Amphetamine produces 66 documented subjective effects across 5 categories.
Full Amphetamine profileThe onset of oral amphetamine is gradual and businesslike. Over the course of thirty to sixty minutes, there is a steadily building sense of mental clarity and physical energy. The first noticeable change is often motivational — tasks that felt tedious or overwhelming suddenly seem approachable, even interesting. Attention narrows and sharpens; the mind locks onto whatever it is directed toward with an unusual tenacity. There is a mild euphoria, though it is less dramatic than that of cocaine — more of a clean, confident optimism than an ecstatic rush.
As the drug reaches full effect, the experience is dominated by a sense of focused productivity. Thoughts come quickly and in orderly sequence. Conversation becomes more fluid and purposeful. Physical energy is elevated but controlled — there is endurance and wakefulness without the jittery restlessness that characterizes higher doses. Appetite vanishes almost completely, and the user may go hours without eating or feeling hungry. There is a mild but persistent elevation of mood that makes social interaction more enjoyable and physical tasks less burdensome. The body feels light and capable.
The physical side effects build alongside the cognitive effects. Heart rate increases moderately. Mouth becomes dry and stays dry despite drinking water. There may be a slight tremor in the hands, and the jaw tends to clench. Peripheral vasoconstriction can make the hands and feet feel cold. At therapeutic doses, these effects are generally tolerable and fade into the background of awareness. At higher recreational doses, the stimulation becomes more pronounced — the heartbeat becomes uncomfortably noticeable, the jaw clenching intensifies, and the focused clarity can narrow into an obsessive fixation on a single task or line of thought that may not actually be productive.
The duration of oral amphetamine is considerably longer than cocaine — typically six to ten hours of noticeable effect, with the peak occurring around two to four hours in. The descent from the peak is gradual rather than abrupt, which reduces the compulsive redosing pattern seen with shorter-acting stimulants. However, as the drug wears off, there is a characteristic rebound: energy drains away, motivation plummets, and a heavy, irritable fatigue sets in. The appetite that was absent for hours suddenly returns with force.
The crash following amphetamine use can last twelve to twenty-four hours and is marked by exhaustion, increased sleep need, low mood, and difficulty concentrating. Heavy or prolonged use intensifies this rebound considerably and can produce a depressive state that takes several days to fully resolve. Many users also report a period of emotional blunting during the active phase — the drug provides energy and focus but can flatten the emotional range, making the user efficient but somewhat robotic.
Abnormal heartbeat (arrhythmia) is any deviation from the heart's normal rhythm — including beats that are too fast (tachycardia), too slow (bradycardia), or irregularly spaced — and represents one of the more medically significant cardiovascular effects of psychoactive substances.
Appetite changesComplex alterations in hunger, food preferences, and eating patterns that go beyond simple suppression or enhancement of appetite.
Appetite suppressionA distinct decrease in hunger and desire to eat, ranging from reduced interest in food to complete disinterest or even physical revulsion at the thought of eating. This effect can persist for many hours beyond the primary experience.
BronchodilationBronchodilation is the widening of the bronchial airways in the lungs, reducing resistance to airflow and producing a subjective sensation of easier, deeper, and more comfortable breathing.
DehydrationA state of insufficient bodily hydration manifesting as persistent thirst, dry mouth, and physical discomfort, often caused by increased sweating, urination, or simply forgetting to drink water during substance use.
Difficulty urinatingDifficulty urinating, also known as urinary retention, is the experience of being unable to easily pass urine despite a full bladder, commonly caused by stimulant, opioid, and anticholinergic substances that affect bladder muscle control.
Dry mouthA persistent, uncomfortable reduction in saliva production causing the mouth and throat to feel parched, sticky, and difficult to swallow through, commonly known as cottonmouth.
Frequent urinationIncreased urinary frequency beyond normal patterns, caused by diuretic effects or bladder irritation from substances like alcohol, caffeine, and ketamine.
Increased blood pressureIncreased blood pressure (hypertension) is an elevation of arterial pressure above the normal 120/80 mmHg baseline, commonly caused by stimulants, vasoconstrictors, and substances that activate the sympathetic nervous system, posing cardiovascular risks that increase with dose and pre-existing conditions.
Increased bodily temperatureIncreased bodily temperature (hyperthermia) is an elevation of core body temperature above the normal 37C (98.6F) baseline, caused by substances that increase metabolic rate, impair thermoregulation, or promote sustained physical activity, and representing one of the most dangerous physical effects when severe.
Increased heart rateA noticeable acceleration of heartbeat that can range from a subtle awareness of one's pulse to a forceful, rapid pounding felt throughout the chest, neck, and temples. This effect is among the most commonly reported physiological responses to psychoactive substances and often accompanies stimulation, anxiety, or physical exertion during intoxication.
Increased libidoA marked enhancement of sexual desire, arousal, and sensitivity to erotic stimuli that can range from a gentle heightening of romantic interest to an overwhelming, all-consuming preoccupation with sexual thoughts and physical intimacy. This effect often co-occurs with tactile enhancement and empathy, creating a distinctly sensual state of consciousness.
InsomniaA persistent inability to fall asleep or maintain sleep despite physical tiredness, often characterized by a racing mind, heightened alertness, and a frustrating disconnect between bodily fatigue and mental wakefulness. This effect can persist for hours beyond the primary duration of a substance, significantly extending the total experience timeline.
Muscle tensionPersistent partial contractions or tightening of muscles that produces uncomfortable stiffness, cramping, and low-level aches throughout the body.
NauseaAn uncomfortable sensation of queasiness and stomach discomfort that may or may not lead to vomiting, often occurring during the onset phase of many substances.
PhotophobiaAn abnormal physical intolerance and sensitivity to light that causes discomfort, squinting, or pain in the eyes, typically linked to substance-induced pupil dilation.
Physical euphoriaAn intensely pleasurable bodily sensation that can manifest as waves of warmth, tingling electricity, or a full-body orgasmic glow radiating outward from the core. This effect is often described as one of the most rewarding physical sensations available through psychoactive substances and is a primary driver of the recreational appeal of many substance classes.
Pupil dilationA visible enlargement of the pupil diameter (mydriasis) that can range from subtle widening to dramatic saucer-like expansion where the dark pupil dominates the iris. This effect is one of the most recognizable signs of psychedelic and stimulant intoxication and directly contributes to light sensitivity, enhanced color perception, and the characteristic "wide-eyed" appearance.
Restless legsRestless legs is an uncomfortable neurological effect characterized by an irresistible compulsion to move the legs (and sometimes other limbs) to relieve unpleasant crawling, aching, or tingling sensations, particularly during periods of rest or inactivity.
SeizureUncontrolled brain electrical activity causing convulsions and loss of consciousness -- a life-threatening medical emergency requiring immediate help.
Serotonin syndromeSerotonin syndrome is a potentially fatal medical emergency caused by excessive serotonergic activity in the central and peripheral nervous systems, typically resulting from combining multiple serotonin-elevating substances, and manifesting as a dangerous triad of neuromuscular hyperactivity, autonomic dysfunction, and altered mental status.
Stamina enhancementStamina enhancement is an increase in one's ability to sustain physical and mental exertion over extended periods without succumbing to fatigue, achieved through substances that modulate energy metabolism, pain perception, or central fatigue signaling.
StimulationA state of heightened physical and mental energy characterized by increased wakefulness, elevated motivation, and a subjective sense of vigor that pervades both body and mind. Users often report feeling electrically alive, with a buzzing readiness to move, talk, and engage that can range from a pleasant caffeine-like lift to an overwhelming, jittery compulsion to act.
Teeth chatteringTeeth chattering is an involuntary, rhythmic movement of the jaw that produces rapid clicking or chattering of the teeth, occurring independently of cold or fear and typically associated with serotonergic stimulation.
Teeth grindingAn involuntary clenching and rhythmic grinding of the jaw muscles, known clinically as bruxism, that produces a compulsive need to clench, chew, or gnash the teeth together. This effect can range from a subtle tightness in the jaw to forceful, repetitive grinding that can cause significant dental damage and jaw pain during and after the experience.
Temporary erectile dysfunctionTemporary erectile dysfunction is the substance-induced inability to achieve or sustain a penile erection sufficient for sexual activity, caused by vasoconstriction, sympathetic nervous system overactivation, or altered neurotransmitter signaling, and resolving once the drug's effects wear off.
VasoconstrictionA narrowing of blood vessels throughout the body that produces sensations of cold extremities, tingling in the fingers and toes, and a general feeling of circulatory restriction. Users may notice their hands and feet becoming pale, numb, or uncomfortably cold, sometimes accompanied by a sense of tightness in the chest or head.
Perceived increase or decrease in environmental brightness beyond actual illumination levels, common with stimulants and psychedelics (brightening) or sedatives (darkening).
DriftingThe visual experience of perceiving stationary objects, textures, and surfaces as appearing to flow, breathe, melt, or shift in position. Drifting is one of the most fundamental and commonly reported visual distortions under the influence of psychedelic substances, serving as the perceptual foundation upon which many other visual effects are built. It manifests as a fluid, organic sense of motion embedded in otherwise static visual fields.
GeometryThe experience of perceiving complex, ever-shifting geometric patterns superimposed over the visual field or visible behind closed eyelids. Geometry is widely considered the hallmark visual effect of psychedelic substances, ranging from simple lattice patterns and honeycombs at low doses to infinitely complex, self-transforming fractal structures at high doses that can feel profoundly meaningful and awe-inspiring.
TracersMoving objects leave visible trails of varying length and opacity behind them, similar to long-exposure photography. Trails may match the object color or appear in other hues.
TransformationsObjects and scenery undergo perceived visual metamorphosis, smoothly shapeshifting into other recognizable forms over seconds. Patterns morph into faces, animals, and imagery.
Visual processing accelerationA visual effect in which the brain appears to process visual information at an accelerated rate, causing fast-moving objects and rapidly unfolding events to appear as though they are occurring in slow motion.
A perceived improvement in one's ability to logically deconstruct concepts, recognize patterns, and reach novel conclusions, often accompanied by deep states of contemplation and an abundance of insightful ideas.
AnxietyIntense feelings of apprehension, worry, and dread that can range from a subtle background unease to overwhelming panic attacks with a sense of impending doom, often amplified by the substance's intensification of one's existing mental state.
Cognitive dysphoriaA cognitive and emotional state of intense dissatisfaction, discomfort, and malaise encompassing feelings of depression, irritability, existential unease, and a pervasive sense that something is fundamentally wrong. This is the mental counterpart to physical dysphoria.
Cognitive euphoriaA cognitive and emotional state of intense well-being, elation, happiness, and joy that manifests as a profound mental contentment and positive outlook. This ranges from gentle feelings of optimism and warmth to overwhelming bliss that pervades all thoughts and perceptions.
Cognitive fatigueMental exhaustion and difficulty sustaining thought after intense cognitive experiences, common during substance comedowns.
Compulsive redosingAn overwhelming, difficult-to-resist urge to continuously take more of a substance in order to maintain or intensify its effects, often overriding rational judgment and self-control.
ConfusionAn impairment of abstract thinking marked by a persistent inability to grasp or comprehend concepts and situations that would normally be perfectly understandable during sobriety.
DelusionA delusion is a fixed, false belief that is held with unshakeable certainty and is impervious to contradicting evidence or rational argument — often involving grandiose, persecutory, or bizarre themes that are clearly at odds with observable reality.
DepressionA persistent state of low mood, emotional numbness, hopelessness, and diminished interest or pleasure in activities, often occurring during comedowns, withdrawal, or as a prolonged after-effect of substance use.
Dream potentiationEnhanced dream vividness, complexity, and recall, often occurring as REM rebound after discontinuing REM-suppressing substances.
Dream suppressionDream suppression is a decrease in the intensity, frequency, and recollection of dreams — ranging from dreams becoming vaguer and less vivid to the complete cessation of any remembered dream activity — most commonly produced by substances that alter REM sleep architecture.
Ego inflationGrandiose overconfidence and inflated self-importance, opposite of ego death, commonly produced by stimulants and associated with reckless behavior.
Emotion suppressionA blunting or flattening of emotional experience in which feelings become muted, distant, or seemingly absent. The individual may recognize intellectually that they should be feeling something in response to a situation — joy at good news, sadness at a loss, anxiety about a threat — yet the emotional charge simply is not there, as though an invisible pane of glass separates them from their own feelings.
Emotional bluntingReduced capacity to experience the full range of emotions, resulting in flattened affect, commonly associated with chronic SSRI and benzodiazepine use.
Focus enhancementAn enhanced ability to direct and sustain attention on a single task or stimulus with unusual clarity and persistence, often accompanied by reduced distractibility and a heightened sense of mental sharpness and productivity.
IrritabilityIrritability is a sustained state of emotional reactivity in which the threshold for annoyance, frustration, and anger is significantly lowered — causing minor inconveniences, social interactions, or environmental stimuli that would normally be tolerated without difficulty to provoke disproportionate agitation or hostility.
ManiaAbnormally elevated mood, energy, and activity with impulsive behavior and grandiosity, associated with stimulant use and certain drug interactions.
Memory enhancementMemory enhancement is a state of improved mnemonic function in which past memories become unusually accessible, vivid, and detailed — sometimes surfacing long-forgotten experiences with the clarity and emotional intensity of reliving them firsthand.
Mixed emotionsMixed emotions is a state in which several conflicting emotional states are experienced simultaneously rather than sequentially, producing a complex and often bewildering inner landscape where happiness coexists with grief, love with fear, or contentment with unease — all at once.
Motivation enhancementA heightened sense of drive, ambition, and willingness to accomplish tasks, making productive effort feel rewarding and almost effortless.
Motivation suppressionMotivation suppression is a state of diminished drive and willingness to engage in goal-directed behavior — from everyday tasks like cleaning and working to activities that would normally be experienced as rewarding or enjoyable — sometimes described as a profound and enveloping 'why bother?' feeling.
Panic attackA panic attack is a discrete episode of acute, overwhelming fear or terror that arises suddenly and peaks within minutes, accompanied by distressing physical symptoms including rapid heartbeat, shortness of breath, chest tightness, trembling, dizziness, and a profound sense that one is dying, going insane, or losing control.
ParanoiaIrrational suspicion and belief that others are watching, plotting against, or intending harm toward oneself, ranging from mild unease to overwhelming terror.
PsychosisPsychosis is a serious psychiatric state involving a fundamental break from consensus reality — characterized by firmly held false beliefs (delusions), perception of things that are not there (hallucinations), disorganized thought and speech, and a loss of the ability to distinguish internal mental events from external reality.
Suggestibility suppressionSuggestibility suppression is a state of heightened skepticism and resistance to external influence in which a person becomes markedly less willing to accept ideas, suggestions, or directives from others at face value. It often manifests as a stubborn insistence on independent verification before agreeing with or acting upon anything said by another person.
Thought accelerationThe experience of thoughts occurring at a dramatically increased rate, as if the mind has been shifted into a higher gear. Ideas, associations, and internal dialogue cascade rapidly, often outpacing the ability to articulate or fully process each one, producing a subjective sense of heightened mental velocity.
Thought decelerationThe experience of thoughts occurring at a markedly reduced pace, as if the mind has been placed into slow motion. Internal dialogue becomes sparse and sluggish, with each idea taking longer to form and process, producing a sense of mental heaviness or cognitive inertia.
Thought loopsBecoming trapped in a repeating cycle of thoughts, actions, and emotions that loops every few seconds to minutes. Short-term memory lapses cause the sequence to restart.
Thought organizationEnhanced ability to structure, categorize, and systematize thoughts and ideas, common with low-dose stimulants and some nootropics.
Time distortionSubjective perception of time becomes dramatically altered — minutes may feel like hours, or hours pass in moments. Can manifest as either dilation or compression.
WakefulnessAn increased ability to stay awake and alert without the desire to sleep. Distinct from stimulation in that it does not elevate energy above a naturally rested baseline.
Amphetamine can produce 27 physical effects including stimulation, increased libido, appetite suppression, physical euphoria, and 23 more.
Yes. Amphetamine can produce 6 visual effects including transformations, drifting, geometry, tracers, and 2 more.
Amphetamine produces 31 cognitive effects including analysis enhancement, focus enhancement, motivation enhancement, thought acceleration, and 27 more.