Pump Juice - non stim Ruthless Raspberry 300g

Citrulline is one of the more straightforward pre-workout ingredients once you know what it does and doesn't do. 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.

• L-citrulline (pure). Best known for: The active ingredient on its own, so the weight on the label is your citrulline dose. Absorption: Raises blood citrulline and arginine, avoiding the breakdown in the gut and liver that limits arginine taken by mouth. Typical use: Studied at 3 g a day for blood vessel function in middle-aged and older adults, and at 8 g a day over 6 weeks for reps.
• Citrulline malate. Best known for: Citrulline bonded to malic acid, and the form used in most gym trials. Absorption: Works the same way. A 6-week trial found no difference from L-citrulline in nitric oxide markers. Typical use: 6 to 8 g before training. A 2:1 product is about two-thirds citrulline and a 1:1 about half, so 8 g of product isn't 8 g of citrulline.
• Watermelon. Best known for: The best-known food source. Absorption: Not described in our sources. Typical use: Citrulline-rich foods showed no effect on performance, and watermelon didn't improve blood vessel measures. It's a food, not a replacement for 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. That's roughly 4 to 5.3 g of actual citrulline, depending on the ratio. Blood vessel trials in older adults used 3 g of L-citrulline a day for 6 to 12 weeks.

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. If a citrulline malate label doesn't give its ratio, you can't work out the dose, so ask us or choose pure L-citrulline. Some trials used 12 g of citrulline malate, which is about 8 g of citrulline and above the Australian 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. 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. There's no interaction study, but citrulline works through nitric oxide and lowered blood pressure in older adults, so an added effect is plausible. Talk to 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're on blood pressure medicine.
• Pregnancy. It has only been trialled under specialist care for specific conditions, and 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. It has only been studied in hospital and illness settings. Adult sports doses haven't been studied.
• Heavy stacks with extreme training. There's one case of exercise-related muscle breakdown (rhabdomyolysis) on a multi-ingredient stack that included 10 g citrulline malate, though it wasn't attributed to citrulline.
• Dose. An Australian listed medicine can't give more than 6 g of citrulline a day, and there's no scientific upper limit.