Back to all supplements

Citrulline

30-60 minutes before exercise

Citrulline is a non-essential amino acid abundant in watermelon and naturally synthesized in the body through the urea cycle. It efficiently raises blood levels of L-arginine, making it a popular supplement for cardiovascular support, exercise performance, and blood flow enhancement.

Research Evidence
Reduces exercise-induced fatigue and improves endurance
Moderate
Supports healthy blood pressure in pre-hypertensive adults
Moderate
May improve erectile function through enhanced nitric oxide production
Moderate
Increases plasma arginine levels more effectively than arginine supplementation
Strong
Enhances post-exercise muscle recovery and reduces soreness
Limited
Source: Examine.com

Expert Evidence

7 references from 2 experts

“L-citrulline acts as sort of a donor or it's kind of a biological prerequisite for arginine and can lead to even bigger arginine increases than you would get if you took arginine itself.”

How to Control Your Metabolism by Thyroid & Growth Hormone

1:20:21

5 references in 4 episodes from 2021–2023

2023
2021
Safety & Cautions

Side Effects

  • Mild gastrointestinal discomfort at high doses
  • Possible nausea
  • Bloating or stomach cramps in sensitive individuals
Citrulline is generally well-tolerated with a strong safety profile at standard doses. Those taking blood pressure medications or nitrates should consult a healthcare provider, as citrulline may amplify vasodilatory effects.
Pairs Well With
GlutathioneTaurineGarlic Extract