Physical alterations

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. Depending on the biochemical makeup of the substance the alterations in body odour can vary significantly.^{[citation needed]}

Body odour alteration is often accompanied by other coinciding effects such as increased perspiration and temperature regulation suppression. 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 odor.

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. From a subjective standpoint, this effect makes it feel as if has become significantly easier and more comfortable to breathe.

Bronchodilation is often accompanied by other coinciding effects such as stimulation. It is most commonly induced under the influence of moderate dosages of stimulant compounds, such as amphetamine,^[1] methamphetamine, and cocaine,^[2]. These compounds were historically used often for treating asthma but are now rarely, if ever, used medically for their bronchodilation effect.

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. For example, feelings of the body folding into itself many times over, stretching, splitting into separate parts, expanding, or condensing into, over, and across itself in extremely complex forms are all entirely possible. It is worth noting that although this effect is usually perfectly comfortable to undergo, it can sometimes be somewhat uncomfortable under certain circumstances.

Changes in felt bodily form are often accompanied by other coinciding effects such as perspective hallucinations, perspective distortions, and changes in felt gravity. 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 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.

Changes in felt gravity are often accompanied by other coinciding effects such as geometry, internal hallucinations, and holes, spaces and voids. They are most commonly induced under the influence of heavy dosages of hallucinogenic compounds, such as psychedelics, dissociatives, cannabinoids, and salvinorin A.

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.

Excessive yawning is often accompanied by other coinciding effects such as increased salivation and a runny nose. 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.

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.

The NBOMe series (25C-NBOMe, 25B-NBOMe, and 25I-NBOMe) cause this effect consistently and it is accompanied by a strong, unpleasant, metallic chemical taste immediately after sublingual absorption.

The stimulant known as cocaine also causes numbing of the tongue, gums, and mouth when administered sublingually. Many people test the purity of their cocaine by rubbing it in their mouth. This, however, is not a guarantee of the drug's quality as it is common for cocaine to be cut with various other numbing agents and local anesthetics, such as novocaine, lidocaine, or benzocaine, which mimic or add to cocaine's numbing effect.

Muscle relaxation can be described as the experience of muscles losing their rigidity or tenseness while becoming relaxed and comfortable. This effect is particularly useful for those who are currently suffering from muscle spasms, pain, and hyperreflexia.

Muscle relaxation is often accompanied by other coinciding effects such as sedation and anxiety suppression. It is most commonly induced under the influence of moderate dosages of depressant compounds, such as various benzodiazepines, GABAergics, and opioids. However, it can also occur to a lesser extent under the influence of cannabinoids.

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.

Perception of bodily heaviness is often accompanied by other coinciding effects such as sedation and muscle relaxation. It is most commonly induced under the influence of heavy dosages of depressant compounds, such as GABAergics, opioids, and antipsychotics. However, it can also occur under the influence of certain sedating psychedelics such as certain LSA, psilocybin, and 2C-C.

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.

Perception of bodily lightness is often accompanied by other coinciding effects such as stimulation and physical disconnection. It is most commonly induced under the influence of moderate dosages of dissociative compounds, such as ketamine, PCP, and DXM. However, it can also occur under the influence of certain stimulating psychedelics such as certain LSD, 4-HO-MET, and 2C-B.

Physical autonomy can be described as the experience of a person's own body performing simple or complex actions entirely of its own accord. Depending on the intensity, this results in the carrying out of a given task becoming partially to completely automatic in nature without the requirement of decision-making skills or attentive conscious input.

At lower levels, the effect is partially controllable by commanding the body with simple thoughts. For example, thoughts such as "go to the toilet" or "go drink a glass of water" can result in the body performing these actions autonomously. This can often help the person perform necessary physical actions such as tending to bodily functions or avoiding danger when they would otherwise be too incapable, unconscious, or distractible to perform them manually in their current state.

At higher levels, this effect no longer requires verbal commands and becomes entirely automatic. It's worth noting that although this technically results in a loss of cognitive control, the body only performs actions which the owner would have decided to perform were they capable of it themselves.

Physical autonomy is often accompanied by other coinciding effects such as physical disconnection and cognitive disconnection. It is most commonly induced under the influence of heavy dosages of dissociative compounds, such as ketamine, PCP, and DXM. However, it can also occur to a lesser extent under the influence of heavy dosages of psychedelics such as LSD, psilocybin, and mescaline, as well as cannabinoids such as cannabis.

Physical euphoria can be described as feelings of pleasure and comfort within and across the body. This euphoria typically feels somewhat comparable to the endorphine rushes felt during states of excitement or love, the coziness of a comfortable bed, and the rush of an orgasm. The forcefulness of this effect can range from subtle in its strength to overwhelmingly pleasurable beyond even the most intense full body orgasm possible.

Physical euphoria is often accompanied by other coinciding effects such as cognitive euphoria and muscle relaxation. It is most commonly induced under the influence of heavy dosages of a wide variety of compounds, such as opioids, stimulants, and GABAergics. However, it can also occur in a more powerful although less consistent form under the influence of psychedelics and dissociatives.

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. This typically decreases a person's ability to see in low light conditions.

Pupil constriction is most commonly induced under the influence of moderate dosages of opioid compounds, such as heroin, kratom, tramadol, and fentanyl.

Pupil dilation (also called mydriasis) can be described as the enlargement of the size of a person's pupils under normal lighting conditions. Normally, the pupil size increases in the dark and shrinks in the light, however, a dilated pupil will remain excessively large even in a bright environment.

Pupil dilation 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^[3] and some antidepressants.

• Subjective effect index
• Uncomfortable physical effects
• Physical effects