Popular supplement taken by millions triggering bizarre sleep side effect – and dosage that wrecks your sleep

Credit: Getty DO you struggle with rubbish kip? Then you’ve likely heard of magnesium – dubbed a ‘magic mineral’ for insomniacs and restless sleepers. It’s an essential mineral that helps the body function properly. Nearly 300 chemical reactions in the body rely, at least in part, on magnesium, which helps maintain a healthy cardiovascular system, nerves, muscles, and bones. Sign up for the Health newsletter Thank you! With studies showing magnesium deficiencies could be linked to poor sleep, the supplement is touted as a sleep saviour – supposedly helping people who usually toss and turn at night to calm the noise in their brain and drift off. It’s also been suggested that magnesium can help regulate melatonin, a hormone produced by your body when it’s dark. Evidence for these two claims is limited, but it hasn’t stopped millions of people from buying magnesium supplements to help sort out their sleep issues – often spurred on by social media. Though the popular supplement seems to be helping many poor sleepers finally get some rest, it has been linked to a bizarre side effect: weird and wacky dreams. The strange phenomenon even has a dedicated Subreddit thread, called r/magnesium, where people share peculiar symptoms they’ve noticed after popping the so-called miracle supplement. “It helps me sleep, but the dreams are insane,’ one user wrote after they were prescribed it by their doctor for muscle recovery. Most read in Health “The vivid dreams are crazy, and they really mess me up sometimes.” Another said they had to stop taking magnesium after experiencing the “worst nightmare[s] ever”, likening them to “horror movies with me playing the main role”. “Vivid dreams or nightmares are VERY common when you first start taking magnesium,” a third user shared. “Good news: they should taper off relatively quickly.” On Reddit, theories abound as to what causes vivid and scary dreams – from dosage, to different forms of magnesium, or deficiencies in other minerals. But what do health experts have to say about it? Dr Nikki Ramskill, Doctify-­rated GP and founder of The Female Health Doctor Clinic, tells Sun Health: “Magnesium supplements have become really popular to help with sleep and some people report having unusually vivid, strange or memorable dreams after taking them. “I would say that this isn’t a well-established side effect of magnesium and we don’t currently have good evidence showing that magnesium directly causes vivid dreams.” This is echoed by hormone and women’s health specialist Dr Shirin Lakhani, who says: “Although certain forms of magnesium can be beneficial for nervous system support, feeling calmer and easing stress – which in turn can aid in sleep – there is not enough evidence to support any claims that it changes the intensity of your dreams.” Dr Ramskill says: “One possible explanation is that magnesium plays a role in neurotransmitter activity, including pathways [that help] regulate relaxation and sleep. A mature woman in her 40s sitting up in bed clutching her comforter with a worried look on her face. She looks like she had a bad dream. Or perhaps she is sick with the flu. Credit: Getty Should you be taking magnesium for sleep? Dr Lakhani says: “Magnesium plays a role in nervous system regulation, muscle relaxation and sleep quality. “It isn’t a sedative, but it may support a calmer state that’s more conducive to sleep. “It is important to keep in mind, howeve, r that not all magnesium helps with sleep. “Magnesium L-Threonate, for exampl, e is a highly absorbable form of magnesium that supports nervous system function and is beneficial for aiding good-quality sleep.” But she notes: “For most people, I wouldn’t recommend taking a magnesium supplement simply because they want to influence their sleep.” Dr Ramskill adds: “I’d be cautious about viewing magnesium as a proven sleep remedy. “Although it’s become extremely popular on social media, research into magnesium supplementation for sleep remains limited and inconsistent.” “If someone sleeps more deeply, wakes less frequently or experiences a change in their sleep pattern, they may notice or remember their dreams more than they normally would. “That can create the impression that the magnesium itself is producing the dreams.” There are several sleep stages, but rapid eye movement (REM) sleep is when the most vivid and intense dreams occur. According to the National Institutes of Health, getting fewer hours or interrupted sleep can eat into the REM stage, cutting into dream-time. But when you get a good chunk of uninterrupted amount of REM sleep – one cycle is about 90 to 120 minutes – you’re more likely to remember dreams. For many, popping magnesium supplements can help them tap into more REM time, resulting in vivid dreams they can easily recall. That’s because you spend more time in this dream-heavy stage, but also because REM sleep has been shown to boost memory and brain recovery. In some cases, magnesium won’t be the cause of your wacky dreams, the experts add. “Some magnesium supplements also contain other ingredients, such as vitamin B6, so it is worth checking the label rather than assuming magnesium is responsible,” says Dr Ramskill. As far as dosage is concerned, “there isn’t a particular dose of magnesium that’s been shown to trigger vivid dreams”, the GP adds. She recommends taking less “to see what happens” if you are plagued by particularly weird dreams. “In terms of dosage, it’s also important to distinguish between how much magnesium we need overall and how much we should take as a supplement,” she adds. “In the UK, women aged 19–64 need around 270mg of magnesium per day and men 300mg. “Most people should be able to obtain this through a varied diet.” Several foods are rich in the nutrient, so you can get all you need from eating nuts, seeds, wholegrains, beans and leafy green vegetables,” says Dr Lakhani. “I would never recommend blind supplementation.” If you do go down the supplement route, don’t have more than 400mg a day as it can cause diarrhoea, nausea and stomach cramps. “At very high intakes, it can cause much more serious toxicity, particularly in people with impaired kidney function,” Dr Lakhani adds. Dr Ramskill notes: “People should check the amount of actual or ‘elemental’ magnesium in their supplement rather than assuming that a larger number on the front of the packet means they need that amount.” She concludes: “For most people, vivid dreams on their own aren’t something to worry about. “If they’re unpleasant, causing repeated nightmares or disrupting sleep, I’d suggest stopping the supplement for a week or two and seeing whether they disappear. “If significant sleep disturbance continues without the supplement, that’s worth discussing with a doctor.” People with kidney disease should also be particularly cautious of magnesium, because their body may be less good at removing excess amounts of it. “Anyone with kidney disease, or who takes regular medication, should speak to their doctor or pharmacist before taking magnesium,” Dr Ramskill warns Comment now