L-Citrulline — Blood Flow & Pump Support
L-Citrulline — Blood Flow & Pump Support
What is L-citrulline and how does it improve training performance?
L-citrulline is an amino acid that the body converts into L-arginine and then into nitric oxide (NO) — a molecule that dilates blood vessels and improves blood flow to muscles. This process increases oxygen and nutrient delivery during training, leading to better endurance and muscle pump effects. Citrulline is more effective than arginine at raising NO levels because it is not broken down during first-pass liver metabolism, making it one of the most popular pre-workout supplements among strength and endurance athletes.
Frequently asked questions about L-citrulline
L-citrulline is the pure amino acid, while citrulline malate is a combination of citrulline and malic acid (malate) in a 2:1 ratio. The malate component supports energy production in the Krebs cycle. Citrulline malate is often recommended for training performance, but pure citrulline provides a stronger NO-boosting effect gram for gram.
For pure L-citrulline, 3-6 grams is recommended 30-60 minutes before training. For citrulline malate, the effective dose is 6-8 grams (containing about 4-5 grams of pure citrulline). For best results, take citrulline consistently every day, not only on training days.
Yes, citrulline pairs excellently with other pre-workout supplements. Popular combinations include citrulline + beta-alanine for endurance, citrulline + caffeine for energy, and citrulline + creatine for strength. Many pre-workout products already contain citrulline, so check ingredients to avoid double-dosing.
L-citrulline is generally very well tolerated. Rare side effects may include mild stomach discomfort or digestive upset, especially with larger doses on an empty stomach. Those taking blood pressure medications should consult their doctor, as citrulline may slightly lower blood pressure. No other significant side effects have been found in research.