What it is
L-arginine is an amino acid found in protein foods and made in the body. It is called conditionally essential: normally the body makes enough, but under stress or illness it may not.
What it does in Memoclear
Arginine is the direct raw material for nitric oxide. An enzyme in the lining of blood vessels converts it, and the nitric oxide produced tells the muscle around the vessel to relax. A relaxed vessel is a wider one, so more blood, oxygen and glucose reach the tissue it feeds. In Memoclear the base form is there to start that process soon after the capsule dissolves.
Where it comes from in food
Chicken, turkey, pork loin, pumpkin seeds, peanuts, soybeans and dairy.
What the research says
The arginine-to-nitric-oxide step is settled biochemistry. What is less tidy is delivery: a large share of swallowed arginine is broken down in the gut wall and liver, which is the so-called arginine paradox and the reason citrulline sits beside it on the label. Trials of arginine on blood-vessel function show modest effects; trials on memory in healthy adults are few.
Who should be careful
Arginine relaxes blood vessels. If you take blood-pressure medicine, nitrates or erectile dysfunction medicine, ask your doctor first. Anyone who has had a recent heart attack should not take arginine supplements without medical advice. It can trigger cold sores in people prone to them.
Where it sits in the Memoclear formula
L-Arginine (base) works alongside L-Arginine AKG 2:1 Extract, L-Citrulline HCl, L-Citrulline Malate, Beta-Alanine, Niacin (Vitamin B3), Calcium (as calcium carbonate). Together the seven cover nitric oxide, cell energy and nerve signalling in one daily capsule.
Further reading
The L-arginine paradox, Pharmacology & Therapeutics 2007. This research is on the ingredient, not on the finished Memoclear product.