Walk into any pharmacy, health store or trendy cafe and you’ll see rows of magnesium on sale, offered in every variety from tablets and powders to fizzy drinks.

Magnesium has become a buzzword in the wellness industry and barely a week goes by without a woman asking me whether she ought to be taking it and in what form.

So let’s try to separate the science from the hype.

Firstly, it isn’t some influencer fad.

Magnesium is one of the most important minerals our bodies need, involved in hundreds of processes that keep us ticking over, from turning food into energy to keeping our muscles working.

About 60 per cent of it is stored in our bones.

The problem is that we can’t make it ourselves and so we have to get it through our diet, with a surprising number of us not getting enough.

Surveys suggest the average British woman gets only around 238mg a day from her food when she should be getting 270mg.

Among older adults, roughly one in six have low levels that could potentially cause issues, especially in women over 50.

As oestrogen drops away during the menopause, the body seems to handle magnesium less efficiently, with levels dipping at the very moment life is throwing hot flushes, broken sleep and low mood at you.

There’s decent evidence too that magnesium helps keep bones strong, which matters enormously once oestrogen disappears after the menopause.

And it may ease migraines, and that grinding premenstrual irritability so many women dread.

Something many women don’t realise though, is that alcohol has a negative impact on magnesium.

It acts like a diuretic, flushing it out through the kidneys.

That nightly glass we reach for to take the edge off the day is quietly sending a little more of this precious mineral down the loo.

The more you drink, the more you lose, so if your levels are already running low, the booze won’t help.

Magnesium supplements are mostly associated with improving sleep.

A big review in 2021 found that older people taking magnesium fell asleep about 17 minutes faster, and slept a little longer than those handed a dummy pill.

Helpful, but hardly the overnight miracle those pushing the supplement claim.

The theory is that it gently nudges up a calming brain chemical called GABA, the same system prescription sleeping tablets act on.

However, some scientists argue that unless you’re short of magnesium to begin with, any extra simply gets passed out in your urine.

Much of the sleep benefits people claim to experience are likely to be the placebo effect doing its quiet, powerful work.

I should make a confession here; I sometimes take it myself.

I started after an episode of jet lag following a long-haul flight and have found it useful ever since.

It seems to give me a deeper, longer sleep.

Am I sure it isn’t the placebo effect? No, but when my body clock is all over the place after travelling, it helps me drop off and that’s good enough for me.

Things get trickier when it comes to mood and anxiety.

Low magnesium has been linked to a higher risk of depression,....