If you're a parent to a young child, no doubt sleep has eluded them (and therefore you) at times.
Loved ones, mothers' groups, and TikTok feeds are full of suggestions about how to get bubs and kids sleeping better and for longer.
One tip doing the rounds is magnesium spray, often marketed as a simple and "natural" solution.
But can topical magnesium really help with kids' sleep? And is it safe?
What is magnesium and do kids need it supplemented?
Magnesium is a mineral that is essential for healthy muscles, nerves, bones and blood sugar levels, and is obtained from food — including green leafy vegetables, legumes and nuts. Generally, foods containing dietary fibre provide magnesium.
Harriet Hiscock is a consultant paediatrician at the Murdoch Children's Research Institute and says it's uncommon to see children with low magnesium levels, with most able to get what they need from a balanced diet.
Professor Hiscock says oral magnesium supplements are not recommended for healthy children.
Pamela Douglas, a Brisbane-based GP and researcher, says magnesium has an important role in a hospital setting, such as being given intravenously for children with severe asthma.
"There are legitimate and important uses of intravenous magnesium, which is part of what is so confusing for parents, because there are legitimate ways in which magnesium helps human health and wellbeing," says Dr Douglas, who is also the medical director of The NDC (Neuroprotective Developmental Care) Institute.
What the research says about magnesium sprays and kids' sleep
Magnesium supplements and topical applications such as creams, oils and sprays are often marketed to help with muscle pain, migraines, and sleep.
Jump into a community Facebook group for mothers, for example, and you'll find anecdotes from parents who spray magnesium oil on the bottom of their child's feet, or rub oil onto their tummy.
But there is no evidence that these products make any difference to sleep in children, Professor Hiscock says.
"If a spray seems to be working, it's likely placebo."
Dr Douglas says using magnesium oils or sprays on children is "not in any way evidence-based" and "there is no rationale for its use around sleep", but she can understand why tired parents would be keen to give it a go.
"It's like a little ritual at bedtime — I can see why that is attractive," adding that by "doing something" about their child's sleep, parents might feel more in control.
Sarah Blunden, an adjunct professor of psychology and paediatric sleep at CQ University, also says there is "very little strong and consistent evidence to support magnesium being strong contributor to better sleep in children".
Is it safe to try anyway?
Magnesium sprays are unlikely to be harmful for children, explains Professor Hiscock.
"There would be little to no absorption from the spray — it has to get through the layers of the skin and into the blood system.
"It won't be harmful, but it won't be useful [either]. Don't waste your money."
Dr Douglas says she doesn't believe the use of topical magnesium is "completely harmless".
"It really shifts attention away from the things that can actually make such a difference around sleep for our families and babies and toddlers.
"That is why it really worries me — it's like another way we often talk about the 'silver bullet' … this is happening in a world where there is so much misinformation about sleep and a lot of advice that makes sleep so much worse than it needs to be."
She says sleep solutions is a "big market" — and market-drive interventions like magnesium mean real problems can be left unaddressed.
Waking during the night is 'normal'
Dr Douglas says it's developmentally normal for babies and toddlers to wake through the night.
"In our society we have this idea that within a few months of life really babies should be going for six to eight-hour blocks without waking, which is just not what the science tells us.
"[And] it's normal for toddlers to wake at night … we just don't want excessive waking."
Professor Hiscock encourages parents to talk to a trusted health professional if they have sleep concerns.
This is general information only. For detailed personal advice, you should see a qualified medical practitioner who knows your child's medical history.
