Citrulline Malate

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Evidence summary

Citrulline Malate has strong evidence in this guide. The reference dose is 6-8g before training, with timing listed as 30-60 minutes pre-workout. Supplements should support a sound diet and training plan, not replace them.

• Increases nitric oxide production
• Improves blood flow and muscle pumps

What Is Citrulline Malate?

Citrulline malate is a combination of L-citrulline (an amino acid) and malic acid (involved in energy production). L-citrulline is a precursor to L-arginine, which the body uses to produce nitric oxide — a molecule that relaxes blood vessels and improves blood flow. The malate component may also support aerobic energy production.

How It Works

When you take citrulline malate, your body converts the L-citrulline into L-arginine in the kidneys, which then drives nitric oxide production. This widens blood vessels (vasodilation), increasing blood flow to working muscles. More blood flow means better nutrient delivery, improved waste removal, and those coveted muscle pumps. The malic acid component plays a role in the Krebs cycle, potentially supporting ATP production during exercise.

Interestingly, supplementing with citrulline raises arginine levels more effectively than supplementing with arginine directly, because arginine is heavily broken down in the gut and liver before reaching the bloodstream.

What the Research Says

Multiple studies support citrulline malate at doses of 6-8g for improving exercise performance. Research has shown increases in total reps performed, reduced perceived exertion, and decreased muscle soreness after training. A landmark study found that 8g of citrulline malate increased the number of reps performed on bench press by over 50% across multiple sets.

The evidence is strongest for resistance training involving moderate-to-high reps and for endurance activities. Like most supplements, the effect is meaningful but not dramatic — expect modest improvements, not miracles.

Watch the Dose

Many pre-workout products include citrulline malate but at underdosed amounts (1-3g). The effective dose in research is 6-8g. If your pre-workout contains less than this, you are unlikely to get the full benefit. Buying standalone citrulline malate powder and adding it to your pre-workout is often the smarter (and cheaper) approach.

Who Should Take It

Anyone doing resistance training, CrossFit, or endurance work who wants to improve performance and reduce fatigue. It pairs well with caffeine and beta-alanine as part of a pre-workout stack.

Who Should Skip It

If you are sensitive to stomach discomfort, start with a lower dose (4g) and work up. Otherwise, citrulline malate is one of the most well-tolerated pre-workout ingredients available.

Vegan?

Citrulline malate is vegan-friendly. It is produced synthetically and contains no animal-derived ingredients. The name comes from citrullus (watermelon), where L-citrulline was first identified.

Where to Buy

• Bulk Citrulline Malate 2:1 — from £9.99
• Myprotein Citrulline Malate — from £11.99
• Amazon — Nutricost Citrulline Malate — from £13.99

Citrulline Malate: common questions

What is citrulline malate used for?

Citrulline Malate is commonly considered for increases nitric oxide production, improves blood flow and muscle pumps, may reduce fatigue, enhances endurance performance. The evidence rating in this guide is strong.

When should I take citrulline malate?

The practical timing used in this guide is 30-60 minutes pre-workout. Consistency and the total daily dose are often more important than a narrow timing window.

How much citrulline malate should I take?

The reference dosage in this guide is 6-8g before training. Individual needs vary, so check the product label and speak to a qualified healthcare professional if you have a medical condition, take medication, are pregnant, or are unsure.

Is citrulline malate vegan friendly?

This form of citrulline malate can be vegan friendly, but check the capsule, flavouring, and manufacturing details on the specific product.

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