Quick Comparison
| ALCAR | Omega-3 (DHA) | |
|---|---|---|
| Half-Life | 4-5 hours | 20-67 hours (plasma), but brain DHA turns over slowly over weeks |
| Typical Dosage | Standard: 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: 1-2 g combined EPA/DHA daily (aim for at least 500 mg DHA). For depression: 1-2 g EPA-dominant fish oil. Triglyceride form is better absorbed than ethyl ester. Take with a fatty meal. |
| Administration | Oral (capsules, powder). Well-absorbed on an empty stomach. | Oral (softgels, liquid). Triglyceride or phospholipid forms preferred over ethyl ester for bioavailability. Take with food containing fat. |
| Research Papers | 9 papers | 10 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.
Omega-3 (DHA)
DHA is a structural component of neuronal phospholipids (particularly phosphatidylethanolamine and phosphatidylserine in synaptic membranes), maintaining membrane fluidity which is essential for G-protein-coupled receptor function, ion channel gating, and synaptic vesicle fusion. DHA is metabolized by 15-lipoxygenase to specialized pro-resolving mediators (SPMs) including neuroprotectin D1 (NPD1), which actively resolve neuroinflammation by reducing NF-kappaB activation and pro-inflammatory cytokine production. DHA supports BDNF expression through modulation of the CREB pathway and promotes synaptic plasticity by enhancing long-term potentiation (LTP) and dendritic spine density. It also influences neurotransmitter receptor conformation and binding efficiency. Deficiency impairs membrane signaling, increases neuroinflammation, and accelerates cognitive decline.
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.
Omega-3 (DHA)
Common
Fishy aftertaste, burping, mild gastrointestinal discomfort.
Serious
High doses (>3 g/day) may increase bleeding risk — caution with blood thinners. Fish oil quality matters — choose products tested for mercury and oxidation.
Rare
Allergic reaction in people with fish/shellfish allergy.
Full Profiles
ALCAR →
Acetyl-L-Carnitine is an acetylated form of L-Carnitine that crosses the blood-brain barrier more effectively than regular L-Carnitine. In the brain, it donates its acetyl group for acetylcholine synthesis and supports mitochondrial fatty acid oxidation for energy. Used clinically for age-related cognitive decline, depression, and diabetic neuropathy.
Omega-3 (DHA) →
DHA (docosahexaenoic acid) makes up approximately 40% of the polyunsaturated fatty acids in the brain and is essential for neuronal membrane structure, fluidity, and signaling. DHA deficiency is associated with cognitive decline, depression, and neuroinflammation. It is one of the few supplements with strong evidence for maintaining brain health across the lifespan.