Gen-Tec Citrulline Malate

Citrulline malate is a straightforward pre-workout choice once you know what the trials actually tested. These are the questions our naturopaths ask in store.

A good fit if

• You lift and you're after more reps in a set rather than a heavier single lift
• You get sore the day after a hard session and want the form used in those trials
• You're happy with a small, average effect rather than a guaranteed one

Check with us first if

• You take blood pressure medicine, nitrates or sildenafil-type medicines. There are no interaction studies, and citrulline acts on the same blood vessel signal.
• You plan to combine it with L-arginine. Together they lowered blood pressure in older adults much more than citrulline alone.
• You're stacking it with several other pre-workout ingredients before very long, hard sessions.

• Citrulline malate. Best known for: Citrulline bonded to malic acid, and the form behind most gym trials. Absorption: Same pathway as pure citrulline. A 6-week trial found no difference from L-citrulline in nitric oxide markers. Typical use: 6 to 8 g of powder before training. A 2:1 product is roughly two-thirds citrulline, and a 1:1 product roughly half.
• L-citrulline (pure). Best known for: The active molecule on its own, so the label weight is the citrulline dose. Absorption: Avoids the breakdown in the gut and liver that limits arginine taken by mouth. Typical use: 3 g a day for blood vessel function in older adults, or 8 g a day over 6 weeks for reps.
• L-arginine. Best known for: The amino acid citrulline turns into, once your kidneys process it. Absorption: Mostly broken down in the gut and liver when swallowed, so it's a poor way to raise blood arginine. Typical use: In Australia, only allowed in listed medicines applied to the skin, not ones you swallow.
• Watermelon. Best known for: The best-known food source of citrulline. Absorption: Not described in our sources. Typical use: Citrulline-rich foods showed no performance effect in pooled trials. It's food, not a measured dose.

Reference values. There's no recommended intake for citrulline. Your body makes it, so it isn't an essential nutrient.

Typical supplemental range. Gym trials mostly used 6 to 8 g of citrulline malate, taken 40 to 60 minutes before training. Depending on the ratio, that's roughly 4 to 5.3 g of actual citrulline. A smaller number of trials used around 3 g of citrulline malate a day for weeks at a time in older adults.

Upper level. An Australian listed medicine can't provide more than 6 g of citrulline a day. No scientific upper limit has been set, because there isn't enough safety data on amino acids like this one to define one.

Worth knowing. Count the citrulline, not the powder. The 6 g cap counts citrulline only, because the malate half is treated as an inactive ingredient. That means a 2:1 product can reach roughly 9 g of powder before it hits the cap, and a 1:1 product roughly 12 g. Some trials used 12 g of citrulline malate, which is around 8 g of citrulline and above that cap. What you need depends on your age, diet and health, so talk to one of our naturopaths.

Food first, where the diet allows it.

• Watermelon: the richest known food source of citrulline itself, not of citrulline malate. A reliable amount per serve wasn't available in our sources

If any of these sound like you, talk to one of our naturopaths or your doctor before you start.

• Blood pressure medicines, nitrates and PDE5 inhibitors such as sildenafil. No interaction study exists. Citrulline works through nitric oxide and lowered blood pressure in older adults, so an added effect is plausible. Check with your doctor or pharmacist.
• Taking it with L-arginine. Together they lowered systolic blood pressure by about 10 mmHg in older adults, far more than either alone. This matters if you take blood pressure medicine.
• Pregnancy. It's only been trialled under specialist supervision for specific conditions, so no general safety conclusion can be drawn. We don't recommend it.
• Breastfeeding. There's no data at all. We don't recommend it.
• Children and teenagers. Only studied in hospital and disease settings. Adult sports doses haven't been studied.
• Heavy stacks with extreme training. One case of exertional rhabdomyolysis (serious muscle breakdown) in a 23-year-old after a long resistance session on a stack that included 10 g of citrulline malate. It wasn't put down to citrulline malate alone, and genetic predisposition wasn't ruled out.
• Dose. An Australian listed medicine can't go over 6 g of citrulline a day, and there's no scientific Upper Level.