If you’ve been on TikTok in the past couple of years, you’ve probably come across the Sleepy Girl Mocktail. It’s one of TikTok favorite wellness beverages that sounds just about good enough to be plausible. Tart cherry juice, magnesium powder, and some probiotic soda or lemon. It puts you to sleep, no more restless nights, or doom-scrolling at 2 am.

Although tart cherry juice supports sleep quality due to its increased tryptophan availability. It also have melatonin, magnesium makes you relax, and who doesn’t love a little carbonation? But not all magnesium are the same. Downing magnesium citrate before bed and hoping for a good peaceful night might get you in for an unpleasant, toilet-bound awakening. Magnesium citrate isn’t a sleep aid when taken in certain amounts, because it’s a laxative.

If you’ve ever wondered why some magnesium supplements leave you glued to the toilet, you might want to double check next time, this is the same thing doctors prescribe when they need to clear out your intestines before a colonoscopy.

Not All Are Created Equal

Magnesium is a crucial mineral—it’s involved in over 300 biological functions, including muscle relaxation, transporting electrolytes across cells, and regulating blood pressure. The body needs about 320 mg a day if you’re a woman and 420 mg if you’re a man ( you might want to check with your doctor for your specific needs), and unless your diet is packed with leafy greens, nuts, and whole grains, you’re probably not getting enough.

But the type of magnesium matters. And citrate is not the one to take before bed.

Magnesium citrate’s claim to fame is that it’s highly bioavailable, meaning your body absorbs it well. But that also means it’s great at pulling water into your intestines and making things move. In small doses, sure, it might just help with minor constipation. In larger amounts? No.

And it’s not just citrate. Other forms of magnesium also come with a catch:

Magnesium hydroxide – You might recognize this one as the active ingredient in Milk of Magnesia. Helps with heartburn, but taking high dose can give you an unpleasant surprise if what you’re looking for a restful night.

Magnesium oxide – Marketed as a general supplement, but mostly just gives you diarrhea if you take too much.

Magnesium sulfate – The active ingredient in Epsom salt baths. Good for muscle relaxation when absorbed through your skin. Drinking it could result to same laxative nightmare.

Which Magnesium Actually Helps You Sleep?

If you’re going to take magnesium, take the right one, because the only thing worse than insomnia is being awake in the middle of your REM sleep.

Now that we’ve cleared out the bathroom bombs, there are magnesium types that may help you wind down such as:

Magnesium glycinate – The gold standard for sleep. It’s easy on the stomach, actually helps with relaxation and mild anxiety, and won’t make you sprint to the toilet at 3 a.m.

Magnesium L-threonate – This one can cross the blood-brain barrier, meaning it can improve cognitive function and sleep quality according to a 2022 study. According to recommendation, taking 1,000 milligrams (1 gram) of magnesium L-threonate daily for up to three weeks may improve sleep quality and daytime functioning, which is a nice bonus.

Magnesium taurate – Good for your heart and might have mild calming effects, but not as well-studied for sleep as glycinate or L-threonate.

Magnesium malate – More useful for muscle recovery and energy, so probably not your best bet for bedtime.

Additional Fix for Your Sleepless Nights

Magnesium can help, but it’s not a magic bullet. If you’re lying in bed wide awake and overthinking everything you’ve ever said, you probably need to fix your sleep hygiene first. No amount of magnesium (or melatonin, or overpriced supplements) is going to counteract doom-scrolling until 2 a.m. or binge-watching Netflix with the brightness cranked up.

If you want better sleep, start with the basics:

• Take out the phone an hour before bed – Blue light kills melatonin production. Your brain thinks it’s daytime. Stop tricking it.

• Make your room a cave – Blackout curtains. No LEDs blinking at you. Cold temperatures (your body sleeps better in a cool room).

• Set a real bedtime – You are not an immortal being. You cannot run on four hours of sleep and “catch up” later. Consistency is key.

• Don’t eat heavy meal before bed – Heavy meals and sugar can mess with sleep. Also, caffeine has a half-life of five to six hours—that 4pm coffee is still haunting you at midnight.

• Knowing what magnesium to take – If you are keen on supplementing, go for glycinate or L-threonate.