals — and intensify sharply when combined with serotonin-raising drugs, which can trigger a life-threatening overheating crisis.[4]

Dose and durationby route · individual sensitivity varies

Oral(µg)
Threshold< 15 µgLight25 – 75 µgCommon75 – 150 µgStrong150 – 300 µgHeavy300+ µg

Starts in 20 – 60 minLasts 8 – 12 hoursAfter-effects 6 – 24 hours

Body and dependence

Acute toxicity
Negligible
Chronic toxicity
Negligible
Physical dependence
None
Psychological dependence
Negligible
Withdrawal
None recorded
Compulsive redosing
Negligible

Tolerance

Builds
Rapid
Fully resets after
14 days
Carries over to
LSD; psilocybin; mescaline; DMT; DOI; 2C-B

Effectslikely at a common dose

Perception
Color enhancement; Visual drifting; Color alteration; Music enhancement; Geometry; Visual breathing; +28 possible, including Spatial disorientation, Vestibular distortion, Visual haze / noise
Body
Stimulation; Pupil dilation; Wakefulness; Body scan awareness; +23 possible, including Insomnia, Vasoconstriction, Muscle tension
Thinking
none likely · 33 possible, including Suggestibility enhancement, Cognitive impairment, Confusion
Feeling
Emotional enhancement; +8 possible, including Emotional lability, Anxiety, Paranoia
Self
none likely · 9 possible, including Derealization, Depersonalization
Time
Time alteration; +3 possible, including Temporal disorientation
Transpersonal
none likely · 1 possible
Awareness
none likely · 4 possible

Who shouldn't take it

Absolute
Psychotic disorders; Bipolar disorder; Pregnancy; Concurrent MAOI use; Concurrent tramadol use
Relative
Uncontrolled hypertension; Epilepsy; Hepatic impairment; Concurrent lithium use

Combinations60 recorded

Lethal (1)
MAOIs
Dangerous (19)
MDMA, MDA; Buspirone; DXM; GHB, Baclofen; GHB, GBL; Ibogaine; Ketamine, DXM, PCP; Lithium; Local anesthetics; MDMA, Amphetamines; NDRIs (Wellbutrin); NRIs; NSAIDs; Psychedelics; Salvia, Ibogaine; SNRIs; SSRIs; Stimulants; Synthetic cannabinoids
Caution (36)
See full page: psychedex.org/substances/1p-lsd
Not graded (4)
Not listed never means safe.

Seek help immediately if

Most difficulty is psychological (intense fear, panic, confusion) and passes with calm support — the signs below mean seek emergency help:

  • Very high body temperature; hot, dry skin
  • Seizures
  • Chest pain; fast or irregular heartbeat
  • Severe muscle rigidity, tremor, or twitching (possible serotonin syndrome)
  • Cold, pale, or blue fingers/toes — severe vasoconstriction (notably NBOMe / DOx)
  • Persistent vomiting; unconsciousness; uncontrollable agitation or risk of self-harm

What to do

  1. Stay calm and reassure — remind them they took a drug and the effect will pass
  2. Move to a calm, quiet, safe space with low light; reduce noise and sensory input
  3. Keep them from harm — they may act on fear or confusion; stay with them, don't leave them alone
  4. Talk them down gently; don't grab or restrain unless they're in danger
  5. For the medical signs above (overheating, seizure, chest pain, vasoconstriction, unresponsive) call emergency services
  6. If overheating, cool the body; be ready to give rescue breaths / CPR

The experience is time-limited and usually resolves with calm reassurance in a safe setting — psychological first aid, not medication. Serious physical harm is uncommon for classic psychedelics (LSD, psilocybin) but real for some potent phenethylamines (NBOMe, DOx), where hyperthermia, seizures, and vasoconstriction warrant emergency care.

988 Suicide & Crisis LifelineFireside Project: 62-FIRESIDE

Version r1 · Not medical advice

References

  1. [1]
    ^abNichols DE (2016) Psychedelics — Pharmacological Reviews doi:10.1124/pr.115.011478
  2. [2]
    ^Holze F, Ley L, Müller F, Becker AM, Straumann I, Vizeli P, Kuehne SS, Roder MA, Duthaler U, Kolaczynska KE, Varghese N, Eckert A, Liechti ME (2022) Direct comparison of the acute effects of lysergic acid diethylamide and psilocybin in a double-blind placebo-controlled study in healthy subjects — Neuropsychopharmacology doi:10.1038/s41386-022-01297-2
  3. [3]
    ^Vizeli P, Studerus E, Holze F, Schmid Y, Dolder PC, Ley L, Straumann I, Becker AM, Müller F, Arikci D, Liechti ME (2024) Pharmacological and non-pharmacological predictors of the LSD experience in healthy participants — Translational Psychiatry doi:10.1038/s41398-024-03074-9
  4. [4]
    ^Malcolm B, Thomas K (2022) Serotonin toxicity of serotonergic psychedelics — Psychopharmacology doi:10.1007/s00213-021-05876-x
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