Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.
| Alpha-GPC | CDP-Choline (Citicoline) | |
|---|---|---|
| Category | Nootropics | Nootropics |
| Standard Dose | 300-600 mg/day | 250-500 mg/day |
| Timing | Morning or pre-workout. Can be taken with or without food. Split into 1-2 doses. | Morning or split morning/afternoon. With or without food. |
| Cycle Duration | Ongoing; no cycling required for standard doses | Ongoing; no cycling required |
| Evidence Level | strong_human | strong_human |
Highly bioavailable choline source that crosses the blood-brain barrier efficiently via passive diffusion. Serves as a direct precursor for acetylcholine synthesis and phosphatidylcholine, a major structural component of neuronal membranes. Also stimulates growth hormone release via cholinergic activation of GHRH-releasing neurons in the hypothalamus. Contains ~40% choline by weight.
300-600 mg/day
Morning or pre-workout. Can be taken with or without food. Split into 1-2 doses.
Ongoing; no cycling required for standard doses
Prodrug that is hydrolyzed to choline and cytidine upon oral ingestion. Choline supports acetylcholine synthesis and phosphatidylcholine membrane repair. Cytidine is converted to uridine, which enhances synaptic membrane synthesis via the Kennedy pathway and upregulates dopamine receptor density. This dual mechanism — cholinergic support plus dopaminergic modulation — is unique among choline sources.
250-500 mg/day
Morning or split morning/afternoon. With or without food.
Ongoing; no cycling required
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