Citrulline

Also known as: L-citrulline, citrulline malate

Grade B — Moderate Evidenceamino acidperformance
3–8 g30-60 min before exercise (citrulline malate: 6-8g)

L-Citrulline is a non-essential amino acid that serves as the most effective oral precursor to L-arginine and nitric oxide (NO) — more so than arginine supplementation itself due to superior bioavailability. Clinical trials demonstrate improvements in blood flow, exercise performance, and blood pressure reduction. Citrulline malate (the malic acid-bound form) has additional evidence for reducing muscle soreness and improving high-intensity exercise output.

TL;DR: Converts to arginine and boosts nitric oxide production. Improves exercise performance and blood flow.

💪Muscle & Recovery⚡Energy❤️Heart Health
Last reviewed: 2026-03-12

Quick Facts

Evidence

Grade B

Studies

1

Interactions

2

Forms

1

Evidence Rating: Grade B — Moderate Evidence

Some RCTs with positive results, or strong observational evidence. More research may refine our understanding.

Interaction Warnings

PDE5 inhibitors (Viagra, Cialis)Moderate

Additive blood pressure lowering via nitric oxide

Blood pressure medicationsLow

May enhance hypotensive effects

Important Notes

  • Superior to L-arginine for nitric oxide production
  • Malate form may additionally support ATP production

Clinical Evidence (1 study)

Citrulline malate enhances athletic anaerobic performance

Pérez-Guisado J & Jakeman PM. (2010) — J Strength Cond Res

Increased reps performed and reduced soreness

View on PubMed

Alternatives to Consider

These supplements target similar goals and may be worth considering alongside or instead of Citrulline.

Creatine Monohydrate

Grade A

One of the most researched supplements in history. Strong evidence for strength, power, and emerging evidence for brain function.

💪 Muscle & Recovery⚡ Energy

Beta-Alanine

Grade A

Increases muscle carnosine levels, buffering acid during high-intensity exercise. Well-supported for 1-4 min high-intensity efforts.

💪 Muscle & Recovery⚡ Energy

Taurine

Grade B

Conditionally essential amino acid. Landmark 2023 Science paper showed it extends healthy lifespan in multiple species.

❤️ Heart Health⚡ Energy

Related Supplements

Creatine Monohydrate

Grade A — Strong Evidence

One of the most researched supplements in history. Strong evidence for strength, power, and emerging evidence for brain function.

Beta-Alanine

Grade A — Strong Evidence

Increases muscle carnosine levels, buffering acid during high-intensity exercise. Well-supported for 1-4 min high-intensity efforts.

Potassium

Grade A — Strong Evidence

Critical electrolyte for heart and muscle function. Most people need more, but get it from food — supplemental doses are limited.

Taurine

Grade B — Moderate Evidence

Conditionally essential amino acid. Landmark 2023 Science paper showed it extends healthy lifespan in multiple species.

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⚕️ Important Disclaimer

This information is for educational purposes only. It is not medical advice. Always consult a healthcare provider before starting any supplement regimen, especially if you take medications or have health conditions.

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