Wed Jan 31

Turns out the viral ‘Sleepy Girl Mocktail’ is backed by science. Should you try it?

Written by Charlotte Gupta, Postdoctoral research fellow, CQUniversity Australia

Many of us wish we could get a better night’s sleep. Wouldn’t it be great if it was as easy as a mocktail before bed?

That’s what the latest viral trend might have us believe. The “Sleepy Girl Mocktail” is a mix of tart cherry juice, powdered magnesium supplement and soda water. TikTok videos featuring the concoction have garnered hundreds of thousands of views. But, what does the science say? Do these ingredients actually help us sleep?

Tart cherry juice

There is research ^[2] to show including tart cherry juice in your diet improves overall sleep. Clinical trials ^[3] show tart cherry juice increases sleep quality and quantity, as well as a lessening insomnia symptoms (compared to a placebo). This could be due to the presence of melatonin ^[4], a sleep-promoting hormone, in cherries.

Tart cherry varieties such as Jerte Valley or Montmorency have the highest concentration of melatonin (approximately 0.135 micrograms of melatonin per 100g of cherry juice ^[5]). Over the counter melatonin supplements can range from 0.5 milligram to over 100 milligrams, with research suggesting those beginning to take melatonin start with a dose of 0.5–2 milligrams to see an improvement in sleep ^[6].

Melatonin naturally occurs in our bodies. Our body clock promotes the release of melatonin in the evening to help us sleep, specifically in the two hours before our natural bedtime.

If we want to increase our melatonin intake with external sources, such as cherries, then we should be timing our intake with our natural increase in melatonin. Supplementing melatonin too close to bed ^[7] will mean we may not get the sleep-promoting benefits in time to get off to sleep easily. Taking melatonin too late may even harm our long-term sleep health by sending the message to our body clock to delay the release of melatonin until later in the evening.

Magnesium – but how much?

Magnesium also works to promote melatonin, and magnesium supplements have been shown to improve sleep outcomes ^[8].

However, results vary depending on the amount of magnesium people take. And we don’t yet have the answers on the best dose of magnesium for sleep benefits ^[9].

We do know magnesium plays a vital role in energy production and bone development, making it an important daily nutrient for our diets ^[10]. Foods rich in magnesium ^[11] include wheat cereal or bread, almonds, cashews, pumpkin seeds, spinach, artichokes, green beans, soy milk and dark chocolate.

Bubbly water

Soda water serves as the base of the drink, rather than a pathway to better sleep. And bubbly water may make the mix more palatable ^[12]. It is important to keep in mind that drinking fluids close to bedtime can be disruptive to our sleep as it might lead to waking during the night to urinate.

Healthy sleep recommendations include avoiding water intake in the two hours before bed ^[13]. Having carbonated beverages too close to bed can also trigger digestive symptoms such as bloating, gassiness and reflux during the night ^[14].

Bottoms up?

Overall, there is evidence to support trying out the Sleepy Girl Mocktail to see if it improves sleep, however there are some key things to remember:

timing: to get the benefits of this drink, avoid having it too close to bed. Aim to have it two hours before your usual bedtime and avoid fluids after this time
consistency: no drink is going to be an immediate cure for poor sleep. However, this recipe could help promote sleep if used strategically (at the right time) and consistently as part of a balanced diet. It may also introduce a calming evening routine that helps your brain relax and signals it’s time for bed
maximum magnesium: be mindful of the amount of magnesium you are consuming. While there are many health benefits to magnesium, the recommended daily maximum amounts are 420mg for adult males and 320mg for adult females. Exceeding the maximum can lead to low blood pressure, respiratory distress, stomach problems, muscle weakness and mood problems
sugar: in some of the TikTok recipes sugar (as flavoured sodas, syrups or lollies) is added to the drink. While this may help hide the taste of the tart cherry juice, the consumption of sugar too close to bed may make it more difficult to get to sleep ^[16]. And sugar in the evening raises blood sugar levels at a time when our body is not primed to be processing sugar. Long term, this can increase our risk of diabetes ^[17]
sleep environment: follow good sleep hygiene practices including keeping a consistent bedtime and wake time, a wind-down routine before bed, avoiding electronic device use like phones or laptops in bed, and avoiding bright light in the evening. Bright light works to suppress our melatonin levels in the evening and make us more alert.

What about other drinks?

Other common evening beverages include herbal tisanes or teas, hot chocolate, or warm milk.

Milk can be especially beneficial for sleep, as it contains the amino acid tryptophan, which can promote melatonin production ^[19]. Again, it is important to also consider the timing of these drinks and to avoid any caffeine in tea and too much chocolate too close to bedtime, as this can make us more alert rather than sleepy.

Getting enough sleep is crucial to our health and wellbeing ^[20]. If you have tried multiple strategies to improve your sleep and things are not getting better, it may be time to seek professional advice, such as from a GP.