How Long Does It Take for Magnesium Supplements to Work?

  • By Rebecca Kesner
  • 9 minute read
White tablets on a pink background around the periodic symbol for magnesium Mg. How long does it take for magnesium supplements to work?

Magnesium is one of the seven essential minerals that we need to function optimally, alongside calcium, phosphorus, sodium, potassium, chloride, and sulfur.

Notably, magnesium stands as the fourth most abundant mineral in our body, underlying its critical importance to our overall health and bodily functions.

While we can get the majority of our recommended magnesium intake through diet alone, only about 30-40% of dietary magnesium is absorbed by the body. (1)

This means that magnesium deficiency can be fairly common, thus the importance of knowing how to take it as a supplement would be beneficial for anyone.

Magnesium supplements come in many forms, such as tablets, sprays, and lotions. Though, when topping up your magnesium intake through supplementation, it's important to do this in the correct way, which allows for optimum absorption.

This short guide details everything you need to know about supplementing with magnesium, what to expect, and how long does it take for magnesium to work?

What is Magnesium?

Scoop of magnesium next to a glass and bread slices

Magnesium is an essential mineral that is vital to our body's function. Some of the main roles of magnesium include:

  • Regulation of muscle function and nerve function
  • Regulation of blood pressure and blood sugar levels
  • Creation of protein and DNA
  • Absorption of key nutrients, such as vitamin D

Magnesium in Food

Leafy Greens

A bowl of leafy green spinach and kale

Leafy greens like spinach and kale are excellent sources of magnesium, essential for muscle and nerve function. Including these vegetables in your diet can significantly contribute to your daily magnesium intake.

Nuts and Seeds

A grid arrangement of different nuts

Nuts and seeds, particularly almonds, cashews, and pumpkin seeds, are not only rich in healthy fats and protein but are also high in magnesium. Snacking on these can help maintain adequate magnesium levels.


Beans, including black beans and kidney beans, offer a substantial amount of magnesium. They are a versatile dietary addition that can enhance your magnesium intake while also providing fiber and protein.


Hessian sacks of black beans, kidney beans and chickpeas with assorted pulses

Wholegrain foods such as quinoa, brown rice, and whole wheat bread are important sources of magnesium. Integrating wholegrains into meals is an effective way to ensure you're meeting your magnesium needs.

While most of our magnesium intake comes from a balanced, varied diet, supplementing with magnesium can sometimes be beneficial to bridge any potential nutrient gaps.

Supplementing with Magnesium: The Benefits and Uses

Colorful pills against a pink background depicting the various forms of 'magnesium supplementation

Supplementing with magnesium is also thought to provide additional benefits, such as:

  • Relieving muscle tension
  • Reducing tiredness and fatigue
  • Improving sleep quality
  • Aiding muscle recovery after exercise
  • Strengthening bones

This is why you may often find transdermal forms of magnesium supplements, such as sprays and lotions. Applying magnesium topically does not contribute to your overall daily intake, though it can be beneficial to apply it directly to problem areas and sore muscles.

Though, the most popular form of taking magnesium is as a tablet!

Different Types of Magnesium and Their Specific Benefits

When it comes to taking magnesium supplements, they come in various forms. Each with its unique characteristics and health benefits. Understanding the differences between these types can help you choose the most suitable form for your specific health needs. Below, we delve deeper into the various forms of magnesium supplementation, focusing on their bioavailability, specific health benefits, and recommended uses.

Magnesium Citrate

Magnesium Citrate

Magnesium citrate is highly appreciated for its bioavailability, meaning it's easily absorbed by the body compared to other forms. This type of magnesium is often recommended by a healthcare provider for those looking to improve digestion and relieve occasional constipation, thanks to its gentle laxative effect. Besides aiding your digestive system, magnesium citrate can also help muscle function by reducing cramps and improving overall magnesium levels in individuals with a deficiency. Its efficiency in absorption makes it a popular choice for those seeking quick and effective results.

Magnesium Glycinate

Bound to glycine, a calming amino acid, magnesium glycinate is easily absorbed with minimal risk of causing gastrointestinal distress. This form is particularly beneficial for individuals looking to enhance their sleep quality and reduce anxiety. Magnesium glycinate's calming effects on the brain and the central nervous system make it an excellent supplement for those seeking relief from stress and insomnia, without the laxative effect associated with other forms of magnesium.

Magnesium Oxide

Magnesium oxide is widely used for its laxative properties and its ability to treat migraines. (2) Although it has a lower bioavailability compared to other forms, it's effective in providing relief from constipation and is often prescribed for short-term use in bowel preparation for medical procedures. Its utility in managing migraine headaches makes it a dual-purpose supplement, offering significant relief for sufferers. Despite its benefits, due to its lower absorption rate, magnesium oxide might not be the best choice for addressing magnesium deficiency.

Magnesium Chloride

Magnesium Chloride

Magnesium chloride, a type of magnesium salt is noted for its excellent absorption rate. Magnesium chloride can be utilized both orally and topically. It is particularly suitable for those aiming to improve skin health and aid in detoxification. The topical application of magnesium chloride, in forms such as lotions and oils, is beneficial for addressing localized muscle soreness and improving skin hydration. Additionally, its use in oral supplementation can contribute to overall magnesium levels, making it a versatile choice for various health needs.

Magnesium L-Threonate

Magnesium L-threonate is distinguished by its ability to cross the blood-brain barrier, a unique characteristic that allows it to directly influence cognitive functions and memory enhancement. This form of magnesium is particularly beneficial for individuals looking to support brain health, improve memory, and potentially slow down cognitive decline associated with aging. Its targeted action on the brain makes magnesium L-threonate an ideal choice for those focused on cognitive health and neurological well-being. (3)

Magnesium Taurate

The combination of magnesium with taurine, an amino acid known for its cardiovascular benefits, (4) makes magnesium taurate especially beneficial for heart health and blood sugar regulation. This form of magnesium is often recommended for individuals with cardiovascular concerns, as it can help regulate heart rhythm, support healthy blood pressure levels, and enhance overall cardiovascular function. Additionally, its role in blood sugar regulation makes it a valuable supplement for those managing diabetes or at risk of developing the condition.

How Long Does It Take Magnesium Supplements to Work

An old fashioned round faced alarm clock surrounded by supplement bottles on a pink background. Depicts asking the question how long does it take magnesium to work?

How quickly magnesium works largely depends on the type of magnesium you are taking. With tablets, you may notice improvements after a week of consistent supplementation.

With transdermal forms, it spears to work instantly due to the quick absorption through the skin, which bypasses the digestive system.

Magnesium can clear and excrete through your body fairly quickly, usually within 24 hours, which is why deficiency is common. This means that to achieve an optimal magnesium intake, it should be taken consistently and regularly to ensure your levels are kept topped up.

Magnesium Deficiency

As dietary magnesium is not always efficiently absorbed by the body, deficiencies can be somewhat common. With between 2-15% of Americans experiencing a deficiency, (5) and some ICU patients experiencing a severe deficiency in this essential mineral. Having low magnesium levels may result in the following symptoms:

  • Difficulty sleeping
  • Feeling more tired and fatigued
  • Heart palpitations
  • Poor muscle function
  • High blood pressure
  • Constipation
  • Regular muscle cramps

It's important to get your magnesium levels checked by your doctor or healthcare provider if you suspect a deficiency or try supplementing with tablets if you feel you're falling short.

Man counting pills in hand

Magnesium Dosage

The daily recommended intake of magnesium is between 200-420mg per day, though specific doses depend on the brand of supplement you are taking. Doses also depend on your age and gender, as well as your general health status.

Though, this does not apply to transdermal magnesium supplements, which have different dosage recommendations due to the nature of the application.

Magnesium Side Effects

Many of the side effects that can be experienced when taking magnesium tablets are largely down to taking them on an empty stomach.

Magnesium is renowned for causing gastrointestinal issues, so it is key to take them alongside a meal to avoid any stomach upset.

Additionally, like with many other supplements, taking high doses of magnesium can also cause possible side effects such as:

  • Nausea
  • Neurological impairment
  • Headache
  • Flushing
  • Diarrhoea
  • Irregular heartbeat

Taking high doses of any supplement is never a good idea. A high dose never equals better results, so it's vital to stick to the recommended dose to avoid any side effects and potential health issues.

Can You Take Magnesium with Other Nutrients?

Magnesium is one of the best minerals to take alongside certain nutrients. It can help enhance absorption by boosting the function of key enzymes involved in converting and using specific nutrients.


Calcium is often paired together with magnesium in supplements as without magnesium, calcium doesn't quite absorb into the right places. It's recommended to take the same dose of calcium and magnesium together for optimal absorption.

Vitamin D

Another key nutrient for bone health, is regulated by magnesium. It's vital to be taking in enough magnesium and vitamin D in the correct doses, when they will work best together.


Zinc and magnesium are also a power pair and can be very advantageous when taken together in the correct doses. Magnesium helps to regulate zinc levels, while zinc enables magnesium to absorb efficiently.

Vitamin B

Vitamin B and magnesium also work well together to promote optimal nervous system function, particularly as they both contribute to energy yielding metabolism and reduce fatigue.

The Best Magnesium Supplement

Performance Lab NutriGenesis Multi

Magnesium is great to take as a standalone supplement, however, as we have discussed, it's often more beneficial to take it alongside other nutrients.

Magnesium can really help to enhance the absorption and use of certain nutrients in the body, so it wouldn't be a bad idea to supplement alongside other nutrients!

This could be in the form of a multi-mineral supplement, or a multivitamin, which includes all the essential micronutrients needed for optimal health.

Performance Lab NutriGenesis Multi is the top recommended multivitamin to cover the bases of all key nutrients, including magnesium.

This ultramodern multivitamin contains all the essential vitamins and minerals you need, in the exact amounts you need them, for optimal health, wellbeing, and peak performance.

This supplement can help restore any nutrients that may be missing from your diet, helping to bridge any nutrient gaps, therefore supporting healthy cell performance across all body systems!

Magnesium FAQ

Q: Can you overdose on magnesium?

A: It is possible to overdose on magnesium, as it is with many supplements. A magnesium overdose is known as hypermagnesemia, which is rare but still possible. These symptoms include nausea, low blood pressure, headache, and irregular heartbeat.

It's important to always stick to the recommended dose and ensure you do not take more than the dosage guidelines on the supplement.

Q: Are magnesium supplements safe to take daily?

A: Yes, provided you are taking the recommended dose and not exceeding the guidelines.

Q: When should I take my magnesium supplement?

A: Some professionals suggest taking magnesium in the evening due to the muscle relaxing effects, which can help achieve a restful night's sleep. However, there is also no harm in taking your supplement in the morning or afternoon - whenever you best remember to take it.

Q: How long should I take a magnesium supplement for?

A: It is safe to take magnesium supplements long-term, though it is always important to seek advice from your doctor to check you are not exceeding the recommended intake.

Q: Can magnesium tablets make you itchy?

A: If you experience itching after taking magnesium tablets, you may be having an allergic reaction. It's important to consult your doctor if you do experience this symptom.

It can be common to experience an itchy/tingling feeling when applying a transdermal magnesium. This is harmless and often an indicator of low magnesium levels.

Take-Home Message

Magnesium is one of the most important minerals for our health and optimal bodily function. Low magnesium levels can cause many health issues, and surprisingly, deficiency can be common.If you're considering a magnesium supplement, there are a few things to remember:

  • Stick to the optimal dose and do not exceed any recommended intakes
  • Taking magnesium alongside other key nutrients can be more advantageous than taking it alone
  • You can also take magnesium in transdermal form, which would be particularly beneficial to those who regularly exercise
  • Magnesium begins to take effect after one week of consistent supplementation
  • A multivitamin such as Performance Lab NutriGenesis Multi would be the most beneficial supplement to take