8 magnesium myths busted – including 'Do I have to put it on my feet?'

Magnesium has a long list of uses in the body – from normal functioning of muscle and nerve function to energy production¹ – and almost as many ways to take or apply it. 

Not necessarily. “Magnesium sprays work by being absorbed into the skin and many claim it helps them unwind by calming the nervous system,” says Madalena. “But the timing doesn’t really matter, as it also works across many other processes like keeping your stress levels in check throughout the day.”

When it comes to whether the spray application itself is responsible for any night-time magic, there are still ongoing studies into the efficacy of ‘transdermal’ – through the skin – magnesium. Many of the studies on this are still too small to be conclusive² and it’s still agreed in the world of science that a balanced diet and oral supplementations are the best ways to experience the benefits of magnesium.^{1, 3}

According to Madalena, most oral magnesium supplements should actually be gentle on your tummy. The only type that might get your stomach gurgling is magnesium oxide. “This is less easily absorbed by your body and is sometimes used to treat constipation⁵ by helping to get things moving,” she explains.

Well, not always. Madalena is well aware of the manic foot-rubbing going on across the internet, “but, I think there’s a placebo effect going on, as there isn’t strong research to back this all up,” says Madalena.

“But if you have pain or muscle cramps in a specific area or you’re struggling with stress, anxiety or sleep problems, putting it on your feet might not be that effective. For topical application, I always suggest using it where you need it – like how my dad uses magnesium cream on his achey knee, or my friend rubs it into her tummy for period cramps,” she says.

It may have found fame for its potential to ease anxiety and promote sleep when applied topically, but that’s only half the story.“Magnesium is sometimes referred to as the sports mineral,” says Madalena. This is partly because it is so essential to muscle function – post-workout, emerging studies

In addition, some researchers⁹ think taking magnesium may also give you the energy to keep pushing, especially during high-intensity workouts. It’s a critical factor in adenosine triphosphate (ATP) production, which provides power to your muscle cells. More research is needed in this area, but it highlights the possibility of magnesium being used in more than just relaxing bath salts.¹¹

Magnesium, when taken alongside adequate water, could also help you rehydrate more efficiently after training. “Alongside sodium, potassium and calcium, magnesium is an essential electrolyte,” says Madalena. Electrolytes are crucial for maintaining the fluid balance in your cells and tissues, ensuring good hydration levels.¹⁰

If only it were this simple! Luckily we’re here to help you navigate the different types of magnesium, including the few main types in the supplement world.

While magnesium itself is essential for everybody, not everyone needs to take extra. “It’s possible to get all the recommended magnesium you need by eating a balanced diet,” says Madalena.

Another bold TikTok claim is that ‘magnesium can help eliminate BO and that magnesium oil can act as a deodorant’. But the science isn’t quite right.

One 2022 study identified that participants gave off an odour ‘similar to stir-fried leeks’ after stressful interview conditions.

Some of the claims about magnesium have become quite stretched, but there are plenty of ways your body uses this essential mineral.