This subjective effect index exists to serve as a comprehensive map of all potential experiences which can occur under the influence of any class of psychoactive compound, particularly hallucinogens.

The effects identified here are accompanied by a detailed description of how it feels to experience them. These are written in an objective and consistent writing style which is based upon phenomenological observation and avoids the use of metaphor or analogy. The descriptions also strive to use language which is as simple and understandable as possible, this has been done in the hope of them eventually serving as a universal terminology set which allows people to discuss and describe that which was previously considered ineffable.

The effects are separated into over 200 distinct components which are organised into categories based on the sense they affect and their behaviour. Many of these are further broken down into leveling systems, subcomponents, and variations in style which can occur across different substances. Detailed replications are included wherever possible to supplement the text descriptions in the form of image and video examples.

Cognitive effects




psychological states

  • Catharsis
  • Delusions
  • Depersonalization
  • Depression
  • Derealization
  • Déjà vu
  • Ego replacement
  • Feelings of impending doom
  • Mania
  • Mindfulness
  • Personality regression
  • Psychosis
  • Rejuvenation
  • Suicidal ideation

Transpersonal states

  • Existential self-realization
  • Identity alteration
  • Perceived exposure to inner mechanics of consciousness
  • Perception of eternalism
  • Perception of interdependent opposites
  • Perception of predeterminism
  • Perception of self-design
  • Spirituality enhancement
  • Unity and interconnectedness

Physical effects (coming soon!)



  • Appetite suppression
  • Cough suppression
  • Decreased libido
  • Motor control loss
  • Nausea suppression
  • Orgasm suppression
  • Pain relief
  • Respiratory depression
  • Sedation
  • Seizure suppression


  • Bodily pressures
  • Bronchodilation
  • Changes in felt bodily form
  • Changes in felt gravity
  • Excessive yawning
  • Gustatory hallucinations
  • Mouth numbing
  • Muscle relaxation
  • Muscle tension
  • Muscle tremors
  • Olfactory hallucinations
  • Optical sliding
  • Perception of bodily heaviness
  • Perception of bodily lightness
  • Photophobia
  • Physical autonomy
  • Physical euphoria
  • Pupil constriction
  • Pupil dilation
  • Spontaneous physical sensations
  • Watery eyes

Uncomfortable side effects


  • Abnormal heartbeat
  • Decreased heart rate
  • Decreased blood pressure
  • Increased blood pressure
  • Increased heart rate


  • Brain zaps
  • Dizziness
  • Headaches
  • Increased bodily temperature
  • Seizure
  • Temperature regulation suppression


  • Constipation
  • Dehydration
  • Diarrhea
  • Difficulty urinating
  • Dry mouth
  • Frequent urination
  • Increased perspiration
  • Itchiness
  • Muscle contractions
  • Muscle cramps
  • Muscle spasms
  • Nausea
  • Physical fatigue
  • Restless legs
  • Runny nose
  • Salivation
  • Skin flushing
  • Stomach bloating
  • Stomach cramps
  • Teeth grinding
  • Temporary erectile dysfunction
  • Vasoconstriction
  • Vasodilation


  • Psychedelics
    • Visual effects of the psychedelic experience
    • Cognitive effects of the psychedelic experience
    • Miscellaneous effects of the psychedelic experience
  • Dissociatives
  • Deliriants