Quick Comparison

Black Seed OilCiticoline (CDP-Choline)
Half-Life6-8 hours (thymoquinone)56-71 hours (sustained release characteristics)
Typical DosageStandard: 1-3 teaspoons oil daily, or 500-1000 mg standardized extract (minimum 2% thymoquinone). Take with food. Cold-pressed oil retains more bioactives. Taste is peppery/bitter — capsules available for those who dislike the taste.Standard: 250-500 mg daily. Clinical studies use 500-2000 mg daily. Take in the morning — mildly stimulating. Cognizin is the most studied form. Can be split into 2 doses. Often combined with racetams to provide the choline needed for enhanced acetylcholine turnover.
AdministrationOral (oil, softgels, capsules). Cold-pressed oil preferred. Take with food.Oral (capsules, powder). Cognizin branded form is most studied. Take in the morning.
Research Papers9 papers10 papers
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Mechanism of Action

Black Seed Oil

Thymoquinone is the primary bioactive, providing neuroprotection through multiple mechanisms: it scavenges reactive oxygen species (superoxide, hydroxyl radical, peroxynitrite) and upregulates Nrf2/ARE pathway, increasing glutathione (via GCLC, GSS), superoxide dismutase (SOD1/SOD2), and catalase. It inhibits NF-kB by preventing IkB-alpha degradation and blocking p65 nuclear translocation, reducing neuroinflammation and pro-inflammatory cytokine release. Thymoquinone inhibits acetylcholinesterase (AChE) at the peripheral anionic site, increasing synaptic acetylcholine. It modulates GABA-A receptors (positive allosteric modulation at benzodiazepine site), providing anxiolytic effects. Thymoquinone protects neurons from amyloid-beta toxicity by reducing oxidative stress and inhibiting beta-secretase (BACE1). It reduces tau hyperphosphorylation by inhibiting GSK-3beta and CDK5.

Citicoline (CDP-Choline)

Citicoline (CDP-choline) is hydrolyzed in the gut by alkaline phosphatase to choline and cytidine-5'-monophosphate, which are absorbed separately and reassembled in the brain via the Kennedy pathway. Choline feeds two critical pathways: (1) Acetylcholine synthesis via choline acetyltransferase (ChAT) — the primary memory and learning neurotransmitter acting at muscarinic and nicotinic receptors. (2) Phosphatidylcholine synthesis via CTP:phosphocholine cytidylyltransferase — the structural component of neuronal membranes and synaptic vesicles. Cytidine is dephosphorylated to uridine, converted to UTP, and supports RNA synthesis and CDP-choline formation for synapse formation. Citicoline also activates SIRT1 (possibly via NAD+ modulation) and increases brain norepinephrine and dopamine (mechanism unclear — may enhance synthesis or release). It is the only choline source providing both cholinergic and membrane-building support in one molecule.

Risks & Safety

Black Seed Oil

Common

Mild gastrointestinal discomfort, burping.

Serious

May lower blood pressure and blood sugar — caution with relevant medications. May slow blood clotting.

Rare

Allergic reaction, contact dermatitis with topical use.

Citicoline (CDP-Choline)

Common

Headache (especially with racetams — indicates too much cholinergic stimulation), nausea, diarrhea.

Serious

None documented at standard doses.

Rare

Insomnia, blurred vision.

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