Quick answer
L-citrulline and L-arginine are closely related amino acids. The body can convert citrulline into arginine. Citrulline was named after watermelon (Citrullus), where it was first found, while arginine is found in protein foods such as meat, nuts and seeds.
Citrulline named after
Watermelon, Citrullus lanatus
Relationship
The body converts citrulline into arginine
Arginine in food
Meat, fish, nuts, seeds, legumes
MAYN product
L-Citrulline 750mg, 90 capsules
What is L-citrulline?
L-citrulline is an amino acid that isn't used to build proteins. It was first identified in watermelon in the early 20th century, and the name comes from the watermelon's Latin name. Watermelon (especially the rind) remains its best-known food source.
What is L-arginine?
L-arginine is one of the amino acids used to build proteins. It's found in many protein foods, including meat, poultry, fish, dairy, nuts, seeds and legumes.
Citrulline vs arginine at a glance
| L-citrulline | L-arginine | |
|---|---|---|
| Used to build proteins? | No | Yes |
| Best-known food source | Watermelon | Meat, nuts, seeds |
| Relationship | Converted to arginine in the body | Made partly from citrulline |
| Common label amounts | 750mg–3g | 500mg–3g |
Citrulline is part of the urea cycle, a natural process in which citrulline and arginine are converted into each other.
How to choose a citrulline supplement
- Check whether it's L-citrulline or citrulline malate (a blend with malic acid).
- Compare the milligrams per serve.
- Follow the label directions for how many capsules make a serve.
Frequently asked questions
Is citrulline the same as citrulline malate?
No. Citrulline malate combines citrulline with malic acid, so a gram of citrulline malate contains less citrulline than a gram of pure L-citrulline.
How much citrulline is in watermelon?
It varies by variety and ripeness, and the rind contains more than the flesh.
Is L-citrulline an essential amino acid?
No. The body can make citrulline.
Keep reading
This article is general information only and is not medical advice. Always read the label and follow the directions for use. Dietary supplements should not replace a balanced diet. If you are pregnant, breastfeeding, taking medication or have a medical condition, speak with your doctor or pharmacist before taking a new supplement.
