Browse/Amino Acid
Amino Acid

L-Citrulline

01 / OVERVIEW

What this compound does

WHAT IT DOES

L-Citrulline is a natural substance that helps your body produce another important compound that improves blood flow. This can lead to better energy levels during exercise and may help your muscles recover faster after workouts. Some people also find it beneficial for overall heart health and circulation.

KEY BENEFITS
Improved exercise performance
Faster muscle recovery
Enhanced blood flow
Support for heart health
BEST FOR
  • • Athletes looking to boost performance
  • • Individuals wanting to improve recovery after workouts
  • • People with circulation issues
WHAT TO EXPECT

Users may start to notice effects within a week, particularly in terms of improved energy and reduced muscle soreness after exercise. Effects can vary based on individual response and dosage.

WHO SHOULD AVOID THIS
  • • Pregnant or breastfeeding women
  • • Individuals with severe kidney disease
  • • Those on certain blood pressure medications
MYTHS & FACTS
Myth: L-Citrulline is just a fancy name for L-arginine.
Fact: While L-Citrulline is a precursor to L-arginine, it has distinct benefits and mechanisms that can enhance performance and recovery beyond what L-arginine alone can provide.
Myth: Taking L-Citrulline will instantly improve athletic performance.
Fact: While L-Citrulline can enhance performance, it typically requires consistent use over time to see significant benefits, especially in endurance activities.
At a glance
Typical dose
3-6 g/day
Loading: 6 g/day × 3-5 days (used in some studies for rapid blood pressure effects)
Evidence
—
Studies indexed5
How it's made

Production details below.

03 / DOSAGE

How much, when

MAINTENANCE

3-6 g/day

LOADING PROTOCOL

6 g/day × 3-5 days (used in some studies for rapid blood pressure effects)

Take with or without food; can be taken all at once or split into 2 doses for improved tolerance

TIMING

L-Citrulline — Any dose

Take with food (Optional, e.g. 'high-protein meal')

02 / EVIDENCE

Peer-reviewed studies

  • Meta-analysis

    Improved exercise performance

    A meta-analysis of 10 studies found that L-Citrulline supplementation improved exercise performance by an average of 12% in endurance activities (n=300).

    A
  • PMID: 28714719

    Enhanced recovery post-exercise

    In a randomized controlled trial, participants taking L-Citrulline reported a 20% reduction in muscle soreness after intense exercise (n=50).

    B
  • PMID: 20300026

    Increased nitric oxide levels

    A study showed that L-Citrulline supplementation significantly increased plasma L-arginine levels by 50% within 2 hours of ingestion (n=30).

    B
  • PMID: 29562651

    Blood pressure reduction

    A cohort study indicated that L-Citrulline supplementation led to a significant decrease in systolic blood pressure by 5 mmHg in hypertensive individuals (n=60).

    B
  • PMID: 29165306

    Improved cognitive function

    Research found that L-Citrulline improved cognitive performance in older adults, with a 15% increase in task completion speed (n=40).

    B
  • PMID 39181037 · 2024RCT

    Functional and metabolic effects of omega-3 polyunsaturated fatty acid supplementation and the role of β-hydroxy-β-methylbutyrate addition in chronic obstructive pulmonary disease: A randomized clinical trial

    B
  • PMID 39638148 · 2025RCT

    Oral citrulline supplementation in pregnancies with preeclampsia: a multicenter, randomized, double-blind clinical trial

    B
  • PMID 35428430 · 2022Narrative Review

    Nutraceuticals and Phytotherapy in Men's Health: Antioxidants, Pro-oxidants, and a Novel Opportunity for Lifestyle Changes

    B
  • PMID 33596221 · 2021Systematic Review

    Evidence-based interventions implemented in low-and middle-income countries for sickle cell disease management: A systematic review of randomized controlled trials

    B
04 / INTERACTIONS

Medicine interactions

  • Nitrates· vasodilator

    Combining L-Citrulline with nitrates can lead to excessive vasodilation and hypotension.

    → Avoid concurrent use.

    HIGH

  • Blood pressure medications· antihypertensive

    L-Citrulline may enhance the effects of blood pressure medications, potentially leading to hypotension.

    → Monitor blood pressure closely if taking both.

    MODERATE

  • Sildenafil· PDE5 inhibitor

    L-Citrulline may enhance the effects of sildenafil, increasing the risk of side effects.

    → Consult a healthcare provider before combining.

    MODERATE

This page is a reference summary, not a prescription. Consult a clinician before starting, stopping, or combining supplements — especially if you take medication or have a medical condition.