Memodyne Ingredients: the six names and what each one is

Niacin is a B vitamin with two supplement forms that behave very differently. Nicotinic acid opens skin capillaries and produces the flush that anyone who has taken a high-dose B complex will recognise. Nicotinamide does not flush and is used at higher amounts without it.

The number to hold is 35 mg a day, the US tolerable upper intake level for the supplemental nicotinic acid form. The meta-analysis that defined it pooled 47 studies covering 11,741 people and concluded that in healthy adults taking nicotinic acid alone, major adverse effects appeared below 1,000 mg a day, which is why its authors called the 35 mg limit conservative.

The frightening niacin headlines belong to a different product entirely. HPS2-THRIVE gave 2,000 mg a day of extended-release niacin with laropiprant to 25,673 patients and found excess new-onset diabetes, bleeding and infection. That is a lipid drug at roughly sixty times the upper intake level, not a vitamin in a capsule.

Niacin matters on this particular bottle for one reason: it is the only ingredient here whose meaningful amount is small enough to fit alongside five others. That makes the printed panel worth reading on arrival.

Calcium carbonate is chalk. It is the calcium in an antacid tablet and in most bone-density supplements, and it is an unusual thing to find on a cognitive label at all.

It is also the one name on this artwork that the seller's own sales page leaves out, printing beta-alanine in its place. This desk follows the artwork, because the artwork is what will be on the container in your kitchen.

The honest note about calcium and cognition points away from the product rather than towards it. A seven-year longitudinal analysis in ageing women found that reported calcium supplement use tracked roughly threefold higher odds of cognitive decline (odds ratio 3.64, 95% confidence interval 1.47 to 9.01), with decline occurring in 26 per cent of participants overall. That is an observational association in a specific population at bone-medicine amounts, it is not evidence of harm from a capsule whose calcium content is unstated, and it is not a reason to panic. It is a reason not to pretend calcium is here for its cognitive record, because it does not have a good one.

The practical point is simpler. Anyone already taking calcium for bone density is getting several hundred milligrams a day, and calcium binds certain thyroid and antibiotic medicines in the gut. Read the printed panel before adding a second source. The NIH Office of Dietary Supplements calcium fact sheet sets out the intake reference ranges.

Arginine is the raw material the body uses to make nitric oxide, the molecule that relaxes blood-vessel walls. On paper it is the obvious ingredient for any formula selling blood flow.

In practice, oral arginine has a problem that has been understood for two decades. The gut wall is rich in arginase, an enzyme that converts arginine to ornithine and urea before it ever reaches the bloodstream. A stable-isotope study in humans traced a labelled arginine meal and showed how much of it is routed to urea synthesis rather than to nitric oxide.

That first-pass loss is the whole reason citrulline appears on modern labels, and it is why a formula that names both is not simply doubling up. It is naming the substrate and naming the workaround.

A 2019 review of oral arginine and citrulline on blood pressure found measurable reductions in systolic and diastolic pressure from supplementation, which is the effect worth knowing about before stacking this with a blood-pressure medicine.

Arginine alpha-ketoglutarate pairs two arginine molecules with one of alpha-ketoglutarate, a Krebs-cycle intermediate. The 2:1 in the name is that ratio. It arrived through bodybuilding supplements in the 2000s on the theory that the AKG portion would spare arginine from breakdown.

The human evidence is thin and it is not about brains. The randomised trial on the PubMed record is a twelve-day study in forty adolescent track athletes that gave 10 g of arginine AKG a day alongside 7.5 g of a second ingredient and measured jump height. The supplement group did not lose countermovement jump height across a training block while the placebo group did.

Ten grams a day, in fifteen-year-old runners, measured on a jump mat. It is a real finding and it has nothing whatever to say about memory in a fifty-year-old, which is exactly why it is printed here rather than summarised as clinically studied.

This is the best-evidenced name on the bottle, and it is worth saying so plainly on a page that is otherwise cautious.

Citrulline is absorbed largely intact, bypasses the intestinal arginase that destroys oral arginine, and is converted to arginine in the kidney. A double-blind crossover trial in twenty healthy volunteers compared six dosing regimes of citrulline, arginine and placebo after a week of supplementation. Citrulline raised plasma arginine dose-dependently and more effectively than arginine did. At 3 g twice a day it lifted the arginine-to-ADMA ratio from 186 to 278 and raised urinary nitrate and cyclic GMP.

The same paper reports the limit honestly: no arm improved flow-mediated dilation over its own baseline, though across the pooled data the change in the arginine-to-ADMA ratio did correlate with the change in dilation.

Longer trials found more. A twelve-week randomised study of 3,000 mg a day in 66 adults around 63 improved flow-mediated dilation, but only in the participants whose blood pressure was high-normal at baseline, and a four-week trial of 6 g a day in adults around 62 improved dilation, arterial stiffness and fasting glucose.

Three grams a day is the low end of what worked. That is the figure to hold beside a single capsule shared with five other ingredients.

Citrulline malate is citrulline paired with malic acid, another Krebs-cycle intermediate. It is the form sports nutrition standardised on, and the bodybuilding literature around it is large.

Whether the malate adds anything has now been tested directly. A randomised double-blind crossover trial in trained young adults set a single dose of plain L-citrulline against the same dose of citrulline malate on neuromuscular performance, and a six-week parallel trial did the same over a training block with blood biomarkers attached. Neither found the malate form superior.

For a cognitive product that already names citrulline HCl, the malate is therefore best read as a second source of the same amino acid rather than as a sixth distinct active. A review of citrulline and exercise performance reaches the same place from the sports side.