L-Citrulline

Amino Acid

Also known as: Citrulline, Citrulline malate

Grade B

💊 3-6 g citrulline or 6-8 g citrulline malate🎯 4 primary uses🔗 2 synergies⚠️ Review warnings

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Levels upFitness+50 pts

Overview

More effective nitric oxide booster than arginine. Converts to arginine while bypassing liver metabolism.

Primary Uses

Blood flowExercise performanceCardiovascular healthPump

Frequently Asked About L-Citrulline

How much L-Citrulline should I take?

The typical effective range is 3-6 g citrulline or 6-8 g citrulline malate. Individual needs vary based on age, body weight, diet, and goals — start at the lower end and adjust based on response. Always consult a healthcare provider before starting a new supplement.

When is the best time to take L-Citrulline?

30-60 min before exercise. Consistency matters more than perfect timing — pick a daily anchor (e.g. with breakfast or before bed) and stick with it.

Should I take L-Citrulline with food?

Optional.

Does L-Citrulline interact with medications?

Yes — known interactions include BP meds, nitrates - caution. If you take any prescription medication, talk to your doctor or pharmacist before starting L-Citrulline.

What does L-Citrulline pair well with?

L-Citrulline stacks well with Arginine and Beetroot — these combinations either improve absorption or work synergistically toward common goals.

Who should not take L-Citrulline?

L-Citrulline should be avoided or used with caution by people with None. Pregnant or breastfeeding women should consult a healthcare provider before use.

What are the side effects of L-Citrulline?

Most people tolerate L-Citrulline well. The most commonly reported side effects are Well tolerated. Side effects are usually dose-dependent — lowering the dose often resolves them.

Dosage

Typical range

3-6 g citrulline or 6-8 g citrulline malate

Timing

30-60 min before exercise

With food

Optional

Duration

Safe long-term

Special Populations

Athletes, blood flow support

Research & Studies

Search the literature now

We haven’t curated landmark studies for L-Citrullineyet — one-click into the primary literature here. PubMed (RCTs) is usually the highest-signal starting point.

Search L-Citrulline research

PubMed (RCTs) ↗Randomized trials PubMed (all) ↗Full literature Cochrane Reviews ↗Systematic reviews Examine.com ↗Research summaries

Browse all curated studies →

Mechanism of Action

• Converts to arginine in kidneys
• Bypasses hepatic metabolism
• More sustained NO production

Evidence Quality

Evidence Grade B

Superior to arginine for NO production

Safety & Contraindications

Serious Warnings

• None significant

Contraindications

• None

Common Side Effects

• Well tolerated

Pregnancy & Breastfeeding

Consult healthcare provider

Liver & Kidney Notes

Safe

Interactions

💊 Medications

• BP meds, nitrates - caution

🧪 Supplements

• Can combine with arginine

🍽️ Food & Alcohol

• Watermelon is source

Stacking & Synergies

Pairs Well With

Arginine ↗Beetroot ↗

Avoid Combining With

None

Best Goal Synergies

Exercise performancePumps

Buying Guide

What to Look For

• Form specified

Standardization Markers

Pure citrulline vs malate

Adulteration risk

Low

Practical Notes

• Better absorbed than arginine
• Found in watermelon

Related Guides

In-depth guides covering L-Citrulline — protocols, comparisons, and use cases.

Pre-Workout Supplement Protocol↗

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Last reviewed: September 2026 by the Formulate Research Team. Sources cited above; methodology and scoring criteria published here.

Cite this page

Formulate Research Team. (2026, September). L-Citrulline — Evidence-Based Supplement Guide. Formulate Supplement Encyclopedia. https://app.formulate-health.app/learning/supplements/l-citrulline

Educational content based on published research and our scoring methodology. Not medical advice — consult a qualified healthcare provider before starting, stopping, or changing supplements, especially if you take medications, are pregnant, or have a medical condition.