Magnesium is an essential mineral that plays a crucial role in many bodily functions, including muscle and nerve function, heart rhythm regulation, and bone health. While this electrolyte can be obtained through a healthy diet, research shows that many people eating modern-day, processed diets don’t get enough. (After all, magnesium is found in unprocessed foods like vegetables, legumes, nuts, seeds, and whole grains.) High alcohol intake, eating over-cooked foods, and certain health conditions can also contribute to low magnesium levels.
In fact, nearly half of U.S. adults aren’t getting adequate magnesium from their diets alone. That’s a pretty big deal when you consider how much your body relies on this mineral every single day—from helping you fall asleep at night to keeping your heartbeat steady.
If you’re in need of more magnesium, supplements may be incredibly helpful. However, the tricky thing about choosing a magnesium supplement is that so many types are available. Magnesium oxide, magnesium citrate, magnesium glycinate—it’s enough to make your head spin.
Each type of magnesium affects us a bit differently. While some forms are most helpful for easing aches and helping us sleep, others really pack a punch for our digestive system. Use this guide to figure out which of the different types of magnesium supplements makes the most sense for your individual needs, plus when to take it for best results.
The Benefits of Magnesium
Experts believe that magnesium deficiencies are somewhat common among adults, especially those with digestive, cardiovascular, and metabolic issues. Our bodies need a steady supply of magnesium to function optimally, starting with our diet. Foods like leafy greens, chia seeds, milk, whole grains like oats, legumes, pumpkin seeds, and avocados are great sources.
The thing is, even when we’re eating well, modern farming practices and food processing can reduce the magnesium content in our food. Plus, stress, certain medications, and even intense exercise can deplete our magnesium stores faster than we can replenish them through diet alone.
Potential benefits of consuming enough magnesium:
- Support for bone health: Magnesium is necessary for proper bone formation and maintenance of bone density, and low levels of magnesium have been linked to a higher risk of osteoporosis. Think of it as calcium’s partner in keeping your bones strong—you need both working together.
- Cardiovascular support: Magnesium helps regulate heart rhythm and blood pressure. It’s like a natural rhythm keeper for your heart, helping it beat steadily and maintain healthy circulation.
- Assistance with mood and sleep: Many people find that magnesium has a calming effect on the body and may help improve their mood and reduce symptoms of anxiety and tension. Additionally, magnesium is important for the production of melatonin, a hormone that regulates sleep. If you’ve ever noticed you sleep better after a magnesium-rich meal, this is why.
- Relief from migraines: Some research suggests that magnesium may help ward off migraines. People who experience frequent headaches often have lower magnesium levels, and supplementing might help reduce the frequency and intensity of those painful episodes.
- Help with exercise performance: Because it’s crucial for muscle function and energy production, low levels of magnesium can lead to muscle weakness and fatigue, hindering physical performance and recovery. That post-workout muscle soreness? Magnesium can help with that, too.
Who Should Supplement With Magnesium?
The recommended daily intake of magnesium depends on age, sex, and other factors, such as whether a woman is pregnant or breastfeeding. The National Institutes of Health currently suggests that adult men need up to 420 milligrams of magnesium per day, adult women need up to 320 milligrams, and pregnant and breastfeeding women need up to 400 milligrams per day. However, some experts believe that these recommended amounts may be too low for certain people.
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Generally, if you suspect you’re falling short on magnesium, clinical nutritionist Rebecca Fallihee, M.S., C.N.S., L.D.N., recommends starting with incorporating more magnesium-rich foods into your daily eats. That said, people who have trouble with nutrient absorption, athletes, and those that are under a lot of stress usually require more magnesium, in which case incorporating supplements is a smart move.
Here’s the thing: Your lifestyle matters when it comes to magnesium needs. If you’re training for a marathon or hitting the gym hard five days a week, you’re probably using up magnesium faster than someone with a desk job. Same goes if you’re dealing with chronic stress—your body burns through magnesium when it’s in fight-or-flight mode.
Some signs that you’re not getting the magnesium you need include:
- Muscle cramps or restlessness (especially those annoying Charlie horses that wake you up at night)
- Trouble sleeping or staying asleep
- Fatigue that doesn’t seem to go away, even with rest
- Chronic stress or feeling constantly on edge
- Constipation or irregular bowel movements
- Tingling or numbness in your hands or feet
If you’re not sure where you stand on this vital mineral—and how to best proceed in upping your intake—consider checking in with a credentialed nutritionist to take stock of your diet and lifestyle. Sometimes an outside perspective can help you spot patterns you’re missing.
The Best Time Of Day To Take Magnesium
Should you decide to add a magnesium supplement to your routine, when you should take it depends on the type of magnesium you’re using (which itself depends on why you want to take a supplement in the first place), says dietitian Emily Fultz, M.S., R.D.N.
What makes magnesium unique is that timing really does matter—probably more than with most other supplements you might take. That’s because different forms of magnesium work in different ways and on different timelines in your body.
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Regardless of the type (and at what time of day), always take your magnesium supplement with a meal to help prevent any potential laxative effects, unless that’s the intended result. You’ll also want to avoid taking magnesium with high amounts of zinc, which can interfere with its absorption.
Why Food Timing Matters
Taking magnesium with food isn’t just about preventing stomach upset—it’s about helping your body actually use the supplement effectively. When you take magnesium on an empty stomach, some forms can draw water into your intestines pretty quickly, which might lead to that bathroom urgency we mentioned. A meal slows down that process and gives your body time to absorb the magnesium properly.
Types Of Magnesium You Can Take Anytime
You can generally take the following forms of magnesium at any time of day, depending on why you’re supplementing.
Magnesium Citrate
This type of magnesium can have a mild laxative effect and is often used to support digestion in those who experience irregularity. Though you can take magnesium citrate anytime, consider testing it out when you have easy access to a bathroom, just in case your stomach reacts strongly.
Here’s what that looks like in real life: If you’re trying magnesium citrate for the first time, maybe don’t take it right before a long meeting or a road trip. Start on a weekend morning when you’re home and can gauge how your body responds. Most people find it produces results anywhere from 30 minutes to 6 hours after taking it, which is quite a range.
Magnesium citrate is about 25-30% bioavailable, meaning your body can actually use about a quarter to a third of what you take. That makes it one of the better-absorbed forms, which is why it’s so popular for both digestive support and general magnesium supplementation.
Magnesium Oxide
This type of magnesium is commonly found in over-the-counter antacid medications and may be used to relieve symptoms of heartburn or indigestion. Because it’s less bioavailable than other types of magnesium, it’s the most likely to send you running to the toilet, which can be a good thing if you’re having trouble going! Take it any time of day with food, Fultz suggests. And maybe consider trying it out at home versus at the office or out and about.
The reason magnesium oxide has such strong laxative effects is actually because your body absorbs less than 4% of it. The rest stays in your intestines and draws in water, which is exactly what creates that bowel-moving effect. So while it’s not great for boosting your overall magnesium levels, it can be helpful for occasional constipation relief.
The Best Types Of Magnesium To Take In The Morning
The following types of magnesium supplements are best taken in the morning or earlier in the daytime.
Magnesium L-Threonate
This form of magnesium has been shown to support immune function and may also be useful for enhancing cognitive and bone health. Researchers believe magnesium l-threonate has these effects because it supports metabolic pathways in the body, including energy generation in cells and protein production. Although there isn’t much research available on timing with this particular form of magnesium, you might consider taking it in the morning given its benefits for cognition.
Here’s why the morning timing makes sense: Magnesium L-threonate is unique because it can actually cross the blood-brain barrier—basically, it can get into your brain tissue where other forms can’t. This makes it particularly helpful for memory, focus, and mental clarity throughout your day.
Some people find splitting their dose works even better—taking half in the morning for daytime cognitive support and half in the evening to support memory consolidation during sleep. It’s one of those supplements where you might need to experiment a bit to find what works best for your schedule and goals.
Magnesium Malate
It may be a bit harder to find this type of magnesium compared to the others, but magnesium malate can potentially help promote energy production, according to Fultz. For that reason, she recommends taking it earlier in the day.
The “malate” part comes from malic acid, which your body uses in the process of converting food into energy. Think of it like adding an extra boost to your cellular batteries. That’s why athletes and people dealing with chronic fatigue often find this form particularly helpful when taken in the morning or early afternoon—it supports your natural energy production without the jitters or crash you might get from caffeine.
If you’re someone who tends to hit an afternoon slump, magnesium malate taken with breakfast or lunch might help you power through without reaching for that third cup of coffee.
The Best Types Of Magnesium To Take At Night
On the flipside, the following magnesium supplements are ideally taken in the evening.
Magnesium Glycinate
Magnesium glycinate is known for its calming effects and is often used to promote relaxation and better sleep, says Fultz. It’s best taken at night before bed. “It’s a highly bioavailable form of magnesium (easy to absorb), so you do not need to take it with a meal or worry about running to the bathroom afterward,” she adds. Because it’s more bioavailable, magnesium glycinate is a good option for those who have low levels and want to boost them, Fallihee notes.
The “glycinate” part refers to glycine, an amino acid that has its own calming properties. When magnesium and glycine team up, they create a one-two punch for relaxation. Glycine helps activate calming receptors in your brain, while magnesium helps regulate your nervous system and supports melatonin production.
Here’s a practical tip: Take your magnesium glycinate about 1-2 hours before you actually want to fall asleep. So if your target bedtime is 10 PM, take it around 8 or 8:30 PM. This gives it time to start working so you can feel that gentle calming effect as you’re winding down for the night.
Many people make magnesium glycinate part of their evening ritual—taking it while reading, during a skincare routine, or while having a cup of herbal tea. Creating that consistent habit not only helps you remember to take it, but also signals to your brain that it’s time to start relaxing.
Magnesium Chloride
Magnesium chloride is commonly used in topical applications, such as magnesium oil or bath salts, to raise magnesium levels and improve electrolyte status. Technically, magnesium can be used topically any time of day (like other forms), but most people prefer using it in baths at night to unwind and help them sleep.
There’s something really soothing about a warm bath with magnesium salts after a long day. The magnesium can absorb through your skin (though it’s slower than oral supplementation), and the warm water helps relax tense muscles. Some people spray magnesium oil directly onto sore muscles before bed, which can help with both magnesium absorption and muscle recovery overnight.
Just a heads up: Magnesium oil can feel a bit tingly or itchy on your skin at first—that’s normal and usually goes away after a few minutes or with regular use. If it bothers you, dilute it with a little water or apply lotion over it.
Supplement Considerations To Keep In Mind
The NIH suggests that adults supplement with no more than 350 milligrams of magnesium per day, as higher doses can cause gastrointestinal side effects. However, some individuals may require higher amounts, in which case they should supplement under the guidance of a healthcare professional.
It’s worth noting that this 350mg limit applies to supplemental magnesium only—it doesn’t include the magnesium you get from food. So if you’re eating a magnesium-rich diet (which you should be!), you don’t need to count those food sources toward the limit.
To prevent side effects and find your ideal amount when supplementing with magnesium, start with a low dose and gradually increase as needed while monitoring for any adverse effects.
Working with Your Medications
One important thing to keep in mind: Magnesium can interact with certain medications, including antibiotics, blood pressure medications, and bisphosphonates (used for bone health). If you’re taking any prescription medications, make sure to space your magnesium at least 2 hours before or after taking them. This gives each substance time to be absorbed without competing with the other.
When in doubt, talk to your pharmacist—they’re a great resource for understanding supplement-medication interactions and can help you figure out the best timing strategy for your specific situation.
Side Effects to Look Out For
While magnesium is generally safe and well-tolerated, high doses of magnesium supplements can cause side effects in some individuals, most commonly diarrhea. According to the NIH, other potential side effects of magnesium supplements can include lower blood pressure (which can manifest as lightheadedness or dizziness) and interference with the absorption of certain medications, particularly antibiotics and blood pressure drugs. If any of these areas are of concern for you, check in with a health professional before supplementing.
The good news is that most side effects are dose-dependent, meaning they happen when you take too much. If you experience digestive upset, you can usually fix it by reducing your dose or switching to a different form of magnesium. For example, if magnesium citrate is too much for your digestive system, switching to magnesium glycinate might solve the problem since it’s gentler on the stomach.
Also, remember that it can take a few weeks of consistent use to see the full benefits of magnesium supplementation. Don’t get discouraged if you don’t notice dramatic changes after just a few days. Give your body time to restore its magnesium levels, and pay attention to subtle improvements in sleep quality, muscle recovery, stress levels, or whatever your primary goal is.
The bottom line? Matching the right type of magnesium to the right time of day—and to your specific health goals—can make all the difference in how effective your supplement routine actually is. Start with one form that addresses your biggest concern, stick with a consistent timing schedule, and give it at least a month to see how it works for you. Your body will thank you for the extra support.