Key takeaways
- Both amino acids help the body make nitric oxide.
- L-Citrulline is absorbed well and raises arginine levels more steadily.
- Using both gives quick and sustained support, which is why Alpha Erec pairs them.
What they have in common
L-Arginine and L-Citrulline are amino acids that feed the body's nitric oxide pathway. Nitric oxide signals blood vessel walls to relax, which lets more blood flow through. For the full picture, read nitric oxide and male performance.
L-Arginine: the direct building block
L-Arginine is the direct raw material for nitric oxide. The catch is that a large share of oral L-Arginine is broken down in the gut and liver before it reaches the bloodstream, so its effect can be short-lived on its own.
L-Citrulline: the steady supplier
L-Citrulline, found naturally in watermelon, skips much of that breakdown. The kidneys convert it into L-Arginine, which tends to raise arginine levels in the blood more steadily and for longer.
Why use both?
Combining them gives the body arginine right away and a steady supply over time. That is the thinking behind Alpha Erec's blend, which pairs both amino acids with Panax Ginseng, another ingredient studied for nitric oxide activity. See all nine in our ingredients guide.
Safety note
Because both amino acids affect blood vessels, they can add to the effect of nitrates, blood-pressure drugs and ED medication. Check with a doctor first, as explained in our Alpha Erec safety guide.
Frequently asked questions
Which is better, L-Arginine or L-Citrulline?
L-Citrulline raises arginine levels more steadily, while L-Arginine acts more directly. Many formulas use both to get the benefits of each.
What foods contain L-Citrulline?
Watermelon is the best-known source. Cucumbers, pumpkin and other melons contain smaller amounts.
This article is for general information only and is not medical advice. Talk to your doctor before starting any supplement. We may earn a commission from purchases made through our links; see our disclosure.
