Recently, a type of topical magnesium salt went viral on “Threads,” sparking widespread interest in how magnesium helps with sleep. But what exactly are the functions of magnesium in the human body? And which is more effective: external application or internal consumption? Let Pharmacist Ting-Yu Chou guide you through the benefits, recommended intake, and supplementation methods of magnesium!
Why is Poor Sleep Linked to Magnesium?
Magnesium is a vital mineral that acts as a cofactor for many enzymes and chemical reactions in the body. It is involved in the production of serotonin and the secretion of melatonin. Furthermore, it acts on GABA receptors, which have sedative and calming functions. Consequently, magnesium can help reduce anxiety, promote a state of mental calmness and relaxation, and effectively alleviate insomnia.
Research shows that supplementing with 200–400 mg of magnesium one hour before bedtime can help improve sleep quality. Beyond sleep, magnesium also aids in the secretion of dopamine, norepinephrine, and epinephrine, playing a crucial role in blood sugar regulation, the nervous system, bone health, and muscle tissue function.
Four Common Forms of Magnesium: Absorption Rates Vary!
Can topical magnesium truly provide stress relief and sleep aid? Scientific evidence suggests that magnesium ions are actually very difficult to absorb through the skin. The magnesium salts trending on social media may feel effective primarily due to their fragrance or the relaxation provided by the massage itself. If you want to improve sleep quality through magnesium, it is more effective to obtain it through diet or oral supplements.
Since the human body cannot synthesize magnesium, it must be consumed through diet. Foods high in magnesium include seaweed, nuts, deep green leafy vegetables, legumes, and seafood. Alternatively, you can use supplements to ensure adequate intake.
The four most common forms of magnesium supplements on the market are:
| Type | Recommendation |
| Magnesium Oxide | The most common form. It has an absorption rate of only 3-4% and increases intestinal peristalsis. It is typically used as a stool softener and is not recommended as a primary source for magnesium supplementation. |
| Magnesium Citrate | Has a higher absorption rate and is affordable, but it can easily cause gastrointestinal discomfort or diarrhea. |
| Magnesium Gluconate | Absorption is lower than citrate or glycinate, and it is relatively expensive. |
| Magnesium Glycinate | The most absorbable form. it does not cause diarrhea and releases glycine upon absorption, which helps produce serotonin. It is the best “two-in-one” choice for those needing neuromuscular relaxation and improved sleep quality. |
Who Needs Magnesium Supplementation?
There are many causes of magnesium deficiency. Some people lose magnesium due to medication or poor gastrointestinal absorption, but for most, it is due to insufficient dietary intake. According to the Dietary Reference Intakes (DRIs), the recommended daily allowance (RDA) for adults is 380mg for men and 320mg for women, with an upper limit of 700mg.
Surveys show that nearly 80% of people in Taiwan do not meet the recommended daily intake. The following groups should be particularly mindful of magnesium deficiency:
- Those with diets high in meat, low in vegetables, or high in fat and sugar, or those who frequently consume processed foods with added phosphates (which hinder absorption).
- People with hypertension, diabetes, or metabolic syndrome.
- Individuals with chronic diarrhea or gastrointestinal diseases that affect absorption.
- Those taking long-term medications such as antacids (PPIs), anti-inflammatories, antibiotics, diuretics, or steroids.
- Athletes or those who sweat excessively.
- People who consume alcohol excessively.
- Those prone to nervousness, insomnia, depression, or anxiety.
A Final Reminder: If you have impaired kidney function, you must consult a physician before supplementing with magnesium to avoid placing an extra burden on your kidneys!
Q&A
1. What are common symptoms of magnesium deficiency?
Magnesium helps our mind and body relax. Therefore, a deficiency can lead to mood swings, tension, anxiety, fatigue, and a general sense of malaise. Other symptoms include loss of appetite, limb weakness, muscle cramps, dizziness, headaches, memory decline, disrupted circadian rhythms, and insomnia. If these symptoms occur repeatedly, it is recommended to have your magnesium levels tested.
2. If my calcium tablets already contain magnesium, do I still need extra?
Generally, the magnesium added to calcium tablets is Magnesium Oxide. Its primary purpose is to balance the digestive side effects of calcium (such as constipation). Since Magnesium Oxide has an absorption rate of only about 3%, if you need to address a true deficiency or improve sleep, it is still recommended to supplement separately with Magnesium Glycinate.