It depends on what you want it for and how sensitive your digestion is. Magnesium bisglycinate is the gentlest and most widely recommended for everyday use. Citrate is well absorbed and a good general option, though it can have a mild laxative effect at higher amounts. Malate is often chosen by people supporting energy levels, as malate is part of the body's energy production cycle. Magtein magnesium L-threonate is the form studied for its ability to cross into the brain. If you are unsure, bisglycinate is the safest starting point, or ask a practitioner.

Magnesium contributes to normal functioning of the nervous system and to normal psychological function, and many people choose to take it in the evening as part of a wind-down routine. There is no authorised health claim for magnesium and sleep, so we do not make one. What we can say is that bisglycinate is the form most often used for this purpose because it is gentle and well tolerated late in the day.

The UK reference intake is 375mg a day for adults, from food and supplements combined. Our labels give a suggested serving for each product, and most people do not need to exceed it. If you take more than the label recommends, split it across the day and take it with food to reduce the chance of loose stools. Anyone with kidney problems, or taking medication, should check with a healthcare professional first.

Capsules are convenient and give a fixed amount per serving. Our ionic magnesium liquids and Magnesium XS let you measure by the drop, which suits people who want to build up gradually, split a dose, or take a smaller amount for a child. Liquids are also the answer for anyone who cannot swallow capsules.

Magnesium pairs naturally with vitamin D3, which supports calcium and magnesium absorption, and with B vitamins for energy metabolism. Take it a couple of hours apart from high-dose calcium, iron or zinc if you are supplementing those as well, since they compete for absorption. If you are on prescription medication, particularly antibiotics, diuretics or medication for osteoporosis, ask your pharmacist about timing.