L-Citrulline

L-citrulline is an amino acid that your body also makes itself. Food supplies small amounts, with watermelon as the best known source. It belongs to the group of amino acids used around training, alongside glutamine and arginine. In the body, citrulline is converted into arginine. Servings used in the gym run to several grams a day, far more than fruit realistically gives you.

What we can say, and what we cannot

There are no authorised health claims for citrulline in the UK or the EU. EFSA assessed a claim about faster recovery from muscle fatigue for citrulline malate, and that claim was not approved. So you will not read promises on this page. We describe the substance, the forms and how people use it. In sports research the results for performance are mixed rather than settled, which is worth knowing before you buy a large tub.

Powder, capsules and malate 2:1

Two things decide what you actually get: the form and the grams of citrulline per serving.

• Pure L-citrulline powder: unflavoured, mildly sour, you weigh your own dose. Usually the lowest cost per gram.
• Citrulline malate 2:1: citrulline bound to malic acid. Roughly two thirds is citrulline, so 9 g of malate gives about 6 g citrulline.
• Capsules: no taste and easy to take with you, but most hold 500 mg to 1,500 mg, so a multi-gram serving means a handful.

Citrulline also sits inside many ready-made pre-workout blends, often at a modest dose per scoop. Compare the citrulline content on the label, not the scoop size.

How we choose citrulline at BONO

We judge these products on three points: the form, the dose per serving and the combinations that make sense. We prefer labels that state the grams of real citrulline, because a 2:1 malate figure looks stronger than it is. We stock unflavoured powder for people who dose precisely, and capsules for those who travel. We skip pre-workouts that hide half a gram of citrulline inside a blend without numbers. Every product passes our compliance team, we test in house and independent labs spot-check batches. You can read how we select brands.

Purity, origin and storage

In a single-ingredient powder, quality comes down to purity and origin. Nearly all citrulline is made by fermentation, usually from non-GMO glucose or corn, which makes it suitable for vegans. Serious producers publish a certificate of analysis per batch, with purity and checks on heavy metals. Ask for that document if a brand does not show it. Powder draws in moisture and clumps, so keep the tub closed and dry and use a scoop or a small scale.

Who it suits, and who can skip it

Citrulline is mostly bought by people who lift weights or do repeated sprints and intervals. Some also prefer it over supplements with arginine, because they find it easier on the stomach at higher amounts. It suits you less if you want one capsule a day: the studied amounts are large, which makes powder the practical choice. Give it two to four weeks of consistent use before you judge it, and take it 30 to 60 minutes before training on the days you use it.