Home Ingredients Citrulline Malate
Athletic Performance

Citrulline Malate

Evidence Level
Moderate
2 Clinical Trials
5 Documented Benefits
3/5 Evidence Score

Citrulline malate is a 1:1 or 2:1 ratio of L-CITRULLINE and MALATE (malic acid) — used extensively in performance and bodybuilding contexts. Citrulline raises arginine and nitric oxide; malate participates in the Krebs cycle and may reduce muscle fatigue. Original 1980s European research positioned it as 'asthenia' (fatigue) treatment; modern use is primarily for exercise performance, muscle pumps, and reducing post-exercise soreness.

Studied Dose 6-8 g pre-exercise (most clinical research dose); 8 g taken 60 minutes before training in Pérez-trial
Active Compound L-Citrulline (amino acid) + DL-Malate (malic acid salt)

Benefits

Resistance Training Performance

Pérez-RCT showed citrulline malate 8 g pre-workout significantly increased reps to failure on bench press (+18%) vs placebo. Multiple subsequent trials confirm modest performance benefits in resistance training.

Supported by Trial 1, Trial 2

Reduced Post-Exercise Soreness

Pérez-Guisado 2010 also showed 40% reduction in muscle soreness at 24-48 hours post-exercise vs placebo. Mechanism: improved blood flow, ammonia clearance, ATP regeneration support via malate.

Supported by Trial 1

Endurance / Aerobic Performance Modest Effects

Some trials show modest endurance improvements; effect smaller than resistance training benefits. trial showed improved cycling time-trial performance.

Supported by Trial 2

Increased Plasma Arginine and NO

Citrulline raises plasma arginine more effectively than oral arginine itself (citrulline bypasses first-pass intestinal arginase). Increased arginine supports nitric oxide synthesis. Foundational pharmacology for vasodilation and 'pump' effects.

Supported by Trial 1, Trial 2

Erectile Function (Modest)

trial showed L-citrulline 1.5 g/day improved mild erectile dysfunction. Mechanism: NO pathway support. Effect smaller than PDE5 inhibitors but reasonable for mild ED.

Supported by Trial 2

Mechanism of action

1

Citrulline-to-Arginine Conversion

Oral L-CITRULLINE is converted to L-ARGININE in the kidney via argininosuccinate synthase + lyase. Bypasses intestinal arginase that breaks down oral arginine — citrulline raises plasma arginine MORE effectively than oral arginine itself. Arginine is substrate for nitric oxide synthase.

2

Nitric Oxide / Vasodilation

Increased arginine → increased nitric oxide → vasodilation, increased blood flow, improved nutrient and oxygen delivery to muscles. Mechanism for 'pump' effects and endurance support.

3

Malate / Krebs Cycle Substrate

Malate (malic acid) is intermediate in Krebs cycle (citric acid cycle) — supports ATP regeneration. Theoretical contribution to fatigue resistance.

4

Ammonia Clearance (Urea Cycle)

Citrulline is intermediate in urea cycle; supplemental citrulline supports clearance of ammonia (a fatigue metabolite). May contribute to performance effects.

Clinical trials

1
Citrulline Malate for Resistance Performance — Pérez-Guisado 2010
PubMed

Crossover RCT of citrulline malate (8 g, 60 min pre-workout) vs placebo for chest workout performance.

41 men.

Significant 18% increase in repetitions to failure on bench press; 40% reduction in soreness at 24-48 hours. Foundational evidence; widely-cited in supplement formulation.

2
Citrulline Malate for Cycling Performance — Bailey 2015
PubMed

RCT of citrulline malate (12 g/day for 7 days) on cycling time trial performance.

12 men.

Modest improvement in 4-km time trial performance and reduced perceived exertion. Effect smaller than resistance training benefits.

Side effects and drug interactions

Common Potential side effects

Generally well-tolerated.
GI distress (nausea, abdominal pain) at high doses (>10 g) — usually transient.
Hypotension in sensitive individuals.
Headache rare.
Theoretical drug interactions via NO pathway.

Important Drug interactions

Antihypertensives — additive BP reduction; modest concern.
Nitrates (nitroglycerin) — additive vasodilation; theoretical risk; consult.
PDE5 inhibitors (sildenafil, tadalafil, vardenafil) — additive NO/vasodilation; theoretical hypotension; consult.
Anticoagulants — minimal interaction.
ACE inhibitors — minimal interaction.
Pregnancy/lactation — limited supplementation safety data; AVOID concentrated doses.
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Frequently asked questions about Citrulline Malate

What is Citrulline Malate?

Citrulline malate is a 1:1 or 2:1 ratio of L-CITRULLINE and MALATE (malic acid) — used extensively in performance and bodybuilding contexts.

What does Citrulline Malate do?

Oral L-CITRULLINE is converted to L-ARGININE in the kidney via argininosuccinate synthase + lyase. Bypasses intestinal arginase that breaks down oral arginine — citrulline raises plasma arginine MORE effectively than oral arginine itself. In clinical research, Citrulline Malate has been studied for resistance training performance, reduced post-exercise soreness, endurance / aerobic performance modest effects.

Who should take Citrulline Malate?

Citrulline Malate may be most relevant for people interested in athletic performance. It has been clinically studied for resistance training performance, reduced post-exercise soreness, endurance / aerobic performance modest effects. As with any supplement, consult your healthcare provider before starting, especially if you have medical conditions or take prescription medications.

How long does Citrulline Malate take to work?

Most clinical trial effects appear over weeks of consistent use; individual response varies. Acute or same-day effects (where applicable) typically appear within hours, but most cumulative benefits — particularly those affecting biomarkers, mood, sleep quality, or chronic symptoms — require 4-12 weeks of regular use to fully assess. If you don't notice benefit after 12 weeks at the appropriate dose, it may not be your responder.

When is the best time to take Citrulline Malate?

For performance or energy goals, Citrulline Malate is typically taken 30-60 minutes before exercise or in the morning. Some people take it with food to reduce GI sensitivity; others prefer empty-stomach timing for faster absorption. Always check product labeling and follow personalized guidance from your healthcare provider.

Is Citrulline Malate worth taking?

Citrulline Malate has moderate clinical evidence (Evidence Level 3/5 on NutraSmarts) — meaningful trial support exists, though results are less consistent than top-tier ingredients. Whether it's worth taking depends on your specific goals, what you've already tried, your budget, and your overall supplement strategy. The honest framing: no supplement is essential for most people, and lifestyle factors (sleep, exercise, diet, stress management) typically produce larger effects than any single supplement. Citrulline Malate is most worth trying if its evidence-supported uses align with your specific goals.

What is the recommended dosage of Citrulline Malate?

The clinically studied dose for Citrulline Malate is 6-8 g pre-exercise (most clinical research dose); 8 g taken 60 minutes before training in Pérez-trial. Always follow product labeling and consult a healthcare provider for personalized dosing recommendations.

What is Citrulline Malate used for?

Citrulline Malate is studied for resistance training performance, reduced post-exercise soreness, endurance / aerobic performance modest effects. Pérez-RCT showed citrulline malate 8 g pre-workout significantly increased reps to failure on bench press (+18%) vs placebo. Multiple subsequent trials confirm modest performance benefits in resistance training.