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

Crossover clinical trial 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

Clinical trial 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 used for?

Citrulline malate combines L-citrulline with malic acid, used in pre-workout and endurance supplements for blood flow (pumps), exercise performance, and reduced fatigue. The citrulline boosts nitric oxide while malate supports energy.

Citrulline malate or pure L-citrulline, what is the difference?

Citrulline malate adds malic acid (involved in energy metabolism) to citrulline, so a given gram amount contains less pure citrulline. Pre-workout studies often use 6 to 8 grams of citrulline malate; pure L-citrulline is used at around 6 grams.

How much citrulline malate should I take?

For workouts, about 6 to 8 grams taken roughly 60 minutes before exercise is common; follow product labeling. A 2-to-1 citrulline-to-malate ratio is typical.

Is citrulline malate safe?

It is generally very well tolerated; high doses may cause mild stomach upset. It may modestly lower blood pressure, so check with your doctor if you take blood-pressure medication.

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. Citrulline raises arginine and nitric oxide; malate participates in the Krebs cycle and may reduce muscle fatigue.

What is the recommended dosage of Citrulline Malate?

The clinically studied dose is 6-8 g pre-exercise (most clinical research dose); 8 g taken 60 minutes before training in Pérez-trial Always follow the product label and check with a healthcare provider for personal advice.

Is Citrulline Malate safe, and does it have side effects?

For most healthy adults, Citrulline Malate is well tolerated at studied doses. Reported effects can include: Generally well-tolerated. GI distress (nausea, abdominal pain) at high doses (>10 g) — usually transient. It may also interact with some medications. Citrulline Malate is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Citrulline Malate interact with any medications?

Possible interactions include: Antihypertensives — additive BP reduction; modest concern. Nitrates (nitroglycerin) — additive vasodilation; theoretical risk; consult. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Citrulline Malate?

NutraSmarts rates the evidence for Citrulline Malate as Moderate (3 out of 5). It is backed by 2 clinical trials and 1 cited reference summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(1 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Aguiar AF, Casonatto J. Effects of Citrulline Malate Supplementation on Muscle Strength in Resistance-Trained Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Diet Suppl. 2022;19(6):772-790..PubMedUsed to support: Meta-analysis supporting citrulline malate for muscle strength in resistance-trained adults.