MemoHoney Ingredients: seven amounts, and what each was tested at

The starting material. Nitric oxide synthase takes arginine and produces nitric oxide, the short-lived gas that tells the smooth muscle around a blood vessel to relax. That much is settled biochemistry and it is the reason arginine appears in a formula sold for blood flow.

Swallowing it is the difficulty. A stable-isotope study followed labelled dietary arginine through healthy adults and found most of it consumed by urea synthesis and gut metabolism before it could reach the systemic circulation (a stable-isotope study of dietary arginine). The practical answer the field settled on was not more arginine but a different molecule, which is why two citrulline forms sit on this same label.

A 2019 review of oral arginine and citrulline in blood pressure is the nearest thing to a clinical summary (a 2019 review of oral arginine and citrulline), and it deals with blood pressure rather than with recall. The panel lists 200 mg of arginine base.

Two parts arginine bound to one part alpha-ketoglutarate. The commercial argument is that the salt survives digestion better than free arginine; the published record is a pre-workout record rather than a cognitive one.

The pharmacokinetic trial that is usually cited for it gave 4 g three times a day, 12 g in total, and measured what appeared in plasma (the arginine AKG pharmacokinetic trial). A separate trial gave 3,000 mg before a single training session and reported nothing measurable (an acute arginine AKG trial). A third gave 12 g a day for a week and looked at blood flow (a seven-day arginine AKG trial).

Twelve grams is the figure to keep in mind while reading the rest of this page, and the panel's 200 mg is one sixtieth of it. That is not an argument that the ingredient does nothing. It is the scale at which somebody went looking.

Citrulline is the answer the field found to the arginine problem. It passes the gut and the liver largely intact and is converted to arginine in the kidney, so a gram of citrulline raises plasma arginine more reliably than a gram of arginine does (a human citrulline availability study). A 2026 rat pharmacokinetic study characterises the same conversion in detail (a 2026 rat pharmacokinetic model).

The one trial that measured blood flow to the brain gave 8.8 g a day for five days to athletes doing sprint interval training, and reported changes in cerebral oxygenation during the work (the citrulline cerebrovascular trial). That is the closest the citrulline literature comes to this product's use case, and it is still a long way from a person at a desk taking the 100 mg this panel lists.

A separate trial in older adults used citrulline alongside exercise (a review of citrulline in older adults), and a 2025 meta-analysis covers the blood pressure question (a 2025 meta-analysis of citrulline and blood pressure).

The same citrulline joined to malic acid, and the form most of the sports literature actually uses. A 2024 and a 2026 trial define its current evidence: three days of 8 g a day improved repeated sprint running in male team-sport athletes (a three-day citrulline malate trial), and a dose-comparison pilot set 8 g against 12 g acutely in resistance exercise (a moderate-versus-high-dose citrulline malate trial).

An older-adult trial used 3 g a day for six weeks alongside training (a citrulline malate trial in older women), which is the smallest amount anywhere in this ingredient's record and still thirty times the 100 mg on this panel.

Nothing in that set measured memory, recall or attention. It measured sprints, lifts and function in the legs.

The one ingredient on this label at a nutritional amount: 7.5 mg NE, 47% of the Daily Value. Niacin becomes NAD and NADP, the two coenzymes that move electrons through energy metabolism, and severe deficiency causes pellagra, whose three classical symptoms end in dementia.

That last fact is where the cognitive argument comes from, and it needs handling carefully: correcting a deficiency is not the same as improving a brain that is not deficient. The observational evidence is a large dietary cohort in which higher niacin intake tracked with lower Alzheimer risk (the Chicago Health and Aging Project analysis), and an observational cohort is not a trial.

The amounts are worth knowing in both directions. The US tolerable upper intake level is 35 mg a day (the 2017 niacin upper-intake review); high-dose niacin as a cardiovascular drug was tested at gram scale and the large trial of it was stopped for harm rather than benefit (the HPS2-THRIVE trial), which is a different substance at a different dose and a good reason not to add over-the-counter niacin on top of a capsule (a survey of over-the-counter niacin products).

Carnosine is a dipeptide that buffers acid inside muscle, and beta-alanine is the half of it the body runs short of. Carnosine is also present in brain tissue, which is the thread this ingredient hangs on.

The interesting study is small and genuinely about the brain: 2.4 g a day in adults aged 60 to 80, with imaging of the hippocampus as the outcome (the beta-alanine brain-imaging trial). Against that sits the sports meta-analysis, where 3.2 to 6.4 g a day produced a pooled effect size of 0.18 (the 2017 beta-alanine meta-analysis), and a safety review of chronic supplementation (the beta-alanine risk assessment). A military cognitive trial used it under stress (an evidence review for military use), and a trial of carnosine itself in older adults used 2 g a day (the NEAT carnosine trial).

The tingling people report on beta-alanine, paraesthesia, is harmless and dose-related. At the 40 mg this panel lists it is very unlikely, and its absence is not evidence of anything.

The seventh line, and the one the seller's advertising never mentions. Calcium carbonate is one of the usual forms of calcium in supplements, and at 18 mg it is one and a half percent of the Daily Value: a trace, not a dose of anything.

It earns a card for one reason. Somebody adding up calcium across several products, or told to keep calcium away from a particular medicine, is entitled to know it is in the capsule, and only the panel says so.