Why Taking Magnesium Citrate Before Going To Sleep Is A Huge Mistake

If you're on TikTok, you've probably heard of the Sleepy Girl Mocktail to help you sleep. The concoction consists of tart cherry juice, magnesium, and a sparkling soda like Poppi, and many TikTok users have become instant fans (we tried it but weren't impressed). On the surface, it sounds logical. Tart cherry juice has a small amount of melatonin so it might help regulate your sleep-wake cycle, and magnesium can help calm your muscles and nervous system to help you sleep.

Whether you drink a Sleepy Girl Mocktail or simply take a magnesium supplement, know that there are different types of magnesium. While magnesium glycinate and magnesium L-threonate may improve sleep quality, taking magnesium citrate before bed can disrupt your sleep.

Why? Magnesium citrate is a powerful laxative. If you've had a colonoscopy, you've probably had to take magnesium citrate to help clean out your intestines. Rather than helping you sleep better, magnesium citrate could have you spending most of your night on the toilet. It's important to know that different forms of magnesium can have different effects on your body.

Magnesium supplements that could cause digestive issues

Magnesium is an important mineral that participates in more than 300 functions in the body, including regulating your blood pressure and glucose, synthesizing proteins, and transporting electrolytes across your cells. Your body stores some magnesium in your bones and tissues, but you also need to take in more magnesium through food. Adult men need 420 milligrams of magnesium, and women need 320 milligrams.

(Here are some side effects of taking too much magnesium.)

You can buy magnesium supplements in many forms, but be careful about what claims are made on the label or in promotional videos. Magnesium citrate is commonly sold as a generic magnesium supplement, and it's promoted to be better absorbed by the body. It can also help alleviate any magnesium deficiencies. Just remember that larger amounts could cause you to poop in as little as 30 minutes.

You can often find magnesium hydroxide among medications for heartburn. Magnesium hydroxide comes in chewable tablets or liquid form (think Milk of Magnesia), but it also can cause you to poop. If you take magnesium hydroxide before bed for an upset stomach or indigestion, you can be sure you'll have a good bowel movement the next day. Magnesium oxide also has laxative effects, but it can also be used as an antacid.

Magnesium types that can help you sleep

Some types of magnesium are added to sleep formulas or sold separately as sleep supplements. Magnesium glycinate is easily absorbed by your body without the anxiety of making a bathroom run in the middle of your REM sleep. If you know you don't get enough magnesium in your diet, supplementing with magnesium glycinate could also alleviate mild anxiety, according to a 2017 article in Nutrients.

A newer form of magnesium is magnesium L-threonate, which can cross the blood-brain barrier. A 2022 study in Nutrients found that a supplement that included magnesium L-threonate improved cognition and memory in older adults. Taking 1,000 milligrams (1 gram) of magnesium L-threonate daily for three weeks also improved sleep quality and daytime functioning, according to a 2024 study in Sleep Medicine: X. However, you could experience side effects such as stomach upset or diarrhea.

Another type of magnesium that can have a calming effect is magnesium sulfate, the form of magnesium found in Epsom salts. A hot bath can be a great addition to your bedtime routine, and adding Epsom salts can soothe your tired muscles and promote relaxation. Not only that, but you'll be absorbing this form of magnesium through your skin without the digestive side effects. However, be aware that Epsom salts taken internally has a laxative effect so you don't want to drink or eat it if you're looking to get a good night's sleep.