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LSM-775 Facts

Psychedelic; Lysergamide; Serotonin 2A receptor agonist

Description

LSM-775 (lysergic acid morpholide) is a synthetic psychedelic of the lysergamide class. It activates serotonin receptors in two opposing ways — generating and simultaneously suppressing psychedelic signals — producing a body-heavy, muted result.[1][2]

Subjective effects include nausea, sedation, mild geometric visual patterns, mood shifts, and pervasive bodily heaviness. The experience is defined by somatic weight — a nauseogenic, heavy baseline through which faint perceptual changes emerge, less a psychedelic journey than a body burden with psychedelic undertones.[3]

LSM-775 produces no physical dependence, and no lethal dose has been established — rapid tolerance makes compulsive redosing self-limiting.[4] The dominant hazard is the pronounced body load: severe nausea, vomiting, and cardiovascular stress at effective doses, plus a theoretical risk of heart valve damage with repeated use.[1]

Dose and durationby route · individual sensitivity varies

Oral(µg)
Threshold< 250 µgLight500 – 750 µgCommon750 – 1250 µgStrong1250 – 1500 µgHeavy1500+ µg

Starts in 10 – 30 minLasts 6 – 10 hoursAfter-effects 2 – 6 hours

Body and dependence

Acute toxicity
Low
Chronic toxicity
Low
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; other lysergamides

Effectslikely at a common dose

Perception
none likely · 36 possible, including Visual haze / noise, Spatial disorientation, Vestibular distortion
Body
Pupil dilation; Body high; Body scan awareness; +33 possible, including Nausea, Muscle tension, Heart rate perception changes
Thinking
none likely · 33 possible, including Thought loops, Confusion, Cognitive impairment
Feeling
none likely · 9 possible, including Emotional lability, Anxiety, Paranoia
Self
none likely · 10 possible, including Derealization, Depersonalization
Time
Time alteration; +3 possible, including Temporal disorientation
Transpersonal
none likely · 1 possible
Awareness
none likely · 5 possible

Who shouldn't take it

Absolute
Psychotic disorders or personal history of psychosis; Concurrent MAOI use; Concurrent tramadol use
Relative
Cardiovascular disease; Concurrent lithium use; Bipolar disorder; Family history of psychotic disorders; Concurrent SSRI/SNRI use

Combinations61 recorded

Lethal (1)
MAOIs
Dangerous (17)
Dopamine agonists; Lithium; MDMA, MDA; NRIs; GHB, Baclofen; GHB, GBL; Ibogaine; Ketamine, DXM, PCP; Local anesthetics; MDMA, Amphetamines; NDRIs (Wellbutrin); Psychedelics; Salvia, Ibogaine; SNRIs; SSRIs; Stimulants; Synthetic cannabinoids
Caution (38)
See full page: psychedex.org/substances/lsm-775
Not graded (5)
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]
    ^abBrandt SD, Kavanagh PV, Twamley B, Westphal F, Elliott SP, Wallach J, Stratford A, Klein LM, McCorvy JD, Nichols DE, Halberstadt AL (2018) Return of the lysergamides. Part IV: Analytical and pharmacological characterization of lysergic acid morpholide (LSM-775) — Drug Testing and Analysis doi:10.1002/dta.2222
  2. [2]
    ^Halberstadt AL, Koedood L, Powell SB, Geyer MA (2011) Differential contributions of serotonin receptors to the behavioral effects of indoleamine hallucinogens in mice — Journal of Psychopharmacology doi:10.1177/0269881110388326
  3. [3]
    ^(2013) LSM-775 Erowid Experience Report: The Most Unique Lysergamide I've Tried Link
  4. [4]
    ^de la Fuente Revenga M, Jaster AM, McGinn J, Silva G, Saha S, Gonzalez-Maeso J (2022) Tolerance and Cross-Tolerance among Psychedelic and Nonpsychedelic 5-HT2A Receptor Agonists in Mice — ACS Chemical Neuroscience doi:10.1021/acschemneuro.2c00170
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