Effect Categories - Physical Alterations

Physical alterations are defined as any subjective effect that changes a facet of a person's physical body in a manner which does not involve a clearly definable enhancement or suppression.

This page lists the various physical alterations that can occur under the influence of certain psychoactive compounds.


  • Body odour alteration

    Body odour alteration can be described as a distinct change in the body's natural odour that can occur in response to the ingestion of a psychoactive substance, nootropic, or medicine. It is most commonly induced under the influence of heavy dosages of stimulant compounds, such as methamphetamine and mephedrone which are often said to result in an ammonia-like odour.

  • Bronchodilation

    Bronchodilation can be described as the expansion of the bronchial air passages in the respiratory tract. A bronchodilator is a substance that dilates the bronchial tubes resulting in decreased resistance in the respiratory airway and increased airflow to the lungs.

  • Changes in felt bodily form

    Changes in felt bodily form can be described as feelings of the body shifting in its perceived physical shape, organization and form in a manner which is typically devoid of accompanying visual alterations. They are most commonly induced under the influence of heavy dosages of hallucinogenic compounds, such as psychedelics, dissociatives, and Salvinorin A.

  • Changes in felt gravity

    Changes in felt gravity can be described as feeling that the pull of gravity has shifted in its direction. For example, during this state one may feel as if they are floating forwards, backwards, upwards, downwards, or in an unspecifiable direction.

  • Excessive yawning

    Excessive yawning can be described as the experience of repeated, intensified, overly frequent, and spontaneous yawning despite a complete absence of genuine sedation or sleepiness. It is most commonly induced under the influence of moderate dosages of tryptamine psychedelic compounds, such as psilocybin, 4-AcO-DMT, 4-HO-MET, and ayahuasca.

  • Gait alteration

    Gait alteration is a change in the manner that a person walks and generally moves about throughout their environment. It is most commonly induced under the influence of moderate dosages of dissociatives such as ketamine, and especially DXM.

  • Laughter fits

    Laughter fits can be described as the experience of uncontrollable, intense, and spontaneous laughter which continue to occur despite a lack of any identifiable trigger or a feeling of humorousness. They are most commonly induced under the influence of moderate dosages of psychedelic and dissociative compounds, such as LSD, psilocybin, and nitrous oxide.

  • Mouth numbing

    Mouth numbing is a physical side effect of administering certain drugs sublingually (under the tongue) or buccally (via the cheeks and gum). The effect can be described as a distinct feeling of general numbness or tactile suppression around the tongue and mouth which can last for up to an hour after the drug has been administered.

  • Muscle relaxation

    Muscle relaxation can be described as the experience of muscles losing their rigidity or tenseness while becoming relaxed and comfortable. It is most commonly induced under the influence of moderate dosages of depressant compounds, such as various benzodiazepines, GABAergics, and opioids.

  • Perception of bodily heaviness

    Perception of bodily heaviness can be described as feeling as if one's body has significantly increased in its weight. This can result in feelings of slowness and sluggishness due to the body seeming difficult, uncomfortable, or impossible to move. It is most commonly induced under the influence of heavy dosages of depressant compounds, such as GABAergics, opioids, and antipsychotics.

  • Perception of bodily lightness

    Perception of bodily lightness can be described as feeling as if one's body has significantly decreased in its weight. This can result in feelings of increased energy and a general sense of bounciness due to the body seeming weightless and therefore effortless to move. It is most commonly induced under the influence of moderate dosages of dissociative compounds, such as ketamine, PCP, and DXM.

  • Physical autonomy

    Physical autonomy can be described as the experience of a person's own body performing simple or complex actions entirely of its own accord. It is most commonly induced under the influence of heavy dosages of dissociative compounds, such as ketamine, PCP, and DXM.

  • Physical euphoria

    Physical euphoria can be described as feelings of pleasure and comfort within and across one's body. This euphoria typically feels somewhat comparable to the endorphin rushes felt during states of excitement or love, the coziness of a comfortable bed, and the rush of an orgasm. It is most commonly induced under the influence of heavy dosages of a wide variety of compounds, such as opioids, stimulants, psychedelics, and GABAergics.

  • Pupil constriction

    Pupil constriction} (also called pinpoint pupils or miosis) can be described as the reduction of the size of a person's pupils under normal lighting conditions. It is most commonly induced under the influence of moderate dosages of opioid compounds, such as heroin, kratom, tramadol, and fentanyl.

  • Pupil dilation

    Pupil dilation can be described as the enlargement of the size of a person's pupils under normal lighting conditions. This is most commonly induced under the influence of moderate dosages of a wide variety of serotonergic compounds, such as psychedelics, dissociatives, deliriants, entactogens, various stimulants, and some antidepressants.

  • Spatial disorientation

    Spatial disorientation is the failure to perceive or perceiving incorrectly the position, motion, or altitude of oneself within the fixed coordinate system provided by the surface of the Earth and the gravitational vertical. It is most commonly induced under the influence of moderate dosages of dissociative compounds, such as diphenidine, ketamine, and DXM.