L-Citrulline Malate
Boosts nitric oxide for better pumps, endurance, and blood flow.
- Typical dose
- 6–8 g
- When to take
- Afternoon
- Onset
- 30–90 minutes after a dose; noticeable in the first workout
What it does
Benefits
- Increases nitric oxide and blood flow
- Reduces muscle fatigue during training
- Improves endurance on high-rep sets
- May reduce post-workout soreness
The science
How it works
L-citrulline converts to L-arginine in the kidneys more efficiently than oral arginine itself, raising plasma arginine and nitric oxide — which dilates blood vessels and improves substrate delivery to working muscle.
Getting it right
Dose & timing
Dose guidance
6–8 g citrulline malate (or 3–5 g pure L-citrulline) 30–60 min pre-workout. Higher doses don't add much.
Best time to take
Pre-workout, on an empty stomach or with a light snack.
Is it for you?
Who should (and shouldn't) take it
Good for
- Lifters chasing better pumps
- Endurance athletes
- CrossFit and HIIT
- Anyone plateauing on volume
Skip or ask a doctor if
- You have low blood pressure
- You take ED medications or nitrates
- You have kidney disease
Know before you start
Side effects & safety
- Mild GI discomfort at high doses
- Lightheadedness if combined with other vasodilators
Shopping guide
Forms & what to look for
- Citrulline malate 2:1
Most researched form; malate adds ATP support
- Pure L-citrulline
Slightly higher citrulline per gram; less GI
- Powder
Best — mix into pre-workout drink
Combining
Stacks well with / avoid pairing
Stacks well with
Common questions
FAQ
How is this different from arginine?
Citrulline raises arginine levels in your body more reliably — oral arginine is broken down in the gut.
Pre-workout or daily?
Pre-workout is where it shines. Daily is unnecessary.
References
Sources & further reading
Educational only, not medical advice. Check with a clinician before starting anything new, especially if you're on medication or pregnant.