Also known as: CitMal, L-citrulline DL-malate, Citrulline malate 2:1, Malic acid
Performance & PowerGood evidence
Citrulline bonded to malic acid, and the form most performance research has actually used. The ratio on the label decides how much citrulline you are getting, and plenty of products are quietly short.
Typical dose
6.0–8.0 g per day
45-60 minutes before training
What it is
Citrulline malate combines L-citrulline with malic acid, a compound in the citric acid cycle found naturally in apples.
The ratio is where the confusion lies. A 2:1 product is two parts citrulline to one part malate, so 8 g supplies about 5.3 g of citrulline. A 1:1 product supplies only 4 g from the same 8 g.
Most of the performance research used 2:1 at 8 g. A label saying citrulline malate without stating the ratio is worth treating with suspicion, since 1:1 is cheaper to produce and delivers substantially less of the active ingredient.
How it works
Citrulline converts to arginine in the kidneys, raising blood arginine more effectively than taking arginine directly, and feeding nitric oxide production for vasodilation and blood flow.
Citrulline also participates in the urea cycle, helping clear ammonia produced during intense exercise, which may contribute to reduced fatigue in high-volume sets.
Malate is proposed to contribute independently as a citric acid cycle intermediate supporting aerobic energy production. Evidence for that specific contribution is thin, and most of the effect is reasonably attributed to the citrulline.
What the evidence shows
Trials have reported increases in repetitions completed across multiple sets, particularly in the later sets where fatigue accumulates, alongside reduced soreness in the days following training.
Findings on maximal strength are less consistent, which fits the mechanism: this supports work capacity and blood flow rather than peak force production.
Whether the malate adds anything over plain citrulline has not been established. Given plain citrulline is often cheaper per gram of active ingredient, comparing on citrulline content rather than total powder weight is the sensible approach.
Dosing
Use 8 g of a 2:1 product, which is what the research used and supplies around 5.3 g of citrulline.
If your product is 1:1, you need roughly 10 to 12 g to reach an equivalent citrulline dose. Check the ratio before assuming the scoop is enough.
Take 45 to 60 minutes before training, since the conversion to arginine takes time. It is noticeably sour and acidic, which is the malate, and mixes better in a larger volume of water. It combines well with beetroot or dietary nitrate, since the two raise nitric oxide through separate routes.
Blood arginine peaks around 60-90 minutes after ingestion
Timing
45-60 minutes before training
Competition status
Permitted — not on the WADA Prohibited List
Category
Performance & Power
Safety and side effects
Citrulline malate is well tolerated. Digestive discomfort is the main reported effect at higher doses, and the acidity can cause stomach upset if taken with little water.
Because it promotes vasodilation, it can lower blood pressure modestly. Take care if yours is already being managed.
Speak to your doctor before use if you take regular medication, particularly anything affecting blood pressure or blood vessel dilation.
Who should avoid it
Take care if your blood pressure is being managed. Speak to your doctor before use if you take regular medication, particularly anything affecting blood pressure or blood vessel dilation. Take with plenty of water given the acidity. Not established at supplemental doses in pregnancy or breastfeeding.
This entry is provided for information only. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Consult a qualified healthcare professional before use if you are pregnant, breastfeeding, taking medication or under medical supervision.
