Active Magnesium Citrate

Our naturopaths reach for citrate when you want good absorption and either don't mind softer bowels or would actually like that. These are the questions they ask in store, in the same order.

A good fit if

• You want a well-absorbed everyday magnesium and your bowels tend to be on the slow side
• You're moving on from a magnesium oxide blend and want something that dissolves properly
• You'd rather stir a powder or fizzy tablet into water than swallow capsules
• You're happy to split your daily amount into two or three doses
• Your kidneys are healthy and you don't take any medicine that needs to be spaced away from minerals

Check with us first if

• You're taking magnesium mainly for sleep or to relax your muscles in the evening. One big citrate dose at bedtime is the classic mistake, and glycinate usually suits better.
• You already tend to have loose stools, or you have a diagnosed bowel condition. The effect will add up.
• The product is a blend. Check whether magnesium oxide or carbonate is doing most of the work, because those are the forms most often linked to diarrhoea.
• You're using a sachet that gives you 400 mg of actual magnesium in one serve, which is above the NHMRC upper limit for supplements.
• You take bisphosphonates, tetracycline or quinolone antibiotics, diuretics (water tablets) or long-term reflux medicine (a proton pump inhibitor). The spacing and monitoring apply to every form of magnesium and are set out on our magnesium page.
• You take any prescription medicine. A quick check with your doctor, pharmacist or our naturopaths first is the sensible step.

• Magnesium citrate (Schedule 1 item 3153). Best known for: The standard entry on Australian labels, often printed as tri-magnesium dicitrate. Absorption: Dissolves easily and is absorbed more completely than magnesium oxide or sulfate. Typical use: Tablets, capsules, effervescent tablets and sachet powders.
• Magnesium citrate nonahydrate (item 3154) and tetradecahydrate (item 3155). Best known for: Hydrated crystal forms, with nine or fourteen water molecules built in. Absorption: Once dissolved, they're identical: the same citrate and the same solubility. Typical use: A manufacturing choice for powders and effervescent formats; the water means less magnesium in each milligram of raw material.
• Dibasic magnesium citrate tetrahydrate (item 1776). Best known for: A different ratio: one magnesium per citrate rather than three per two. Absorption: A soluble organic salt, in the same family as the others. Typical use: Only allowed in medicines taken by mouth.
• Levocarnitine magnesium citrate (item 3011). Best known for: A combined carnitine-and-magnesium salt rather than a magnesium supplement. Absorption: Carries both actives in one molecule; magnesium isn't the main point. Typical use: Sports and energy formulas; check the elemental magnesium line before you compare.
• Citrate blended with magnesium oxide. Best known for: The most common real-world label: an oxide base with citrate named on the front. Absorption: Mixed. The oxide part absorbs poorly and is the part most often linked to loose bowels. Typical use: Blended tablets and powders. The oxide counts toward the inorganic-salt warning threshold, so these can carry a laxative statement that a pure citrate doesn't.

Reference values. The NHMRC's recommended amounts are for magnesium itself, not any one form, and the full list by age and sex is on our magnesium page. A citrate label shows the weight of the whole compound first, and the actual (elemental) magnesium on a separate line further down the panel.

Typical supplemental range. Australian citrate products usually list 900 mg of magnesium citrate per tablet or capsule, and you take two or three a day. Single-serve sachet powders sit at the other end and can give you 400 mg of actual magnesium in one drink.

Upper level. The NHMRC upper limit for magnesium from supplements is on our magnesium page, and it applies whatever the form. A 400 mg single sachet is above that limit, so it's worth a chat before you buy rather than after.

Worth knowing. Splitting your dose is the simple fix with citrate. The same daily amount taken in two or three parts, with food, is far less likely to loosen your bowels than one big dose at night. No food contains magnesium citrate as such; it's a form chosen by the manufacturer. What you need depends on your age, diet and health, so talk to one of our naturopaths.

Food first, where the diet allows it.

• Potato, baked with skin: about 43 mg of magnesium per 100 g
• Brown rice, cooked: about 42 mg per half cup
• Yoghurt, plain, low fat: about 42 mg per 227 g tub
• Banana: about 32 mg per medium banana
• Wholemeal bread: about 23 mg per slice
• Avocado, cubed: about 22 mg per half cup

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

• Reduced kidney function or kidney failure. Your body can't clear excess magnesium, so it can build up; don't supplement without medical supervision.
• Babies under 12 months. These magnesium salts must not be directed for use under 12 months of age.
• Abdominal pain, nausea, vomiting or diarrhoea you already have. The mandatory label statement says not to use it then.
• A tendency to loose stools, or a diagnosed bowel condition. The water-drawing effect adds to it.
• Taking magnesium for sleep in one large evening dose. Citrate is the wrong form for that job.
• Blended products containing magnesium oxide or carbonate. Those salts are the ones most often reported to cause diarrhoea, and they can trigger the laxative warning statement.
• Single sachets supplying 400 mg of elemental magnesium. That's above the NHMRC upper limit for supplemental magnesium.
• Bisphosphonates, tetracycline and quinolone antibiotics, diuretics and long-term proton pump inhibitors. See our magnesium page.
• Taking more than the label dose. Extremely high intakes can lead to an irregular heartbeat and cardiac arrest.
• Constipation lasting more than a few days. Stop and talk to your health professional.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths before you start.