Choosing Melatonin or Magnesium Glycinate for Better Sleep

What are the main differences between melatonin and magnesium glycinate?

Jeff Krupinski, PharmD: Melatonin is a hormone that our bodies naturally produce in our brain. Its primary purpose is to regulate sleep/wake cycles. Melatonin supplementation has been proven effective at improving the time it takes to fall asleep.

Magnesium is a dietary mineral that is essential for many physiological functions including muscle and nerve function, blood pressure regulation, and sleep. Magnesium glycinate is a well-absorbed form that combines magnesium with glycine, a calming neurotransmitter. It is known for being gentle on the digestive system. 

How do these supplements help me sleep?

Jeff Krupinski, PharmD: Melatonin helps regulate the body’s circadian rhythm, endocrine secretions and sleep patterns. 

Magnesium also promotes muscle relaxation. Glycine is itself an inhibitory neurotransmitter, supporting a deeper sleep.

Since they work in different ways, using both together could give an extra benefit.

When is the best time to take these supplements?

Jeff Krupinski, PharmD: Melatonin: For adults, start with 3 to 5 mg taken 30-60 minutes before bed. Higher doses have not been proven to be more effective and would be more likely to cause side effects. Choose the immediate-release form because it mimics circadian release.

Magnesium: Magnesium can be taken at any time of the day, but consistency is key. Splitting the dose into two daily doses with meals would benefit absorption and reduce GI upset. Building up your magnesium stores is what you are trying to achieve. Some benefits can be seen within a few days but allow several weeks for the full effect. 

Look for supplements with 200 mg to 350 mg of elemental magnesium per day. It is very important to note that supplement labels can be very deceiving! 

Look carefully at the Supplement Facts part of the label. For example, a product may show 200 mg on the front of the bottle, but only actually contain 22 mg of elemental magnesium listed in the Supplement Facts.

Which is better for sleep?

Jeff Krupinski, PharmD: Melatonin has been scientifically proven to work but temper your expectations. It may take several weeks of use before you start to feel more rested. 

If you want just a single supplement, go with immediate-release melatonin. But it’s okay to take both.

It may be tempting to take a single product that combines melatonin, magnesium and possibly other supplements combined in one capsule. However, these combination products are often gimmicky and may not contain high enough amounts of the active ingredients to be effective. 

If you prefer a combination product, choose one from a reputable brand with at least 3 mg of melatonin.

Are there any side effects of either?

Jeff Krupinski, PharmD: Both are generally well tolerated but can sometimes cause mild side effects. 

The most common adverse effects reported in melatonin are headache and daytime sleepiness. Less commonly reported side effects include sore throat, joint and back pain.

Taking large amounts of magnesium causes a laxative effect and may cause gastrointestinal discomfort. Magnesium glycinate is unlikely to cause these effects when taken at recommended doses.

 Neither melatonin nor magnesium is addictive or habit-forming.

Are there cardiovascular risks?

A recent study, conducted by Ameican Heart Association, found of over 130,000 adults found that long-term melatonin use (one year or more) was associated with higher risk of heart failure and increased hospitalizations. Experts caution that this is an association, not proof of causation, and insomnia itself may contribute to cardiovascular risk.

Trinity Health Michigan Heart cardiologist, Tanmay Swadia, addressed the news reports and study by saying, "This was an observational study, meaning it can identify associations and links but cannot prove that melatonin caused a higher cardiovascular and heart failure risk.  There may be other factors involved."

What this means for patients:

•    If you have insomnia and are using melatonin long-term or nightly, this study suggests a potential link with increased risk for heart failure and other serious outcomes.  
•    Talk with your healthcare provider about whether melatonin is still the best choice for your sleep issues, based on your overall health.  
•    Monitoring heart health and other risk factors such as blood pressure, diabetes, weight and sleep disorders like sleep apnea.  
•    If you are using melatonin purely occasionally such as for jet lag, shiftwork etc. the implications might be very different and long-term nightly use.

Consider Your Health History 

Supplements may work in a lot of people, but they’re not for everyone. Consult a healthcare provider before starting or stopping any supplement, especially if you have underlying health conditions.

Pharmacists are a valuable member of your health care team. The next time you are in the pharmacy and have a question about medication, please don’t hesitate to ask.

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