Know2eat

Citrulline malate

Amino Acids & Proteins

What citrulline malate may help with

Ranked by how strong the human evidence is — best supported first.

Best supportedExercise performanceLimited evidence· 3 sources

Then, in order

About Citrulline malate

A salt of citrulline and malic acid, usually in a 2:1 ratio by weight — so 8 g of citrulline malate supplies roughly 5.3 g of citrulline and 2.7 g of malate.

Citrulline malate is the form most performance trials actually used, which is why it appears separately here. The most-cited study reported that 8 g before a chest workout increased repetitions to failure by around 50% in the later sets and reduced soreness — an effect size so large that subsequent replication attempts, several of which found nothing, are the more informative part of the literature. The malate half is usually credited with a role in the citric acid cycle; no trial has separated malate from citrulline to test whether it contributes anything at all.

Sold as
Powder, Pre-workout blend component, Capsule
Standardised to
Ratio of citrulline to malate — 2:1 in most trials, but 1:1 products exist and supply less citrulline per gram — a product without this marker may not resemble what was studied.
Also known as
Citrulline malate 2:1, CitMal

Regulation: Sold as a dietary supplement with no pre-market efficacy review. Not prohibited in sport, with the usual contamination caveat for tested athletes buying pre-workout blends.

What the research used

The amounts, forms and durations published trials of Citrulline malate actually administered.

These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.

  • Studied for Resistance training volume

    8 g

    Limited

    Citrulline malate 2:1, 60 minutes before training

    The dose in the frequently cited trial reporting large increases in repetitions to failure. Replication attempts have produced much smaller or null results, and 8 g supplies roughly 5.3 g of citrulline.

  • Studied for High-intensity endurance

    6–12 g

    Not enough

    Citrulline malate before exercise

    Doses vary widely across small trials with inconsistent results. Where products state only "citrulline malate", the actual citrulline content depends on an undeclared ratio.

This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.

When it was taken

Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.

Each timing below was actually compared against an alternative in a trial, which is unusual.

  • Before exercise

    Moderate

    Dosed 40–60 minutes before exercise in trials, matching the time to peak plasma arginine after citrulline ingestion. The pharmacokinetic basis is measured; the performance benefit it is meant to produce is the uncertain part.

    Timing was tested. A trial compared this window against another and reported a difference.

The evidence in depth

Best supported: Limited

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.

Exercise performance

Muscle & Physical Performance
Limited evidence

One widely cited trial reported a large increase in resistance training repetitions with 8 g before a session. Attempted replications have generally found much smaller or no effects, and meta-analyses that pool citrulline and citrulline malate report small average benefits with high heterogeneity.

Limited evidence. Early human work, or mostly lab and animal research.

View the 3 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Exercise recovery

Muscle & Physical Performance
Not enough evidence

Reduced muscle soreness has been reported in the same small trials that reported the performance effects, using self-rated soreness scales. There is not enough consistent evidence to support a recovery claim.

Not enough evidence. Not enough human research to say anything useful yet.

View the 3 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Things to know

Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.

  • Interaction

    Additive hypotension with nitrates and PDE5 inhibitors

    Interacts withNitrates, PDE5 inhibitors, antihypertensives

    The citrulline component raises nitric oxide availability, so the same interaction caution applies as for citrulline and arginine.

  • Worth knowing

    The ratio is often undeclared

    A 1:1 product supplies substantially less citrulline per gram than the 2:1 material used in trials. Products in proprietary pre-workout blends frequently disclose neither the ratio nor the amount.

  • Too much

    Stomach discomfort at 8 g

    Gastrointestinal upset was reported by roughly one in seven participants in the original trial at this dose, which is the practical limit for many people.

Evidence ratings on this page: 1 limited evidence, 1 not enough evidence.

Supplements are sold in the US without pre-market review of efficacy or safety. Nothing on this page is a recommendation to take Citrulline malate, or a dose to follow.