The Graeme Carl Scale is a five level scale for measuring the effects of a psychedelic experience.

I first came across the scale whilst doing dosing research for the New Moon psychedelic retreat project. Myself and co-founder Tuk needed a way to collect data on the strength of people’s experiences with psilocybin truffles, and we found Graeme Carl’s on Erowid.

We were aware of the Shulgin Rating Scale too, and to be honest thought that would be really cool to use, but it just wasn’t as practical and useable as this one.

We adapted a version for ourselves, making some small changes and additions, and splitting up the effects described at each level into cognitive, physical, and visual effects. It’s not a flawless categorisation of effects, but it has proven to be very useable.

Here is the adapted Graeme Carl Psychedelic Experience Scale:

Level 1

Visual

  • Brighter or clearer colours
  • Environment becomes more tangible

Cognitive

  • Some short term memory anomalies
  • Music and sounds become ‘wider’
  • Mild ‘stoning’ effect

Physical

  • No notable physical effects

Level 2

Visual

  • Things start to move and breathe
  • Some 2 dimensional patterns become apparent upon shutting eyes
  • You can control OEVs i.e. they only appear if you look carefully for them

Cognitive

  • Increase in abstract, novel, or creative thought becomes apparent
  • Confused or reminiscent thoughts
  • Continual distractive thought patterns, alternated with periods of focus

Physical

  • Body can feel heavy making standing up more difficult
  • Movement at times more difficult and balance can be off

Level 3

Visual

  • Very obvious visuals, everything looking curved and/or warped patterns and kaleidoscopes seen on walls, faces etc.
  • Some mild hallucinations such as rivers flowing in wood grained or ‘mother of pearl’ surfaces
  • Closed eye hallucinations become 3 dimensional
  • OEVs appear everywhere without any effort

Cognitive

  • Losing track of time concerning how long you have been tripping
  • Time distortions and ‘moments of eternity’

Physical

  • Movement at times becomes extremely difficult

Level 4

Visual

  • Strong hallucinations, i.e. objects morphing into other objects

Cognitive

  • Some loss of reality
  • Destruction or multiple splitting of the ego. (Things start talking to you, or you find that you are feeling contradictory things simultaneously)
  • Time becomes meaningless
  • ESP type phenomena
  • Blending of the senses: synaesthesia

Physical

  • Out of body experiences

Level 5

Visual

  • Total loss of visual connection with reality

Cognitive

  • The senses cease to function in the normal way
  • Total loss of ego
  • The actual universe within which things are normally perceived, ceases to exist

Physical

  • Merging with space, other objects or the universe
psychedelic experience five 5 level scale

The levels of the psychedelic experience scale are non-linear compared to dose, illustrated on Erowid.

Using the scale

Writing up a report after your experience can help to track your level of experience at different doses. This can give you useful data for future explorations. These reports can be kept in a journey log, AKA a drug journal.

Bear in mind that being on one level for one domain does not mean that it will be the same on another. For example, an experience could show level 2 effects on the cognitive, and level 3 on the visual. You can rate each level a different score, and then an overall, and this allows you to get a snapshot of the intensity at a glance. For example:

Cognitive: 2
Visual: 3
Physical 2
Emotional: 2

Overall: 2.3

Emotional effects aren’t included in the scale, so you can just do that one just based on your feeling. 😉

It may be that effects of more than one level can be felt. If that’s the case, score the highest domain at which effects were felt. For example, if you felt an increase in abstract thoughts (level 2) and were losing track of time (level 3), then score the cognitive level a 3.

You can read more about Graeme Carl’s Scale on Erowid here.