L-Citrulline and the Brain: What We Know About Blood Flow and Memory
The citrulline loop
Citrulline is made in the gut and kidneys and recycled into arginine. Because it bypasses early breakdown, supplements can raise blood arginine effectively. A review compared arginine and citrulline effects on blood pressure, noting differences by dose and group.
From nitric oxide to neurons
Nitric oxide helps match blood supply to activity in the brain; see the neurovascular coupling study. Whether extra citrulline changes that in healthy adults is not shown.
What human studies measure
Most citrulline trials track exercise, fatigue and blood pressure rather than memory tests; see citrulline and exercise performance. HoneyPezil's use of two forms (HCl and malate) is a formulation choice; read citrulline malate benefits.
Safety
Citrulline is usually well tolerated, but large doses may cause stomach upset. Because it can lower blood pressure, check with a clinician if you take antihypertensives or nitrates; see the checklist.
Practical reading
If you hope citrulline will sharpen memory, set a measurable goal and track it. If you want a general brain-health plan, begin with sleep and walking; see walking for brain health.
Frequently asked questions
Sources
- PubMed: The effects of oral L-arginine and L-citrulline supplementation on blood pressure (2019)
- PubMed: Nitric oxide is fundamental to neurovascular coupling in humans (2020)
- PubMed: Effects of citrulline supplementation on exercise performance in humans (2020)
General information, not medical advice. Offer details were checked on November 11, 2026; confirm on the order page and read the label on your bottle. See our disclaimer and how we research.