Magnesium pills: Are you taking the right ones for sleep?

Indian Express

06-06-2025

When one of his patients ended up having bad stomach cramps, diarrhoea and dehydration, Dr Balakrishna G K, HOD & Sr Consultant Internal Medicine, Gleneagles BGS Hospital, Bengaluru, was stumped. Till he found that he had taken magnesium citrate — commonly used in hospitals to flush out the bowels before procedures. 'He had taken it thinking it would help him sleep since he had read that magnesium supplements helped people sleep better. Each supplement has a different compound for a specific purpose,' he says.
Magnesium is suddenly everywhere — promoted as a fix for sleep troubles, stress, brain fog, and muscle cramps. 'But what many people don't realise is that magnesium isn't a one-size-fits-all solution. There are different forms of it, each with distinct purposes, and using the wrong one can create more problems than it solves,' says Dr Balakrishna.
Which magnesium supplement is good for sleep?
Magnesium glycinate is something we often recommend when someone with a magnesium deficiency is dealing with stress or struggling to sleep. It has a gentle, calming effect and doesn't usually upset the stomach, which makes it easier to take over time. But people should know it's not a sleeping pill. At best, it can help the body unwind, but it won't replace the need for proper sleep hygiene or medical intervention when necessary. In fact, the reason some people feel it 'works' is because they start pairing it with a better wind-down routine. That's more behavioural than pharmacological.
Which supplement should not be ingested?
Another form, magnesium sulfate — or Epsom salt — is meant only for external use in baths to soothe sore muscles. It's not meant to be ingested.
Magnesium L-threonate, which has been hyped for its cognitive benefits, is still being researched — and we simply don't have enough data yet to call it effective.
Why the confusion about magnesium supplements?
Many supplement bottles don't mention which form or compound is inside. Often, products simply say 'Magnesium 400 mg' without revealing the compound — and in many cases, that's magnesium oxide. This is one of the cheapest forms available and frequently used in commercial supplements. But it also has poor bioavailability, which means the body absorbs only a small fraction of what's on the label. So people think they're correcting a deficiency, when in reality, they may not be absorbing enough to make a difference.
Get magnesium from food
Magnesium from food is almost never harmful — the body has a natural way of regulating how much it absorbs. But supplements can easily overshoot the mark, especially if taken without medical supervision. Nuts, seeds, whole grains, legumes, and leafy greens are excellent dietary sources and should always be the first line of replenishment. The recommended daily dosage for adults is between 310-420 mg per day.
Who should not take supplements
If someone has kidney issues, magnesium supplements aren't something to take lightly. The kidneys play a big role in clearing excess magnesium from the body. When they're not functioning well, magnesium can quietly build up in the system without any early red flags — and that can become risky before anyone even knows something's wrong.
There's also a drug interaction angle that often gets missed. Magnesium can interfere with the absorption of thyroid medications, certain antibiotics, and even some blood pressure pills. Supplements can be helpful — but only when the form, dose, and purpose are aligned with actual needs.