Amphetamine
(±)-1-phenylpropan-2-amine
Overview
Amphetamine belongs to Stimulants.
Effects
Subjective effects vary. What a substance feels like depends on dose, individual physiology,
mindset, and setting. The points below describe commonly reported effects, not guaranteed, uniform, or
desirable outcomes.
- Increased energy, wakefulness, alertness and concentration, with reduced appetite and fatigue.
- Euphoria, confidence, sociability and talkativeness, more pronounced at higher or recreational doses.
- Sympathomimetic effects: raised heart rate and blood pressure, dilated pupils, dry mouth and jaw clenching.
- At high doses, on binges or with chronic use: anxiety, irritability, insomnia, paranoia and stimulant psychosis, followed by a fatigued, low-mood 'comedown'.
Dosing & duration
Harm-reduction note: These are commonly cited reference ranges, not a recommendation or a
“safe” dose. Potency, purity, body chemistry, tolerance, and drug combinations vary widely. Start
low, go slow, wait for full effects before redosing, and never assume an unknown product matches these
figures. Missing data is not evidence of safety.
Oral, Insufflated. The therapeutic figures are for a prescription medicine and are individualised and titrated by a clinician, not recreational guidance. Recreational use and insufflation carry higher cardiovascular, dependence and psychosis risk. Never combine amphetamine with MAOIs (hypertensive crisis) or with other stimulants. Illicit 'speed' is of variable, usually low purity and often adulterated, so the actual dose is unpredictable.
Dose ranges
ADHD (therapeutic)
≈5–40 mg/day, divided (individualised)
Narcolepsy (therapeutic)
up to ~60 mg/day
Recreational (not advised)
commonly ~10–30 mg oral
Duration
onset
≈30–60 min (oral)
peak
≈2–3 h
total
≈4–6 h (immediate-release), half-life 9–14 h
Chemical & Physical Properties
| Formula | C9H13N |
| Molar mass | 135.21 g/mol |
| State | Liquid |
| Melting point | Not reported |
| Boiling point | 200–203 °C |
| Density | 0.93 g/cm³ |
| Vapor pressure | 2.9–3.5 hPa at 20 °C |
| pKa | 10.13 |
| LogP | 1.8 (predicted, XLogP3) |
| Solubility | slightly soluble in water, soluble in ethanol and diethyl ether |
| Refractive index | 1.518 at 26 °C |
Identifiers & Synonyms
| CAS | 300-62-9 |
| CAS (enantiomer) | |
| PubChem CID | 3007 |
| InChIKey | KWTSXDURSIMDCE-UHFFFAOYSA-N |
| InChI | InChI=1S/C9H13N/c1-8(10)7-9-5-3-2-4-6-9/h2-6,8H,7,10H2,1H3 |
| SMILES | CC(CC1=CC=CC=C1)N |
Synonyms
- Amfetamine
- DL-amphetamine
- Benzedrine
- Alpha-methylphenethylamine
- Speed
- Phenamine
- Whizz
- Billy
- Uppers
Pharmacodynamics & Biochemistry
Amphetamine is a monoamine releaser (a transporter 'substrate'), not a reuptake blocker: it is carried into neurons by the noradrenaline, dopamine and (weakly) serotonin transporters and triggers reverse transport, driving these neurotransmitters out into the synapse. It releases noradrenaline most potently, dopamine next, and serotonin only weakly (NET > DAT >>> SERT). Inside the neuron it is a VMAT2 substrate that disrupts vesicular storage, shifting monoamines out of vesicles into the cytosol (a weak-base/pH effect) where they become available for release: amplifying the rise in synaptic dopamine and noradrenaline. It is also a TAAR1 agonist. TAAR1 activation modulates transporter trafficking and dampens monoamine-neuron firing, a feedback mechanism that shapes the effects of releasers and distinguishes them from pure reuptake blockers.
Biological targets
- NET
- DAT
- SERT
- VMAT2
- TAAR1
Binding & functional measurements
| Target | Measurement | Species |
|---|---|---|
| Noradrenaline transporter | EC50 22 nM | Rat |
| Dopamine transporter | EC50 13 nM | Rat |
| Serotonin transporter | EC50 4,009 nM | Rat |
| 5-HT1A receptor | Ki 6,740 ± 1,380 nM | Human |
| Dopamine transporter | EC50 1,760 nM | Human |
| Dopamine transporter | Ki 640 ± 140 nM | Human |
| Dopamine transporter | Ki 560 ± 110 nM | Mouse |
| Noradrenaline transporter | Ki 70 ± 10 nM | Human |
| Noradrenaline transporter | Ki 120 ± 20 nM | Mouse |
| TAAR1 | Ki 90 ± 60 nM | Mouse |
| TAAR1 | Ki 230 ± 180 nM | Rat |
| α2-adrenoceptor | Ki 2,800 ± 800 nM | Human |
Pharmacokinetics
| Bioavailability | High (oral) |
| Tmax | ≈3 h (IR), ≈7 h (XR) |
| Half-life | ≈9–12 h typical (isomer- and urine pH–dependent) |
| Vd | ≈4 L/kg |
| Protein binding | <20% |
| Metabolism | Extensive hepatic oxidation (notably CYP2D6) + oxidative deamination. Active 4‑hydroxyamphetamine |
| Excretion | Primarily renal. Clearance increases with acidic urine (pH dependent) |
Toxicology & Safety
Harm-reduction note: Toxicity and risk depend on dose, route, purity, combinations, setting, and individual
health factors. Missing harms should never be interpreted as evidence of safety.
≈100 mg/kg (rat, i.p., literature varies)
Amphetamine is a potent CNS stimulant with real medical uses (ADHD, narcolepsy) but a significant potential for tolerance, dependence and misuse. Acutely it raises heart rate, blood pressure and body temperature. Overdose or high recreational doses can cause dangerous hypertension, arrhythmia, hyperthermia, seizures and, with bingeing, stimulant psychosis (paranoia, hallucinations). Repeated high-dose use leads to dependence, a depleting 'comedown', sleep loss, weight loss and mental-health problems. The cardiovascular risk is greater with pre-existing heart disease and multiplies when combined with other stimulants. MAOIs are contraindicated (hypertensive crisis). Illicit 'speed' is of variable and usually low purity and is often adulterated, so dose is unpredictable. Urine pH strongly affects clearance (acidic urine speeds excretion, alkaline prolongs it). Should not be combined with other stimulants, MAOIs or used in pregnancy.[6][5]
Legal Status
Legal note: Legal status can change over time and may vary by country, region, formulation, analogue status,
prescription context, and enforcement practice. Always confirm with current official sources before relying on this section.
US: Schedule II. UK: Class B. DE: BtMG Anlage III (BtM-Rx)
Interactions & Contraindications
Drug interactions
MAOIs Risk of hypertensive crisis and serotonin toxicity, contraindicated including within 14 days of stopping an MAOI.[6]
Stimulants (amphetamines, cocaine) Additive cardiovascular strain and psychosis risk with other sympathomimetics (cocaine, other amphetamines, decongestants).[6]
SSRIs, SNRIs Serotonin-toxicity risk.[6]
Urinary acidifiers or alkalinisers Change clearance, acidic urine speeds excretion and alkaline urine prolongs it.[5]
Contraindications
Cardiovascular disease, hypertension or arrhythmia structural cardiac abnormalities or moderate-to-severe hypertension.[6]
Hyperthyroidism
Concurrent MAOI, SSRI/SNRI or other serotonergic medication concurrent or recent (within 14 days) MAOI use.[6]
Personal or family history of psychosis, schizophrenia or bipolar disorder[6]
History of stimulant or substance use disorder
Closed-angle glaucoma[6]
Pregnancy or breastfeeding
No interactions or contraindications listed.
Usage & Context
- A licensed medicine for ADHD and narcolepsy (e.g. Adderall, Evekeo), and a long-standing recreational stimulant ('speed').
- Illicit street amphetamine is typically a low-purity powder or paste, often heavily adulterated.
- Also used as a forensic/toxicology reference standard.
Sources & Evidence
- PubChem: Amphetamine (CID 3007) — identifiers & computed properties
- IUPHAR/BPS Guide to PHARMACOLOGY: amphetamine (ligand 4804) — targets (NET/DAT/SERT, TAAR1) CC BY-SA 4.0
- Rothman RB, Baumann MH, Dersch CM, et al. (2001). Amphetamine-type central nervous system stimulants release norepinephrine more potently than they release dopamine and serotonin. Synapse 39:32-41.
PMID 11071707 · doi:10.1002/1098-2396(20010101)39:1<32::AID-SYN5>3.0.CO;2-3
- Bunzow JR, Sonders MS, Arttamangkul S, et al. (2001). Amphetamine, 3,4-methylenedioxymethamphetamine, lysergic acid diethylamide, and metabolites of the catecholamine neurotransmitters are agonists of a rat trace amine receptor. Mol Pharmacol 60:1181-8.
PMID 11723224 · doi:10.1124/mol.60.6.1181
- de la Torre R, Farré M, Navarro M, et al. (2004). Clinical pharmacokinetics of amfetamine and related substances: monitoring in conventional and non-conventional matrices. Clin Pharmacokinet 43:157-85.
PMID 14871155 · doi:10.2165/00003088-200443030-00002
- FDA label: EVEKEO (amphetamine sulfate) — dosing, pharmacokinetics, warnings & interactions
- DEA Diversion Control Division: Controlled Substance Schedules (amphetamine — Schedule II)
- Anlage III BtMG (Betäubungsmittelgesetz), gesetze-im-internet.de: amphetamine is listed in Anlage III (verkehrs- und verschreibungsfähig, BtM-Rezept)
- Fitzgerald LR, Gannon BM, Walther D, et al. (2024). Structure-activity relationships for locomotor stimulant effects and monoamine transporter interactions of substituted amphetamines and cathinones. Neuropharmacology 245:109827.
PMID 38154512 · doi:10.1016/j.neuropharm.2023.109827
- Simmler LD, Buser TA, Donzelli M, et al. (2013). Pharmacological characterization of designer cathinones in vitro. Br J Pharmacol 168:458-70.
PMID 22897747 · doi:10.1111/j.1476-5381.2012.02145.x
- Han DD, Gu HH (2006). Comparison of the monoamine transporters from human and mouse in their sensitivities to psychostimulant drugs. BMC Pharmacol 6:6.
PMID 16515684 · doi:10.1186/1471-2210-6-6