Magnesium Glycinate Vs Oxide Review [2020]

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Medically reviewed by, Russell Braun RPH

It is 10am you should be working near peak performance, but you just don’t have any energy. Even though you think you got a good nights sleep. The coffee helped in the morning but now you fell off the caffeine cliff. You wonder, is this just part of getting older? On the other hand, what if it was something as simple as a low magnesium level. Consequently, now your at the pharmacy and wondering, which is better magnesium glycinate vs oxide?

Believe it or not magnesium is all around us. Sources say it is the fourth most abundant element on earthy and in the top 10 in the solar system!

Why is magnesium important?

Magnesium is said to be involved in over 300 metabolic reactions that take place in your body. Thankfully it is abundant throughout our body because it is a crucial part of energy production. As a result, the list of things magnesium is involved in include:

Muscle contractionMuscle relaxationHormone processingHormone balance
Blood vessel relaxationReduces inflammationEnergy productionMetabolism of carbohydrates, fats and amino acids
Calcium absorptionBone developmentHealth of teethProtein creation
Control of blood sugarRegulate blood presssureNerve activationHeart rhythm

Given all the process it is involved in, makes it no surprise that magnesium would also be an effective treatment for certain health conditions. The evidence is clear supporting prevention and or treatment when magnesium levels are low for the following conditions:

  • Balances cortisol levels
  • Certain abnormal heart rhythms
  • Constipation
  • Depression
  • High blood pressure
  • Increase testosterone production
  • Improves thyroid function
  • Lowers blood sugar levels
  • Maintain normal estrogen levels
  • Metabolic syndrome
  • Migraine headaches
  • Muscle cramps
  • Polycystic ovarian syndrome
  • Preeclampsia
  • Premenstrual syndrome
  • Restless leg syndrome

Where do we get magnesium from?

Magnesium is found almost everywhere from sea water to the soil. Likewise, it is part of the chlorophyll in plants, which is the part that makes them green. Therefore, it is not surprising that a diet that includes plants and vegetables would contain good amounts of magnesium.

Unfortunately, most people eat too many processed foods and not enough fruits and vegetables. As a result magnesium levels are often low.

Could you be magnesium deficient?

It is estimated that in developed countries magnesium deficiency may be found in as many as 70-75% of the population. That certainly seems like a high number, what are the most common causes?

  • Magnesium is depleted from the soil used to grow our food today from excessive farming.
  • Processed foods (think anything that is prepackaged) has been exposed to processes that deplete the magnesium from them.
  • Too much stress, which raises cortisol levels in the body.
  • Excessive alcohol use.
  • Drinking too much coffee.
  • Medications such as acid reducers, birth control, antibiotics, laxatives, diuretics, vitamin D.
  • Use of aluminum cookware.
  • Being deficient in vitamin B6.

Symptoms of magnesium deficiency

The table below lists the most common symptoms of magnesium deficiency. However, keep in mind these symptoms could also be due to other causes.

Muscle crampsFrequent headachesNervousness
Twitching eyelidsMood changesCraving sweets
Low energyPMSTrouble sleeping

Therefore, testing your magnesium level is the best way to know for sure. A blood test is the most common method for measuring magnesium levels. This can be misleading though because magnesium is stored in every cell in the body. Consequently, if blood levels drop it will be pulled from cells to bring it back up.

As a result many doctors will check the level of magnesium in your red blood cells. If those levels are low then it is a sure sign of deficiency. You can order theses tests yourself if you don’t want to go to a doctors office. Companies now offer at home testing options or you can order labs online and go get blood drawn through companies such as Healthlabs.com.

Above all, don’t rush out and buy supplements without first reviewing a few basic non medication tips. You know the boring stuff that has a real impact!

Before magnesium supplements try simple lifestyle changes!

Eating right

First of all, our ancestors did not have food available to them in abundance like we do today. In other words, they would have to eat more plants in their diet, which contain magnesium. However, far to few in developed nations today get enough vegetables in their daily diet.

Remember magnesium is part of the chlorophyl or the green part of plants. Subsequently, green leafy vegetables are your best sources of magnesium. In addition, some other great sources are listed in the table below.

VegetablesSpinach, kale, avocado
NutsAlmonds, peanuts, cashews
Whole grainsOatmeal, wheat
LegumesBlack beans, black eyed peas, lima beans

Stress less

When you experience stress, your body reacts by releasing a hormone called cortisol. Certainly, this hormone is essential to help us deal with stress in the short term. However, people today stress over many more things than they should. This results in cortisol being released far more often than it should.

On the other hand, chronic cortisol exposure is very bad for your body for a number of reasons. One important one is it depletes your magnesium levels. As a result of long term high cortisol, more magnesium is lost in the urine. This is problematic because magnesium helps to control and stop cortisol release. Therefore, it can become a compounding effect.

There are several great ways that cost nothing, but have been proven to lower stress levels. They include:

  • Practice deep breathing
  • Learn meditation
  • Exercise
  • Be outside in nature
  • Seek stress counseling

If you want to take this one step further the book Innercise by John Assaraf is a great resource to learn all about dealing with stress.


Alcohol use can certainly lead to magnesium deficiency. The more you drink alcohol the more likely your magnesium will be lost in the urine. Alcohol acts as a diuretic and magnesium is lost by the kidneys when more urine is produced.

Consequently, cutting back on alcohol consumption can prevent this loss of magnesium.

Which type of magnesium is best?

What can you do after you try lifestyle changes and get tested only to find you still have a low magnesium level? In that case the next step would be find a magnesium supplement.

How to know which one to choose?

It can be confusing because of all the different types of magnesium you will find on the market. Are they all the same? First, let’s take a quick look at what the different hard to pronounce words after magnesium actually mean.


The different forms of magnesium are simply different salts. For example, think back to chemistry class. A positive ion and a negative ion get together to form a salt because they are not stable existing by themselves. In other words salt simply means the combination of an acid and a base.

Magnesium glycinate and magnesium oxide are simply different salt forms of magnesium. In glycinate magnesium is bonded to glycine and in oxide magnesium is bonded to oxygen.

Magnesium Glycinate

Glycine is an amino acid, which is much larger in size than magnesium. The two components are bonded together in a process called chelation to make magnesium glycinate. Moreover, chelation is simply the process of bonding molecules with metals. In this case glycine is the molecule and magnesium is the metal.

There are a few advantages to combining magnesium with glycine, which include:

  • It helps keep the pH, a measure of the acid to base ratio in balance. This helps magnesium to be absorbed from the GI tract.
  • It prevents magnesium from binding with phosphorus in the stomach. This can hinder absorption of the magnesium especially if it is taken close to a meal.
  • Glycine is an amino acid and a neurotransmitter. It works to help relax muscles and enhance sleep.
  • NMDA receptors also respond to glycine. This interaction is is thought to have a positive effect on thinking and mood when triggered.

One of the keys to magnesium supplements is how much get absorbed. Any magnesium that is not absorbed it going to have a laxative effect. Many magnesium products are sold for this use. However, if you want something to help raise your magnesium levels in the body these forms are not ideal.

The combination of magnesium and glycine could be expected to have positive effects on diseases listed above. Click here to see more on health effects of glycine. Once the medication is absorbed, they are split apart and can be expected to individually have positive effects.

Magnesium glycinate products

There are numerous products on the market that contain magnesium glycinate. How can you know which brand is the best?

One problem with magnesium is it is sold as nutritional supplement. This classification of drugs does not require safety and efficacy testing by the Food and Drug Administration (FDA). Both prescription and Over The Counter (OTC) medications are required to follow these FDA guidelines.

Unfortunately nutritional supplements have created a whole category of products that may not adhere to good manufacturing practices. So, what can a consumer do? Make sure you buy products verified by the United Staes Pharmacopeia (USP). This is the known trusted source for ensuring you are buying quality products.

The BestRxforSavings recommendation is to always use USP verified products whenever possible.

The only USP verified product that makes magnesium glycinate is Nature Made.

Nature Made High Absorption Magnesium Glycinate 200 mg Capsules for Muscle Relaxation 180 Count200mg Magnesium glycinate per capsule

Directions for use are to take two capsules daily. It is also recommended to take magnesium glycinate with food or water.

Magnesium glycinate pros:

  • A large amount of the magnesium is able to be absorbed.
  • When bound with glycine is causes much less laxative effect than other forms of magnesium.
  • Because so much magnesium is absorbed, many of the magnesium benefits are seen.
  • Glycine has also been shown to promote stress relief and clam anxiety.
  • Moreover, circadian rhythm and sleep are improved by glycine.

Magnesium glycinate cons:

  • The glycinate form of magnesium has been reported to have a bad taste.
  • It often takes large pills or multiple ones to get the required dose of magnesium.
  • The cost of chelated magnesium products like glycinate are normally higher than other types.

Magnesium glycinate cost:

  • One bottle of Nature Made magnesium glycinate contains 180 capsules and costs $31.75.**
  • If you take two capsules per day that is a 90 day supply, which brings the monthly cost to ~$10.

All in all this is a relatively affordable supplement given the potential upside.

**Prices subject to change.

Magnesium oxide

Oxygen is combined with magnesium to make magnesium oxide. This form of magnesium is much smaller in size overall than magnesium glycinate. In addition, it has a high percentage of magnesium per the weight, meaning pills don’t have to be so big.

Magnesium oxide is commonly used as an antacid to treat heartburn and indestion symptoms. It is also used to relieve constipation. Finally, it can be used to increase magnesium levels throughout the body.

The oxide form chemically attracts water molecules in the stomach and intestines. This results in pulling water into the stool and thus the reason it is used for constipation. However, some people will not be able to tolerate this as it can also cause diarrhea.

Magnesium oxide products

Again, Nature Made is the only USP verified manufacturer of magnesium oxide.

Nature Made Extra Strength Magnesium Oxide 400 mg Softgels, 110 Count for Nutrition Support (Packaging May Vary)400mg Magnesium oxide per softgel

The directions are to take 1 softgel capsule daily. Take the softgel with a meal for best results.

Magneium oxide pros:

  • Effective for indigestion and heartburn.
  • Can be a good choice to raise magnesium levels especially with constipation.
  • Good choice if you do not want to take multiple capsules.
  • Very cost effective option.

Magnesium oxide cons:

  • Some people may experience diarrhea especially if not constipated.
  • Can cause a metallic taste that is unpleasant, especially if taken daily.
  • If you touch your eyes or nose after touching the capsules they can become irritated.

Magnesium oxide cost:

The NatureMade bottle with 110 softgel capsules costs $6.19** Since you only take 1 per day that lasts 110 days and thus the cost per month is about $1.75. Obviously this seems like a good deal especially if you have magnesium deficiency.

**Prices subject to change.

Magnesium Glycinate Vs Oxide: The Similarities

Both of these forms of magnesium provide a 400mg dose. They are both used to provide magnesium supplementation and prevent deficiency. NatureMade a reputable manufacturer verified by USP produces both forms of magnesium.

Once either form of magnesium is absorbed in the body the compounds break down, leaving the same magnesium element to be used by the body.

Magnesium Glycinate Vs Oxide: The Differences

Glycine is an amino acid and much larger component to be combined with magnesium. Therefore, it takes multiple, larger tablets to get the same 400mg dose as with oxide. Oxygen is a smaller molecule to combine with magnesium. However, it is attracted to water and this causes less magnesium to be absorbed than with glycine. Finally, the smaller amount of magnesium oxide being absorbed leads to more water in the GI tract and the potential for diarrhea.

Magnesium Glycinate vs Oxide FAQs

Should you take magnesium everyday?

According to the National Institutes of Health (NIH), office of dietary supplements magnesium requirements depend on age and sex. Adult women and men require 320mg and 400mg per day respectively. While most people get some of this from their diet, many don’t get enough. Therefore, many people could benefit from taking magnesium daily.

If you have any of the following, then taking magnesium daily should be discussed with your doctor or pharmacist.

  • Heart disease
  • High blood pressure
  • Type II diabetes
  • Migraine headache
  • Osteoporosis

What is the difference between magnesium and magnesium oxide?

Magnesium by itself would not be stable long enough to make a supplement. Therefore, magnesium must be combined with anions to make a salt. These salts are stable so that they can be made into capsules for use.

When magnesium is combined with oxygen, it creates magnesium oxide. Therefore, the only difference is that magnesium oxide is a stable salt form of magnesium.

Is magnesium oxide the best form of magnesium?

Magnesium oxide is a low cost way to supplement magnesium in your diet. The amount of magnesium that is absorbed is not much as some other forms. However, if you suffer from indigestion, heart burn or frequent constipation then absorption is not a concern. In these cases magnesium works its magic in the GI tract. For those cases, magnesium oxide may be the best option for you.

Why is magnesium glycinate better?

When magnesium is chelated with glycine, it allows for better absorption. If you need to raise magnesium levels in the body then this does prove to be a better option than ones that are poorly absorbed.

There are also forms of magnesium that are chelated with other amino acids. Click here for more information on some of those options. In addition to the benefits of magnesium you also get benefits from what those amino acids can do.

What is the best time to take magnesium glycinate?

Because glycine works on NMDA receptors it has been shown to have calming effects. These include helping with circadian rhythm and sleep. Therefore, taking magnesium glycinate within two hours of bedtime is typically a best practice.

What are the side effects of magnesium supplements?

Magnesium is largely safe to use and the risk of side effects are low. That is part of the reason why it is so widely available as a dietary supplement. Side effects can occur, but typically only once you get over the recommended doses of 320mg to 400mg for women and men respectively.

Those side effects could include:

  • Nausea
  • Vomiting
  • Diarrhea
  • Stomach upset

Higher doses could lead to magnesium toxicity which can be serious. Make sure to talk to your doctor before starting any magnesium products to ensure your kidney function doesn’t put you at risk for effects such as:

  • Confusion
  • Irregular heartbeat
  • Low blood pressure
  • Coma

Does magnesium make you gain weight?

Magnesium has not been shown to cause weight gain. Rather, magnesium deficiency is thought to put you at risk for weight gain. That does not mean that taking large doses of magnesium will cause weight loss either. Instead remember many of the 300 chemical reactions in the body that magnesium is involved deal with energy use and production. Keeping magnesium levels in the normal range can even out the way the body uses energy, part of which is burning fat and carbohydrates.

In Conclusion

Magnesium glycinate and magnesium oxide are both good options for supplementing the mineral. Deciding which one is for your will depend on your desired outcome. Keep in mind that the cost of glycinate are higher than oxide.

Click here to get Dr. Jason Reed’s exclusive list of medication questions you MUST ask your doctor, for FREE!

Share your story

Have you used magnesium glycinate or magnesium oxide? Also, please share how they worked for you. Chime in below with your comments and thoughts.

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