What time of day should you take magnesium? It depends – here’s what to know

Expert review by Ashley Jordan Ferira, Ph.D., RDN

While some supplements should be taken at specific times of the day, others are free to be consumed whenever is most convenient for you. Wondering where magnesium—one of the most popular supplements in the U.S.—falls on the spectrum? Here’s what to know about when to take different types of magnesium to reap the most benefits (and stomach the fewest side effects)

The best time of day to take different types of magnesium supplements.

For a quick recap on why you might want to take a magnesium supplement in the first place, hundreds of processes in the body require the almighty mineral. While certain foods contain magnesium, your daily needs are quite high (310 to 420 milligrams daily), and an estimated 43% of U.S. adults currently fail to meet their daily needs through diet alone. Supplementing with magnesium is a way to proactively mind that gap, plus support brain health, heart health, muscle and skeletal health, blood sugar balance, and much more, on a daily basis.*

As for the best time of day to consume the mineral, it largely depends on the type of magnesium you’re taking. There are a handful of forms, or complexes, of magnesium supplements that pair the mineral with different compounds to assist with its delivery.

Today, we’re talking through the timing of four of the most popular forms. While you should always follow the timing instructions provided on your particular supplement (or by your doctor), these are good general best practices to keep in mind.

Magnesium glycinate: Bedtime.

Magnesium glycinate (or more accurately, bisglycinate) pairs magnesium with two molecules of glycine—an amino acid that supports protein status in the body, but has also been found to promote relaxation and improve sleep quality in clinical trials.*

The combination of magnesium and glycine is highly bioavailable, meaning it’s easy for the body to absorb and you shouldn’t need to take it with a meal. Unlike other types of magnesium supplements that are less absorbable and can, let’s say, stimulate the bowels, taking magnesium glycinate should not send you to the bathroom. All things considered, this is a supplement that is best taken at bedtime when you’re looking to wind down from the day and prepare for a night of deep, uninterrupted sleep.* The exact timing will vary based on the supplement, but we recommend taking mbg’s sleep support+ supplement, formulated with 120 milligrams of magnesium bisglycinate and other sleep enhancers jujube and PharmaGABA® in each serving, one to two hours before bed.*

Magnesium citrate: Earlier in the day, with a meal.

Another popular type of magnesium supplement, magnesium citrate also tends to be pretty easy for the body to absorb (though not as easy or gentle as magnesium bisglycinate). It pairs magnesium with citric acid to assist with absorption. This supplement is most often taken to address low levels of magnesium in the body, although technically all magnesium complexes that effectively deliver the mineral to your body are helping bump up your magnesium status.

However, magnesium citrate does have a natural laxative effect in higher doses, so it can also help get things moving down there. Unlike glycinate, you probably won’t want to take this one right before settling in for the night as it could wake you up to use the restroom. Instead, taking magnesium citrate earlier in the day with some food, around breakfast or lunchtime, will help ensure it’s properly and pleasantly absorbed.

Magnesium oxide: Earlier in the day, with a meal.

Magnesium oxide—magnesium and oxygen ions—is one of the less bioavailable forms of the mineral. This simple and affordable pairing is often used to fulfill magnesium needs and encourage bowel movements, getting things moving in the gut. To assist with absorbability and avoid possible stomach discomfort, it should always be taken with a meal. Taking magnesium oxide earlier in the day is also a prudent move, as again, those bathroom trips might interrupt your wind-down routine or slumber.

Magnesium malate: In the morning.

Finally, this supplement pairs magnesium with malic acid—which has been shown to promote energy production in some studies. For this reason, most people will want to take this supplement in the morning hours or at the start of their day. (It’s a popular supplement to take before a.m. workouts.) While it is more bioavailable than magnesium oxide, it should still be taken with some food to minimize the chance of uncomfortable side effects.

Whatever way you time your magnesium supplement, taking a daily supplement at roughly the same time will help you get into a rhythm and ensure you don’t skip a day.

The takeaway.

The best time to take magnesium ranges from in the morning to right before bed, depending on what the mineral is paired with. The quality of the supplement can also have a big impact on its absorbability and efficacy, so scan through our list of the 16 highest-quality options on the market here.

If you are pregnant, breastfeeding, or taking medications, consult with your doctor before starting a supplement routine. It is always optimal to consult with a health care provider when considering what supplements are right for you.