Coluracetam
Cognition, Visual Processing
No human half-life has been published. Originally developed as MKC-231 and taken into clinical study for depression, but pharmacokinetic detail is not in the accessible literature.
In short
- Originally MKC-231, developed in Japan for Alzheimer disease and later trialled for major depressive disorder.
- Its mechanism is distinctive: it enhances high-affinity choline uptake rather than acting on receptors directly.
- Reached phase 2 in treatment-resistant depression, where it did not meet its primary endpoint.
- No human half-life has been published.
- Anecdotal reports of altered visual perception are unusual for the class and remain unexplained.
Structure
How it works
Coluracetam enhances high-affinity choline uptake, the rate-limiting step in acetylcholine synthesis. Rather than supplying choline or blocking its breakdown, it increases the efficiency with which cholinergic neurons take choline up for conversion to acetylcholine.
This is mechanistically distinct from the rest of the racetam family and is the reason it is sometimes described as working with rather than around the cholinergic system.
Effects on visual processing reported anecdotally have no established mechanism, though cholinergic signalling does have a role in visual attention.
What the research shows
Preclinical work reported reversal of cholinergic-lesion-induced learning deficits.
The original Alzheimer programme in Japan did not produce approval.
A phase 2a trial in major depressive disorder with comorbid anxiety, conducted by BrainCells Inc, did not meet its primary endpoint, though some subgroup signal was reported.
Cognitive and visual effects in healthy people are anecdotal.
Dosing in the literature
Figures below are quoted from published studies, with the species or population they were measured in. They are records of what was studied, not recommendations.
| Studied in | Amount | Route | Source |
|---|---|---|---|
| Human — phase 2a trial in major depressive disorder | 80 mg three times daily | oral | PubMed |
Commonly reported ranges
These are amounts people report using. They are not from any study, have not been evaluated for safety, and are reproduced here only because they circulate widely and are better seen alongside the evidence than instead of it.
| Reported by | Amount | Route |
|---|---|---|
| Commonly reported | 5–20 mg, one to three times daily | oral or sublingual |
No published human pharmacokinetic study establishes a dose, interval, or duration for this compound. Community figures below have no trial behind them and are reports of practice, not evidence. The trial dose of 240 mg daily is an order of magnitude above typical community use. No human half-life has been published, so dosing intervals in community use are not derived from pharmacokinetics.
Handling and storage
Oral or sublingual, as capsules or powder. Fat solubility is reported, so administration with food is sometimes described.
Without published pharmacokinetics there is no evidence-based dosing interval.
Side effects
The phase 2a trial provides some human safety data at 240 mg daily, with tolerability reported as acceptable.
Community reports mention headache, fatigue, and occasionally the visual effects noted above.
Long-term safety data does not exist.
Combinations
Commonly paired with a choline source (alpha-GPC, citicoline) on the reasoning that racetams increase cholinergic demand and that headache reflects choline depletion. This is a widely repeated community model rather than an established mechanism, and controlled evidence for the pairing is absent.
Research status
Developed as MKC-231 by Mitsubishi Tanabe for Alzheimer disease, then licensed to BrainCells Inc for depression. Phase 2a completed without meeting the primary endpoint.
The preclinical literature on high-affinity choline uptake is genuine; the clinical file is small and negative.
Legal status
Not approved in any jurisdiction. Sold as a research chemical. Does not meet the US definition of a dietary supplement.
WADA status
Not specifically named on the Prohibited List. Falls under WADA class S0, which prohibits any pharmacological substance not currently approved by any governmental regulatory health authority for human therapeutic use. Treat it as prohibited in sport.
Conclusion
Coluracetam has the most mechanistically interesting story of the racetams and a phase 2 result that missed its endpoint.
The frequently reported visual effects are the most distinctive thing users describe and have no established explanation, which is worth holding onto as a reminder that unexplained effects are not automatically benign.
Sources
Track your own Coluracetam protocol
Peppers logs your doses, models your levels from this half-life, tracks your vials and tells you when you will run out. Free on iPhone.
Reference and educational information only. Not medical advice. Nothing here diagnoses, treats, or prescribes, and nothing here is a recommendation to use any compound. The compounds described are research chemicals and are not approved for human consumption. Legal and anti-doping status change — the review date above is when these claims were last checked. Talk to a qualified clinician about anything you intend to take.