Racetam Comparison 2026: Piracetam vs Aniracetam vs Oxiracetam vs Phenylpiracetam vs Pramiracetam vs Coluracetam vs Fasoracetam vs Sunifiram vs Unifiram (+ Fonturacetam Hydrazide)
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The Complete Racetam Comparison & Decision Guide (2026)

Piracetam vs Aniracetam vs Oxiracetam vs Phenylpiracetam vs Pramiracetam vs Coluracetam vs Fasoracetam vs Sunifiram vs Unifiram, plus Fonturacetam Hydrazide - side by side on CAS, molecular formula, mechanism of action, typical dose, half-life, solubility and which one actually fits your research question. Built for researchers who need accurate, citable data, not marketing hype.

Jump to comparison table Which one should I pick?
⚠️ Research-use only — read before you cite or order. Every compound compared on this page is a research-grade reference material supplied "for laboratory use only." None are approved as foods, dietary supplements or medicines by the FDA, EMA or any other agency, and none are intended for human or veterinary consumption. Researchers are solely responsible for confirming legality, import/export controls and permissible use under all applicable local, national and international laws before procurement or handling. This article is educational and is not medical, dosing or legal advice.
🧪

Parent molecule

Piracetam (CAS 7491-74-9) is the 1964 prototype; every other entry here is a structural derivative or a related ampakine.

⚡

Most potent

Sunifiram & Unifiram (ampakines) - ~1,000x piracetam per mg, dosed at 1-10 mg/day.

🩷

Stimulant-like

Phenylpiracetam - only racetam with clear dopaminergic drive; 100-200 mg/day.

🔮

Different mechanism

Coluracetam boosts choline uptake; Fasoracetam targets mGluR/GABA-B - not classic racetam pharmacology.

What are racetams, and why compare them?

Racetams are a family of synthetic 2-pyrrolidone (cyclic GABA) derivatives that share a pyrrolidone core and a substituted amide side chain. The class began in 1964 when Corneliu Giurgea at UCB synthesized piracetam and coined the term "nootropic" ("towards the mind"). What makes them interesting to neurochemistry researchers is that, unlike stimulants, they are not strongly psychoactive on their own - they appear to modulate neurotransmission (acetylcholine, glutamate/AMPA, membrane fluidity) rather than force it.

This guide compares the ten most-discussed members you will encounter in the literature and in procurement catalogs. Nine are true racetams; Sunifiram and Unifiram are included because they were developed as ampakine simplifications of the racetam scaffold and are almost always benchmarked against piracetam. Fonturacetam Hydrazide (CAS 77472-71-0) - the hydrazide derivative of phenylpiracetam, also encountered in catalogs as "phenylpiracetam hydrazide" - is presented throughout by its verified research name.

Accuracy note: CAS numbers, molecular formulas and molecular weights below are verified against Wikipedia, PubChem, CAS Common Chemistry and supplier datasheets (Selleck, BOC Sciences). Typical doses, half-lives and "potency" figures are literature/community-reported research values, not clinical dosing recommendations. Potency and pharmacokinetics vary by route, species and model. Always confirm identity and purity against your supplier's Certificate of Analysis (COA) before any experimental use.

Side-by-side comparison table

The single reference most people bookmark and share. Sort by what matters to your study - mechanism, dose, or legal status.

Compound CAS Formula MW Primary mechanism Typical research dose Half-life Solubility Relative potency Best-fit research use Status*
Piracetam 7491-74-9 C6H10N2O2 142.16 Membrane fluidity; cholinergic & AMPA support 1.2-4.8 g/day ~4-5 h High (water) 1x (baseline) Cognitive impairment, vertigo, general neuroprotection Rx (EU)
Aniracetam 72432-10-1 C12H13NO3 219.24 AMPA PAM (partial); anxiolytic 750-1500 mg/day (split) ~1-2.5 h Lipophilic Moderate Anxiety, mood, social cognition Research/Rx
Oxiracetam 62613-82-5 C6H10N2O3 158.16 Cholinergic; NMDA; mildly stimulating 800-2400 mg/day ~8 h High (water) Mod-High Attention, stimulating cognition Research/Rx
Phenylpiracetam 77472-70-9 C12H14N2O2 218.25 Dopamine/NE + cognition; cold-resistance 100-200 mg/day ~3-5 h Lipophilic High Stimulant-like drive, performance, attention Rx (RU)
Pramiracetam 68497-62-1 C14H27N3O2 269.38 Cholinergic (memory/attention) 300-1200 mg/day ~5 h Lipophilic High Memory, sustained attention Research
Coluracetam 135463-81-9 C19H23N3O3 341.41 HACU - high-affinity choline uptake 10-80 mg/day ~8 h Lipophilic (H2O ~0.4 mg/mL) Very high Depression/GAD + cognition; cholinergic deficit S4 (AU)
Fasoracetam 110958-19-5 C10H16N2O2 196.25 mGluR modulator; GABA-B antagonist 100-400 mg/day 4-6.5 h Lipophilic Moderate GABA-B withdrawal, mGluR-related work S4 (AU)
Sunifiram 314728-85-3 C14H18N2O2 246.31 Ampakine - AMPA/NMDA glycine site 1-10 mg/day ~2-3 h Lipophilic Extreme (~1000x) High-potency learning/memory Research
Unifiram 272786-64-8 C13H15FN2O3S 298.33 Ampakine - AMPA/NMDA glycine site 1-10 mg/day Short Lipophilic Extreme (~1000x) High-potency cognition (sunifiram analogue) Research
Fonturacetam Hydrazide 77472-71-0 C12H15N3O2 233.27 Hydrazide analogue; anticonvulsant; neuroprotect Research values only - Mod-Lipophilic Mod-High Anticonvulsant, neuroprotection Research

*Status is indicative and varies by jurisdiction: Rx = prescription drug; S4 (AU) = Australian Schedule 4 prescription-only; Research = unscheduled research chemical. Confirm current local regulation before procurement. "Potency" is relative to piracetam in preclinical cognition models and is not a clinical efficacy ranking.

Two mechanism families you must separate

Nearly all confusion in racetam debates comes from lumping two different pharmacological classes together. Here is the clean split:

🧪 Racetams (2-pyrrolidone core)

Share the pyrrolidone backbone. They modulate rather than flood neurotransmission - improving membrane dynamics, acetylcholine availability and AMPA/NMDA signalling. Effects are subtle per dose and build over days. Includes Piracetam, Aniracetam, Oxiracetam, Phenylpiracetam, Pramiracetam, Coluracetam, Fasoracetam and Fonturacetam Hydrazide.

PiracetamAniracetamOxiracetamPhenylpiracetamPramiracetamColuracetamFasoracetamPPH

⚡ Ampakines (piperazine core)

Sunifiram (DM-235) and Unifiram (DM-232) are piperazine-derived ampakines, not pyrrolidones. They drive AMPA receptor function (and the NMDA glycine site) far more directly, which is why they are orders of magnitude more potent and act within minutes. They have never entered human clinical trials - a key caveat for any comparison.

SunifiramUnifiram

Compound-by-compound breakdown

Piracetam Rx (EU)

CAS 7491-74-9 · C6H10N2O2 · 142.16 g/mol
Mechanism: Increases neuronal membrane fluidity and supports cholinergic/AMPA signalling without binding a single receptor tightly. The reference standard every other racetam is measured against.
Typical dose1.2-4.8 g/day
Half-life~4-5 h
SolubilityHighly water-soluble
Research useCognitive impairment, vertigo, myoclonus, general neuroprotection

Aniracetam Research/Rx

CAS 72432-10-1 · C12H13NO3 · 219.24 g/mol
Mechanism: Partial positive allosteric modulator at AMPA receptors - the structural base for its anxiolytic and pro-social profile. Fat-soluble, short-acting.
Typical dose750-1500 mg/day, split
Half-life~1-2.5 h (short)
SolubilityLipophilic
Research useAnxiety, mood, social/contextual cognition

Oxiracetam Research/Rx

CAS 62613-82-5 · C6H10N2O3 · 158.16 g/mol
Mechanism: Closer to piracetam but with a mild stimulant edge; supports cholinergic and NMDA signalling. Water-soluble and longer-acting than aniracetam.
Typical dose800-2400 mg/day
Half-life~8 h
SolubilityHighly water-soluble
Research useAttention, mildly stimulating cognition

Phenylpiracetam Rx (RU)

CAS 77472-70-9 · C12H14N2O2 · 218.25 g/mol
Mechanism: Phenyl substitution adds clear dopaminergic/noradrenergic stimulant activity plus cold-resistance - the only racetam with obvious "drive." Developed in Russia; used by cosmonauts in lore.
Typical dose100-200 mg/day (low)
Half-life~3-5 h
SolubilityLipophilic
Research useStimulant-like performance, attention, cold exposure

Pramiracetam Research

CAS 68497-62-1 · C14H27N3O2 · 269.38 g/mol
Mechanism: High-affinity cholinergic modulator emphasising memory and sustained attention; reported as one of the more potent classic racetams per dose.
Typical dose300-1200 mg/day
Half-life~5 h
SolubilityLipophilic
Research useMemory consolidation, long-focus tasks

Coluracetam S4 (AU)

CAS 135463-81-9 · C19H23N3O3 · 341.41 g/mol
Mechanism: Enhances high-affinity choline uptake (HACU) - the rate-limiting step of acetylcholine synthesis - rather than binding receptors. Potent at 10-80 mg/day; investigated for depression/GAD with cholinergic deficit.
Typical dose10-80 mg/day
Half-life~8 h
SolubilityLipophilic (H2O ~0.4 mg/mL)
Research useCholinergic deficit, MDD/GAD comorbidity

Fasoracetam S4 (AU)

CAS 110958-19-5 · C10H16N2O2 · 196.25 g/mol
Mechanism: Modulates all three groups of metabotropic glutamate receptors (mGluR) and antagonises GABA-B receptors - useful when studying GABA-B down-regulation (e.g. post-benzodiazepine models).
Typical dose100-400 mg/day
Half-life4-6.5 h
SolubilityLipophilic
Research useGABA-B withdrawal, mGluR-mutation ADHD models

Sunifiram Research

CAS 314728-85-3 · C14H18N2O2 · 246.31 g/mol
Mechanism: Piperazine ampakine (DM-235). Drives AMPA function and the NMDA glycine site; reverses scopolamine/baclofen amnesia in rodents at ~0.001 mg/kg. No human trials.
Typical dose1-10 mg/day
Half-life~2-3 h (short)
SolubilityLipophilic
Research useHigh-potency learning/memory, LTP

Unifiram Research

CAS 272786-64-8 · C13H15FN2O3S · 298.33 g/mol
Mechanism: Piperazine ampakine (DM-232), the structural parent simplified from sunifiram. Same AMPA/NMDA glycine-site direction; extreme potency per mg, no clinical data.
Typical dose1-10 mg/day
Half-lifeShort
SolubilityLipophilic
Research useHigh-potency cognition, SAR of ampakines

Fonturacetam Hydrazide Research

CAS 77472-71-0 · C12H15N3O2 · 233.27 g/mol
Mechanism: Hydrazide analogue of phenylpiracetam (fonturacetam hydrazide). First reported 1980 as an anticonvulsant (electroshock ED50 ~310 mg/kg); weaker direct cognition boost than phenylpiracetam but stronger neuroprotection.
Typical doseResearch values only
Half-lifeNot established
SolubilityMod-Lipophilic
Research useAnticonvulsant, neuroprotection studies

Stacking and the choline question

A recurring theme in racetam research is pairing them with a choline source (Alpha-GPC or CDP-choline). The rationale: racetams increase acetylcholine turnover, so if dietary choline is limiting, some users report headaches. The evidence is anecdotal rather than clinical, but the combination is standard in the literature-surveying community - especially with Piracetam, Oxiracetam, Pramiracetam and Coluracetam (which targets choline uptake directly).

  • Cholinergic stack: Piracetam or Oxiracetam + Alpha-GPC/CDP-choline for attention and memory models.
  • Stimulant stack: Low-dose Phenylpiracetam for drive, paired with a calmer racetam (Aniracetam) for mood.
  • Potency caution: Sunifiram/Unifiram are dosed in single-digit mg - volumetric dosing in DMSO/ethanol is typical; do not scale by racetamgram intuition.
  • GABA recovery: Fasoracetam is studied specifically for GABA-B down-regulation models, not as a general daily stack.
Compliance: All compounds above are research-grade chemicals supplied "for laboratory use only" by reputable vendors. They are not approved as foods, supplements or medicines in most jurisdictions, and none of the stacking notes above constitute medical or dosing advice.

Which racetam should I pick? (by research goal)

A quick map from question to compound. This is a navigation aid for study design, not a recommendation.

⚠️ Regulatory status differs by jurisdiction (see Legal & Regulatory Disclaimer below). Verify the compound is permitted for your intended research before ordering.

Memory & long focus
Pramiracetam / Piracetam

Cholinergic bias, clean memory consolidation without stimulant sides.

Anxiety & mood
Aniracetam

AMPA partial-agonism gives the clearest anxiolytic/social signal.

Drive & performance
Phenylpiracetam

Only racetam with dopaminergic stimulant-like activity; low daily dose.

Depression / GAD + cognition
Coluracetam

HACU up-regulation targets cholinergic deficit underlying comorbid MDD/GAD.

GABA-B / mGluR models
Fasoracetam

mGluR modulation + GABA-B antagonism for withdrawal/down-regulation studies.

Max potency / LTP
Sunifiram / Unifiram

Ampakines, ~1000x piracetam potency; pre-clinical cognition only.

Anticonvulsant
Fonturacetam Hydrazide

Original 1980 indication; ED50 ~310 mg/kg electroshock.

Benchmark / control
Piracetam

The reference standard - use as the comparator in any racetam study.

Stimulating attention
Oxiracetam

Water-soluble, longer half-life, mild stimulant edge over piracetam.

Frequently Asked Questions

High-traffic questions about racetam potency, choline, legality and mechanism - with sourced, citable answers.

What is the strongest racetam?
By mass, the ampakine-class agents Sunifiram (DM-235) and Unifiram (DM-232) are the most potent - reported to be roughly 1,000x (and in some preclinical amnesia models up to ~10,000x) more potent than piracetam per unit mass, effective at 1-10 mg/day. Among true racetams, Phenylpiracetam is used at the lowest dose (100-200 mg/day) and Coluracetam at just 10-80 mg/day because both are high-potency. "Strongest" depends on the endpoint: Sunifiram/Unifiram for raw cognition potency, Phenylpiracetam for stimulant-like drive, Pramiracetam for memory.
Do racetams need a choline source?
Many researchers combine racetams with a choline source (e.g. Alpha-GPC or CDP-choline) on the theory that increased acetylcholine turnover can cause headaches if choline is limiting. The evidence is anecdotal, but the practice is common especially with Piracetam, Oxiracetam, Pramiracetam and Coluracetam (which targets choline uptake directly). It is not a clinically established requirement. All compounds discussed here are research-grade chemicals for laboratory use only, not approved human supplements.
What is the difference between Piracetam and Aniracetam?
Piracetam is the parent 2-pyrrolidone, highly water-soluble, taken at gram doses (1.2-4.8 g/day) and thought to work mainly through membrane fluidity and general cholinergic/AMPA support. Aniracetam is a fat-soluble ester derivative that is a partial positive allosteric modulator at AMPA receptors, giving it pronounced anxiolytic and mood/social effects; it is taken at 750-1500 mg/day but has a very short half-life (~1-2.5 h) so it is usually dosed multiple times per day.
Are racetams legal?
Status varies by country. Piracetam is a prescription drug in much of Europe. Phenylpiracetam is a prescription stimulant in Russia. In the United States, racetams are not FDA-approved drugs and are sold as unscheduled "research chemicals" or "not for human consumption" powders; the FDA has objected to piracetam being sold in dietary supplements. Australia schedules several (e.g. Coluracetam, Fasoracetam) as S4 prescription-only. Researchers must follow their local regulations; this page is informational only.
Is Sunifiram a racetam?
No. Sunifiram (DM-235) and Unifiram (DM-232) are piperazine-derived ampakines, not 2-pyrrolidone racetams. They are included in racetam comparison guides because they were developed as structural simplifications of piracetam-like cognition enhancers and act on the same AMPA/NMDA synaptic-plasticity pathways. They are far more potent and, unlike the racetams, have never entered human clinical trials.
What is Fonturacetam Hydrazide and how does it differ from Phenylpiracetam?
Fonturacetam Hydrazide (also called fonturacetam hydrazide, CAS 77472-71-0) is a hydrazide analogue of Phenylpiracetam in which the terminal amide is replaced by a hydrazide group (-CONHNH2). It was first reported by a Soviet group in 1980 as an anticonvulsant (electroshock ED50 ~310 mg/kg). Compared with Phenylpiracetam it shows weaker direct cognition enhancement but a stronger neuroprotective/anticonvulsant profile and is studied as a research chemical, not a marketed drug.
Which racetam is best for anxiety vs memory vs focus?
Anxiolytic/social: Aniracetam. Memory and long-term focus: Pramiracetam and Piracetam. Stimulant-like drive, cold resistance and attention: Phenylpiracetam. Depressive/anxious cognition with cholinergic deficit: Coluracetam. GABA-withdrawal or mGluR-related work: Fasoracetam. Raw learning/memory potency: Sunifiram or Unifiram. These are research directions, not medical recommendations.
How long do racetams take to work?
Classic racetams are modulators, not stimulants - subjective effects in studies are often subtle and accumulate over days to weeks of daily use rather than appearing in minutes. By contrast the ampakines Sunifiram/Unifiram act on AMPA receptors much faster (within the session in preclinical models) because they more directly drive excitatory transmission. Pharmacokinetics also differ: Aniracetam clears in ~1-2.5 h while Oxiracetam and Coluracetam last ~8 h.

Legal & Regulatory Disclaimer

  • Not approved drugs. Piracetam, Aniracetam, Oxiracetam, Phenylpiracetam, Pramiracetam, Coluracetam, Fasoracetam, Sunifiram, Unifiram and Fonturacetam Hydrazide are not approved by the FDA/EMA as pharmaceuticals, foods or supplements. They are sold as unscheduled "research chemicals" with a "not for human consumption" label in many markets.
  • Status varies by country. Piracetam is prescription-only across much of Europe; Phenylpiracetam is a prescription stimulant in Russia; Australia schedules Coluracetam and Fasoracetam as S4 (prescription-only); the U.S. leaves most unscheduled but the FDA has objected to piracetam in dietary supplements. Check current law in your jurisdiction.
  • Import / export & control. Cross-border movement of chemicals may trigger controls (precursor, stimulant or analogue legislation). The buyer/researcher assumes all responsibility for lawful import, storage and disposal.
  • No medical or dosing advice. Doses, half-lives and potency figures are literature/community-reported research values, not clinical recommendations. Nothing here diagnoses, treats or prevents any condition.
  • Intellectual property. Compound, use and formulation patents may apply in some regions; verify freedom-to-operate for any commercial application.
Bottom line: treat all ten compounds as regulated research materials. Confirm local legality and obtain a supplier COA before any experimental work.
Disclaimer: This article is an educational, literature-based comparison for researchers and is not medical, dosing or legal advice. Compound status, doses and potency figures change with jurisdiction and new data; verify against current regulatory sources and your supplier's COA. Nutrabiotech Chem supplies research-grade reference materials "for laboratory use only."

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