THE FAMILY COMPARISON
Carphedon vs piracetam: one phenyl ring, a different pharmacology
Carphedon exists because someone added a phenyl ring to piracetam. This page maps the family tree, the real differences, and the claims that outrun the evidence — including the human head-to-head trial that does not exist.
The racetam family tree
Piracetam (UCB-6215) is the parent: synthesised at UCB in Belgium and championed by Corneliu Giurgea, who coined the word “nootropic” for it. The family shares the 2-oxo-1-pyrrolidine acetamide scaffold. The standard survey divides it into three subgroups: the human-use nootropics (piracetam, oxiracetam, aniracetam, pramiracetam, phenylpiracetam), the SV2A antiepileptics (levetiracetam, seletracetam, brivaracetam), and the nefiracetam branch. Phenylpiracetam is the 4-phenyl analogue of the parent — a beta-substituted GABA derivative by structure.[12][13][35]
Side by side
| DIMENSION | PIRACETAM | CARPHEDON (PHENYLPIRACETAM) |
|---|---|---|
| Structure | 2-oxo-1-pyrrolidine acetamide — the parent scaffold | Same scaffold + phenyl ring at the 4-position |
| Stereochemistry | No stereocentre | One stereocentre (C4); sold as the racemate |
| Documented target pharmacology | No high-affinity receptor found in classic screening | R-enantiomer: DAT inhibition (IC50 4.82 µM); α4β2 nAChR binding (5.86 µM) |
| Stimulant character | Absent | Present — the DAT pharmacology behind the WADA listing |
| Human evidence | Large but null-leaning: Cochrane found no support in dementia/cognitive impairment | Small and single-country: one mixed RCT, large open Russian studies |
| Sport status | Not listed | WADA S6.A non-specified stimulant since 1998 — the only racetam listed |
| Regulatory reach | Widely sold; drug or supplement by jurisdiction | Prescription-only in Russia; unauthorised in the EU/Australia; unapproved in the US |
Sources: the family survey, the DAT pharmacology papers, the Cochrane review, the WADA list and the regulatory surveillance record.[12][8][25][28][27]
The “more potent” claim — and what actually supports it
The standard survey states it plainly: “phenylpiracetam is more potent than piracetam and is used for a wider range of indications.” The direct comparison that exists is animal work: in experimental cerebral ischemia, phenylpiracetam outperformed piracetam on function retention, survival and cerebral-flow restoration. What does not exist is a published head-to-head human trial — the potency claim rests on animal data and Russian open studies, and this site says so wherever it repeats it.[12][40]
The family shadow: piracetam’s own large evidence base failed the Cochrane test in dementia and cognitive impairment — effects on global impression, no benefit on specific measures. The same review tradition has never been applied to carphedon, because the controlled-trial base to review does not exist. A bigger claim inherited from a null family is still a claim awaiting its test.[25]
The carphedon branch keeps growing
The molecule has its own documented analogue family: RGPU-95 (4-chlorophenylpiracetam), reported at 5–10× potency in Russian preclinical work; phenylpiracetam hydrazide, described as anticonvulsant in secondary sources; and the methylphenylpiracetam stereoisomers, one of which — (4R,5S)-E1R — emerged as a sigma-1 positive allosteric modulator with its own research trajectory. Mainstream synthetic chemistry, meanwhile, used phenotropil as a demonstration target three times in 2026 alone.[42][43][37][38][39]
Family position, one sentence: carphedon is the racetam that crossed into stimulant pharmacology — and paid for it with a 1998 WADA listing the rest of the family never earned.