Evidence B · Good
Water-soluble
Acute (15min–1h)
An arginine precursor more effective than arginine taken directly (it escapes the hepatic "first pass"). It raises NO in a sustained way. Nitrosigine® (arginine silicate + inositol) delivers an effect within 15 min and lasts up to 6h.
Citrulline Malate dose6–8 g, 30–60min pre
Nitrosigine dose1.5 g, 15min pre
TimingPre-workout
FoodIndependent
Notes
- The effect on strength/endurance is statistically significant but the effect size is small (Hedges' g ≈ 0.20).
- Nitrosigine + Citrulline malate have a comparable vasodilatory effect (+31% vs. +34% FMD).
- It can cause a slight drop in blood pressure — caution in people with low blood pressure.
- Why not pure Arginine: Arginine is largely degraded by the liver before reaching the bloodstream. Citrulline passes straight through and is converted in a sustained way.
Comparison: Citrulline Malate vs. Nitrosigine
| Feature | Citrulline Malate | Nitrosigine® |
|---|---|---|
| Onset of action | 30–60 min | 15 min |
| Duration | ~3–4h | up to 6h |
| Effective dose | 6–8g | 1.5g |
| Cost | $ (cheap) | $$$ (premium) |
| Extra mental focus | — | Yes (cognition) |