Quick Comparison

ALCARBlack Seed Oil
Half-Life4-5 hours6-8 hours (thymoquinone)
Typical DosageStandard: 500-2000 mg daily in 1-2 doses. For cognitive support: 1000-2000 mg daily. For neuropathy: 1500-3000 mg daily. Take in the morning — may be mildly stimulating.Standard: 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.
AdministrationOral (capsules, powder). Well-absorbed on an empty stomach.Oral (oil, softgels, capsules). Cold-pressed oil preferred. Take with food.
Research Papers9 papers9 papers
Categories

Mechanism of Action

ALCAR

ALCAR crosses the blood-brain barrier via the organic cation transporter (OCTN2) more effectively than L-carnitine. In neurons, it is hydrolyzed by carnitine acetyltransferase to donate its acetyl group to coenzyme A, forming acetyl-CoA—which can then be used for acetylcholine synthesis via choline acetyltransferase, effectively providing raw material for the memory neurotransmitter. ALCAR also transports long-chain fatty acids across the inner mitochondrial membrane via the carnitine palmitoyltransferase system for beta-oxidation and ATP production. ALCAR activates nerve growth factor (NGF) signaling, possibly through modulation of NGF receptor (TrkA) expression or downstream MAPK/ERK pathways. It has antioxidant properties, reducing lipid peroxidation in mitochondrial membranes and scavenging free radicals. These mechanisms support cognitive function and neuroprotection.

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.

Risks & Safety

ALCAR

Common

Nausea, fishy body odor, restlessness, gastrointestinal discomfort.

Serious

May increase agitation in Alzheimer's patients. TMAO production may be a cardiovascular concern with chronic high doses.

Rare

Seizures in susceptible individuals, increased thyroid activity.

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.

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