Citrulline
Citrulline boosts nitric oxide production, leading to better blood flow and more pump during your workout. It also improves endurance.
Clinical dosage
Origin
Natural & syntheticNamed after watermelon (Citrullus lanatus), where it naturally occurs. Also found in cucumber and pumpkin. In supplements usually synthetically produced as L-citrulline or citrulline malate.
Safety
Citrulline has an excellent safety profile. Doses up to 10g per day are well tolerated without significant side effects. Your body also produces it naturally as an intermediate in the urea cycle.
For comparison
To get 3g of citrulline from watermelon, you'd need to eat over 3 pounds of watermelon. That's why supplements are much more practical for sports dosages.
Dosage by weight and gender
The effective citrulline dose for sports performance is 6-8g L-citrulline or 8-10g citrulline malate per session (Gonzalez & Trexler, 2020). Body weight plays a limited role since the effect is local in blood vessels. There are no meaningful differences between men and women. With citrulline malate, about 55% is actual citrulline, so you need a higher dose than pure L-citrulline.
Frequently asked questions
What is citrulline?▼
Citrulline is an amino acid your body converts to arginine, which boosts nitric oxide (NO) production. This widens your blood vessels so more blood and oxygen reach your muscles.
Is citrulline dangerous?▼
No. Citrulline is one of the safest pre-workout ingredients. Doses up to 10g per day are well tolerated without notable side effects.
How much citrulline should I take per day?▼
Take 6-8g L-citrulline or 8-10g citrulline malate about 30-40 minutes before training. Many pre-workouts only contain 3g, which is really too little for a noticeable effect.
Scientific sources
The clinical dosages on this page are based on peer-reviewed research.
- Citrulline malate enhances athletic anaerobic performance and relieves muscle sorenessPerez-Guisado J, Jakeman PM — J Strength Cond Res (2010)
- L-citrulline supplementation: Impact on cardiometabolic healthAllerton TD et al. — Nutrients (2018)
Pre-workouts with Citrulline
Cellucor C4 Ultimate
Premium C4 with 300mg caffeine, 6g citrulline malate, 3.2g beta-alanine, and 3g creatine. Fully clinically dosed — top of the C4 line.
BSN N.O.-Xplode
Legendary pre-workout from BSN with 6g citrulline, 3g creatine, and 200mg caffeine. Popular for years with a complete formula for energy and pump.
5% Nutrition 5150
Hardcore pre-workout with 400mg caffeine from multiple sources, 4g citrulline, and 2.5g beta-alanine. Not for beginners — one of the strongest pre-workouts on the market.
5% Nutrition Kill It
Pre-workout from Rich Piana's 5% Nutrition with creatine, citrulline, and caffeine. Broad spectrum but lower individual dosages.
JNX Sports Shadow-X
Thermogenic pre-workout from JNX Sports with 200mg caffeine, 2g citrulline, and 2g beta-alanine. Focus on energy and concentration.
JNX Sports The Curse!
Compact pre-workout with small serving size (5g). 155mg caffeine, 1.6g beta-alanine, and creatine. Known for intense focus but low dosages.