L-citrulline explained: what it is and side effects
According to the NIH, your body produces citrulline mainly from the amino acid glutamine, and citrulline takes part in the body's urea cycle and is used to make arginine. It can also come from food, including watermelon. One product we reviewed lists L-citrulline, and no labels print its individual amount.
- What it is
- Amino acid
- Amounts the NIH names
- Studies used up to 9 grams of citrulline for one day or 6 grams per day for up to 16 days.
- In the products we reviewed
- 1, its label does not print the amount
What L-citrulline is
- Citrulline is made in the body mainly from glutamine and can also come from food.2
- Your body produces citrulline mainly from the amino acid glutamine.1
- A cup of diced seedless watermelon contains about 365 mg of citrulline.2
- Citrulline takes part in the body's urea cycle and is used to make arginine.1
- Your kidneys convert most citrulline into another amino acid called arginine.3
- Your body converts the arginine made from citrulline into nitric oxide, which widens blood vessels.3
- Supplements provide citrulline either on its own or as citrulline malate.2
Foods that have it2
- Watermelon
How much L-citrulline each product gives
NIH: 9,000 mg per dose
Amount not printed: the dashed line shows the most it can be, the whole blend
Before you take it
The product we reviewed that lists L-citrulline
| Product | Form and serving | L-citrulline per serving | Our score | Price a bottle | Buy |
|---|---|---|---|---|---|
 BoostaroMen's health support | Capsules2 capsules | Not printedIn a 645 mg proprietary blend | Not ranked | $49 | Check price |
Questions people ask
What is L-citrulline?
Citrulline is an amino acid your body makes mainly from glutamine, according to the NIH. The NIH says citrulline takes part in the body's urea cycle and is used to make arginine.
What foods have L-citrulline?
Watermelon contains citrulline. According to the NIH, a cup of diced seedless watermelon contains about 365 mg.
How much L-citrulline should I take per day?
The NIH names study amounts of up to 9 grams of citrulline for one day or 6 grams per day for up to 16 days. These study amounts are not a personal dosing recommendation. Ask a clinician before starting.
What are the side effects of L-citrulline?
Citrulline can cause stomach discomfort. The safety of taking citrulline supplements for months at a time has not been adequately studied. Ask a clinician before starting.
How is L-citrulline connected to nitric oxide?
According to the NIH, your body converts the arginine made from citrulline into nitric oxide, which widens blood vessels. Your kidneys convert most citrulline into another amino acid called arginine.
Which products we reviewed contain L-citrulline?
Boostaro is the only product we reviewed that lists L-citrulline. Its serving is 2 capsules, with L-citrulline inside a 645 mg proprietary blend and no separate amount printed.
Sources
The products, amounts and prices come from each product's label and checkout, as its review shows them. AI drafts our pages from listed sources, figures are checked against them, and we have not tried the products.
- 1NIH Office of Dietary Supplements, PrimaryMitochondrialDisorders HealthProfessionalods.od.nih.gov/factsheetschecked
- 2NIH Office of Dietary Supplements, ExerciseAndAthleticPerformance HealthProfessionalods.od.nih.gov/factsheetschecked
- 3NIH Office of Dietary Supplements, ExerciseAndAthleticPerformance Consumerods.od.nih.gov/factsheetschecked