How Does Memodyne Work? Arginine, Citrulline and Blood Flow
Quick answerMemodyne is built on a blood-flow idea.
The body uses arginine to make nitric oxide, which relaxes blood vessels, and it turns citrulline into arginine. The label calls the mix a Cognitive Support Formula because the brain relies on good blood flow.
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What is the idea behind Memodyne?
The idea is blood flow. Memodyne combines two amino acids, arginine and citrulline, that feed the body's nitric oxide system. Nitric oxide helps blood vessels relax and widen.
The brain is a heavy user of blood. It is a small organ, but it uses a large share of the oxygen the body takes in. So the brand links a blood-flow formula to thinking, and the label calls it a Cognitive Support Formula.
The graphic beside this text is the brand's own. The rest of this page explains each step in plain words, and then what research has and has not shown.
How does arginine become nitric oxide?
The inner lining of every blood vessel holds an enzyme called nitric oxide synthase. It takes arginine and turns it into nitric oxide plus citrulline. The nitric oxide drifts into the muscle layer of the vessel wall.
There it signals the muscle to relax. The vessel widens, and blood moves through with less push. Nitric oxide lasts only seconds, so the body makes it all the time.
Why add citrulline as well as arginine?
Arginine taken by mouth has a problem. A good share is broken down in the gut and liver before it reaches the rest of the body. Citrulline mostly slips past that step. The kidneys then turn it into arginine.
In healthy volunteers, oral citrulline raised blood arginine more efficiently than the same amount of arginine (Schwedhelm et al., 2008). That is why many formulas pair the two. It also explains the loop in the pathway: making nitric oxide leaves citrulline behind, which can be turned back into arginine.
Two forms of each. Memodyne lists arginine as a plain base form and as an AKG salt, 200 mg each. It lists citrulline as an HCl salt and as a malate salt, 100 mg each.
Part of each salt's weight is the carrier, not the amino acid. Details are on the L-arginine and L-citrulline pages.
What do the other three lines do?
The remaining lines do not feed nitric oxide. They have their own, simpler jobs.
| Label line | Amount | What it does in the body | How much that is |
|---|---|---|---|
| Beta Alanine | 40 mg | Builds carnosine, an acid buffer in muscle | About 1% of a 4 g sports dose (Trexler et al., ISSN 2015) |
| Niacin | 7.5 mg NE | Helps cells turn food into energy | About half a day's need (NIH ODS, Niacin) |
| Calcium | 18 mg | Bones, nerves and muscle signals | Under 2% of a day's need (NIH ODS, Calcium) |
| L-Arginine, two forms | 400 mg | Raw material for nitric oxide | About 12% of a small memory trial's daily dose (Mone et al., 2022) |
| L-Citrulline, two forms | 200 mg | Turned into arginine | A small fraction of trial doses (Khalaf et al., 2019) |
How does blood flow connect to memory?
Nerve cells need a steady supply of oxygen and sugar, and blood brings both. Long-term damage to small blood vessels in the brain is linked to thinking problems as people age.
This is one reason doctors stress blood pressure control for brain health. Nitric oxide also acts as a messenger between some nerve cells, which makes it an active research topic.
A link in biology is not proof that a pill helps. Plenty of things matter to the brain without a supplement changing them.
What is known and what is not?
Some steps in this story are solid. Others are guesses that have not been tested. The table sorts them.
| Statement | Status | Source |
|---|---|---|
| The body makes nitric oxide from arginine | Known | (Schwedhelm et al., 2008) |
| Oral citrulline raises blood arginine | Shown in healthy volunteers | (Schwedhelm et al., 2008) |
| Arginine at 4 to 24 g a day lowers blood pressure a little | Shown in a review of 11 trials | (Dong et al., 2011) |
| Arginine and citrulline at gram doses change blood pressure | Results vary | (Khalaf et al., 2019) |
| Arginine changed thinking scores in frail older adults with high blood pressure | One small, short, single-blind trial at 3.3 g a day | (Mone et al., 2022) |
| These amino acids help memory in healthy people | Not shown | No review found that shows it |
| Memodyne at 400 mg arginine a day helps memory | Not studied | No study published |
Honest note: the gap between the idea and the capsule
No study of Memodyne has been published. The one arginine memory trial we found used 3.3 g a day for four weeks, in 72 frail older adults with high blood pressure (Mone et al., 2022). Memodyne lists 400 mg of arginine across two forms, about 12% of that dose. The blood pressure trials used 4 to 24 g.
US health agencies say direct evidence that supplements prevent dementia is lacking (NCCIH, Supplements for cognitive function). So the fair way to describe Memodyne is a small-dose nitric oxide formula sold for cognitive support, not a tested memory product.
L-ArginineAbout 12%
Beta AlanineAbout 1%
Memory evidenceNo product study
No study of Memodyne has been published. The one arginine memory trial we found was small, short and used about 8 times more arginine. (Mone et al., 2022)
Who should check with a doctor before trying it?
Because the formula targets blood vessels, the main cautions are about blood pressure and the heart.
Ask first if this is you
- People on blood pressure medicine: arginine and citrulline may add to it (Mayo Clinic, L-arginine)
- Anyone using nitrates such as nitroglycerin, or ED pills like sildenafil (Mayo Clinic, L-arginine) (WebMD, L-citrulline)
- Anyone who has had a heart attack: an arginine trial found no benefit and more deaths (Schulman et al., JAMA 2006)
- Pregnant or nursing women and anyone under 18, as the label says
- Anyone with a known medical condition, as the label says
New memory trouble that disrupts daily life needs a doctor, not a supplement (NIA, Memory problems and aging). Sudden confusion, trouble speaking or numbness on one side can be a stroke: call 911 and note the time (CDC, Stroke signs). Our side effects page has the full safety picture.
How should you take Memodyne if you decide to try it?
The label says one capsule a day with an 8 oz glass of water, 20 to 30 minutes before a meal. The label does not explain the timing, and no study tested it. Do not take more than one. Our how to use guide covers timing and what to track.
How it works FAQ: questions about Memodyne
How does Memodyne work?
It is based on the nitric oxide pathway. Arginine is used to make nitric oxide, which relaxes blood vessels, and citrulline is turned into arginine. No study has tested the capsule itself.
What does nitric oxide do for the brain?
Nitric oxide helps blood vessels widen, including those that feed the brain. It also works as a signal between some nerve cells. Neither fact shows that a supplement helps memory.
Does L-arginine increase blood flow to the brain?
Arginine is the raw material for nitric oxide, which widens vessels. Whether a 400 mg oral dose changes brain blood flow in healthy people has not been shown.
Why is Memodyne called a Cognitive Support Formula?
That is the brand's label wording. The asterisk points to the FDA statement that these words were not evaluated by the FDA.
Is L-citrulline better than L-arginine?
Taken by mouth, citrulline raised blood arginine more efficiently than the same amount of arginine in one study. That is why many formulas use both.
How long does it take for Memodyne to work?
No one can say. There is no trial of the product, so there is no tested timeline for any change.
Is Memodyne a nitric oxide supplement?
Its main amino acids are the same ones sold in nitric oxide and workout formulas. The label sells the mix for cognitive support instead.
Can nitric oxide supplements lower blood pressure?
At gram doses, arginine lowered blood pressure a little in trials. That is why people on blood pressure drugs, nitrates or ED pills should ask a doctor first.
Does Memodyne have any clinical studies?
No study of Memodyne has been published. One small arginine trial in frail older adults used about eight times more arginine per day.
Ready to try Memodyne?
One capsule a day, 30 per bottle, from $49 a bottle on the 6-bottle pack, with a 60-day money-back window shown on the sales page. Take blood pressure or heart medicine? Ask your doctor first.
