Piracetam
2-(2-oxopyrrolidin-1-yl)acetamide
Overview
Piracetam belongs to Nootropics.
Effects
- Piracetam produces subtle effects and is generally non-intoxicating: trials and users report modest improvements in aspects of memory, attention and processing, most consistently in people with age-related decline, dementia or post-hypoxic states rather than in healthy young adults, where the evidence is weak and inconsistent.
- It is neither sedating nor stimulating and does not produce euphoria. There is no recognised recreational 'high'. When unwanted psychological effects occur they are usually over-activation, nervousness, agitation, irritability, anxiety or insomnia, rather than intoxication.
- Any subjective effect has a slow, mild onset. Because piracetam is low-potency, very large single doses mainly add side effects rather than proportionally greater benefit.
Dosing & duration
Oral (tablets, capsules or oral solution). Parenteral formulations exist for hospital use. Piracetam is used essentially only orally.. Piracetam is not a recreational drug. It is not meaningfully euphoric and has no accepted 'recreational' dose. The figures below are therapeutic/clinical reference ranges from the medical literature, not a recommendation. Clinical doses are high (grams, not milligrams) because piracetam is low-potency, and are divided across the day. Doses must be reduced in renal impairment, because piracetam is cleared unchanged by the kidneys.
Dose ranges
1.2–2.4 g/day
2.4–4.8 g/day, divided
7.2–24 g/day
Duration
≈30–60 minutes (oral)
Plasma half-life ≈4–5 h, clinical benefit is assessed over days to weeks, not per dose
No recognised comedown or withdrawal syndrome. Not associated with dependence
Chemical & Physical Properties
| Formula | C6H10N2O2 |
| Molar mass | 142.16 g/mol |
| State | Solid (crystalline) |
| Melting point | 151.5–152.5 °C |
| Boiling point | Decomposes |
| Density | Not reported |
| Vapor pressure | Not reported |
| pKa | Not reported |
| LogP | -1.54 (log Kow, experimental) |
| Solubility | Not reported |
| Refractive index | Not reported |
Identifiers & Synonyms
| CAS | 7491-74-9 |
| CAS (enantiomer) | |
| PubChem CID | 4843 |
| InChIKey | GMZVRMREEHBGGF-UHFFFAOYSA-N |
| InChI | InChI=1S/C6H10N2O2/c7-5(9)4-8-3-1-2-6(8)10/h1-4H2,(H2,7,9) |
| SMILES | C1CC(=O)N(C1)CC(=O)N |
Synonyms
- Nootropil
Pharmacodynamics & Biochemistry
Piracetam is the prototypical 'racetam' nootropic, a cyclic derivative of the neurotransmitter GABA, but it has essentially no direct GABAergic, sedative or stimulant activity and is not appreciably intoxicating. Its cellular mechanism is still only partly understood and is generally described as modulatory rather than acting through a single high-affinity receptor. The best-characterised molecular action is positive allosteric modulation of AMPA-type ionotropic glutamate receptors: the IUPHAR/BPS Guide to PHARMACOLOGY lists piracetam as a positive allosteric modulator at all four human AMPA-receptor subunits (GluA1–GluA4). By slowing receptor desensitisation it is thought to enhance AMPA-mediated excitatory (glutamatergic) neurotransmission: the 'ampakine'-like action it shares with aniracetam. This modulation is weak and no quantitative affinity or potency values are reported, so no binding table is shown below. Piracetam also has membrane-level effects: it interacts with the polar head groups of membrane phospholipids and is proposed to restore membrane fluidity, which may improve neuronal signalling, mitochondrial function and the mobility of receptors and neurotransmitters: an effect invoked to explain its broad, non-specific actions in ageing and hypoxic tissue. A separate, clinically important action is haemorheological: piracetam reduces platelet aggregation and red-blood-cell adhesion to vascular endothelium and improves erythrocyte deformability and microcirculation. This antithrombotic/rheological effect underlies its use in cortical myoclonus and vascular indications, and is also the reason for its bleeding-related cautions.
Biological targets
- AMPA
Binding & functional measurements
Pharmacokinetics
| Bioavailability | Oral ≈100% (rapid, complete absorption), not bound to plasma proteins |
| Tmax | ≈0.5–1 h (fasting) |
| Half-life | ≈4–5 h (plasma), ≈8.5 h in CSF |
| Vd | Not reported |
| Protein binding | Not reported |
| Metabolism | Not metabolised (no known metabolites) |
| Excretion | Renal, excreted unchanged (~80–100% recovered in urine). Crosses the blood–brain barrier and placenta |
Toxicology & Safety
Not reported
Piracetam has an exceptionally favourable safety and tolerability profile: acute toxicity is very low, it is not sedating or respiratory-depressant, and it is not associated with dependence, addictive tolerance or a withdrawal syndrome: a sharp contrast to the sedative-hypnotics. Adverse effects are uncommon and are usually mild over-stimulation: nervousness, agitation, irritability, anxiety, insomnia, and occasionally headache, weight gain, somnolence or gastrointestinal upset. Its main practical cautions come from its antiplatelet action (bleeding risk: cerebral haemorrhage, surgery, anticoagulant co-use) and its renal clearance (dose reduction in renal impairment). Note that in the United States piracetam is neither an approved drug nor a lawful dietary-supplement ingredient, yet it is sold in unregulated 'nootropic' products of uncertain dose and purity.[4][5][6]
Legal Status
US: Not approved / not scheduled. UK: Prescription-only medicine (POM). DE: Prescription only (Rx)
Interactions & Contraindications
Drug interactions
Contraindications
No interactions or contraindications listed.
Usage & Context
- The prototypical racetam nootropic and a licensed medicine across much of Europe (Nootropil and others), used for age-related cognitive decline, dementia, vertigo and, at high doses, cortical myoclonus. The evidence of benefit is strongest in older people and in post-hypoxic or vascular states.
- One of the most widely used 'smart drugs' sold online for off-label cognitive enhancement, despite weak and inconsistent evidence in healthy people. In the United States it is sold in unapproved supplements rather than as a medicine.
Sources & Evidence
- PubChem: Piracetam (CID 4843) — identifiers & computed properties
- IUPHAR/BPS Guide to PHARMACOLOGY: piracetam (ligand 4288) — positive allosteric modulator at AMPA receptor subunits GluA1–GluA4 CC BY-SA 4.0
- Ahmed AH, Oswald RE (2010). Piracetam defines a new binding site for allosteric modulators of alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors. J Med Chem 53:2197-203.
PMID 20163115 · doi:10.1021/jm901905j
- Winblad B (2005). Piracetam: a review of pharmacological properties and clinical uses. CNS Drug Rev 11:169-82.
PMID 16007238 · doi:10.1111/j.1527-3458.2005.tb00268.x
- Malykh AG, Sadaie MR (2010). Piracetam and piracetam-like drugs: from basic science to novel clinical applications to CNS disorders. Drugs 70:287-312.
PMID 20166767 · doi:10.2165/11319230-000000000-00000
- Cohen PA, Zakharevich I, Gerona R (2020). Presence of Piracetam in Cognitive Enhancement Dietary Supplements. JAMA Intern Med 180:458-459.
PMID 31764936 · doi:10.1001/jamainternmed.2019.5507
- Wikipedia: Piracetam (pharmacology, pharmacokinetics & legal status) CC BY-SA 4.0
- DrugCentral: piracetam (2197) — approved-drug pharmacology record