Citrulline
Citrulline is a non-essential amino acid naturally produced in the body and found in certain foods like watermelon. It plays a role in the urea cycle, helping to remove ammonia from the blood, and is converted in the kidneys to L-arginine, which is involved in nitric oxide production. This supplement is used by individuals seeking to support cardiovascular health, exercise performance, and blood flow, as well as in certain clinical settings.
Citrulline is an amino acid supplement that supports blood flow and exercise performance by boosting nitric oxide production.
Key facts at a glance
- ATC
- unclassified
- RxNorm
- unknown
- Generic
- Citrulline
- Class
- unclassified
- Brands
- —
- Availability
- otc
- Pregnancy
- N
- Lactation
- safe
- Half-life (h)
- 1
- Onset (min)
- 30
- Duration (h)
- 4
- Routes
- oral
- Forms
- capsules, tablets, powders
- Regions
- United States, Canada, United Kingdom, Germany, Japan, Australia
- Monitoring
- blood pressure
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Used to support cardiovascular health, improve blood flow, enhance athletic performance, support blood pressure within normal range, and may be used as a dietary supplement for general wellness. Sometimes used in clinical settings for conditions affecting circulation.
Citrulline is converted to L-arginine in the kidneys, which then serves as a precursor to nitric oxide—a molecule that helps dilate blood vessels and improve circulation. It also supports the urea cycle, aiding in the removal of metabolic waste products.
Generally well-tolerated when used at recommended doses. May interact with blood pressure medications, erectile dysfunction drugs, or nitrates. Consult a healthcare provider before use if pregnant, nursing, taking medications, or having any medical conditions.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 27, 2026. · Read our editorial policy