Magnesium Glycinate Side Effects: What You Need To Know

What you need to know about magnesium glycinate side effects

• Magnesium glycinate is generally well tolerated, though mild digestive side effects can occur, particularly when taking more than the recommended amount.
• Understanding the possible side effects of magnesium glycinate can help you recognise what's normal, when to adjust your dose, and when to seek medical advice.
• Taking magnesium glycinate as directed, paying attention to how your body responds, and avoiding excessive doses can help minimise unwanted side effects.

Thinking about taking magnesium glycinate? Or perhaps you've already started and want to know what to expect. Either way, understanding the possible side effects can help you feel more confident about using it. 

Magnesium glycinate, a form of magnesium bound to the amino acid glycine, is generally well absorbed by the body and well tolerated by most people¹. While side effects are uncommon, knowing what they can look like, when they might happen, and when it's worth speaking to a healthcare professional can help you make informed choices. 

This guide covers some side effects of magnesium glycinate which may occur, what can happen if you take too much, and practical tips for using it confidently. 

What is magnesium glycinate and what are its effects?

Magnesium glycinate is magnesium bound to the amino acid glycine. This form tends to be gentler on the digestive system2. It’s often associated with calming effects on the nervous system, which can be useful for people experiencing stress or looking to improve sleep quality1.

Magnesium is involved in a wide range of physiological processes. From supporting muscle function and repair to nervous system and cardiovascular health, it plays an important role across different systems in the body3. 

Common side effects of magnesium glycinate

While most people tolerate magnesium glycinate well, some mild digestive symptoms may occur, particularly when you begin taking it. Symptoms can also occur if you’re taking a higher dose than the body is used to⁴. 

Commonly known side effects include symptoms like nausea, loose stools, or stomach discomfort⁴. These symptoms are generally temporary and will often improve once your body has adjusted. However, everyone responds to supplements differently, so while one person may notice mild digestive changes, another may experience no side effects at all. 

Can magnesium glycinate cause nausea?

Yes, nausea may be a side effect of taking magnesium glycinate, especially if taken on an empty stomach. However, magnesium glycinate and nausea are less commonly linked together than with some other magnesium forms, since this form tends to be gentler on the digestive system⁴. 

Taking it with food and starting with a lower dose, then gradually increasing over time, can help the body adjust. The timing of your supplement can also make a difference. Some people find taking it alongside a meal is more comfortable than taking it first thing in the morning or on an empty stomach. It’s always best to talk to your GP if nausea continues despite adjusting how or when you take it. 

What happens if you take too much magnesium glycinate? 

Too much magnesium from food doesn't pose a health risk for most healthy people, since the kidneys clear the excess5. Magnesium supplements can be a little different. Taking high doses may cause some side effects, while very high doses can lead to magnesium toxicity4 5. 

If you’ve had too much magnesium glycinate, you might experience symptoms like: 

• Digestive upset5 
• Diarrhoea5
• Nausea5 
• Abdominal cramping5
• Feeling unusually drowsy5
• Headaches and dizziness5
• Low blood pressure5

It’s also worth noting that the risk of magnesium toxicity is higher for people with impaired kidney function, since the kidneys play the main role in clearing excess magnesium from the body6. 

Should you be worried about the effects of magnesium glycinate?

For most people, magnesium glycinate is well tolerated, and side effects are typically mild, dose-related, and manageable. 

A few simple steps can help you add it to your routine with confidence:

• Start with the recommended serving size rather than taking more straight away.
• Take it with food if you have a sensitive stomach.
• Pay attention to how your body responds, especially when first starting.
• Find the time of day that suits you and your body. 
• Reduce your intake and speak to a healthcare professional if symptoms persist.
• Check with a healthcare professional first if you take prescription medication or have an existing health condition.

H2: Adding magnesium to your daily routine 

Once you know what to expect, adding magnesium glycinate to your routine doesn't need to be complicated. Following the directions on the product label and using it as part of your everyday routine can help you get the most from your supplement while reducing the likelihood of unwanted side effects.

It's also worth remembering that supplements are designed to complement, not replace, a balanced diet and healthy lifestyle. Magnesium-rich foods, regular movement, quality sleep and other everyday habits all play a role in supporting overall wellbeing. If you're unsure whether magnesium glycinate is the right choice for you, a healthcare professional can help you decide what's right for your needs.

Want to learn more about magnesium? Discover articles like the importance of magnesium and a guide to the different types of magnesium on the Swisse Wellness Hub. 

References:

1. Cepeda V, Ródenas-Munar M, García S, Bouzas C, Tur JA. Unlocking the Power of Magnesium: A Systematic Review and Meta-Analysis Regarding Its Role in Oxidative Stress and Inflammation. Antioxidants (Basel). 2025 Jun 16;14(6):740. doi: 10.3390/antiox14060740. PMID: 40563371; PMCID: PMC12189353. 
2. Schuchardt, J. P., & Hahn, A. (2017). Intestinal absorption and factors influencing bioavailability of magnesium: An update. Current Nutrition & Food Science, 13(4), 260–278. https://doi.org/10.2174/1573401313666170427162740 
3. Fatima, G., Dzupina, A., B Alhmadi, H., Magomedova, A., Siddiqui, Z., Mehdi, A., & Hadi, N. (2024). Magnesium matters: A comprehensive review of its vital role in health and diseases. Cureus, 16(10), e71392. https://doi.org/10.7759/cureus.71392 
4. National Institutes of Health, Office of Dietary Supplements. (2022). Magnesium: Fact sheet for consumers. U.S. Department of Health and Human Services. https://ods.od.nih.gov/factsheets/Magnesium-Consumer/ 
5. National Institutes of Health, Office of Dietary Supplements. (2023). Magnesium: Fact sheet for health professionals. U.S. Department of Health and Human Services. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/ 
6. Adomako, E. A., & Yu, A. S. L. (2024). Magnesium disorders: Core curriculum 2024. American Journal of Kidney Diseases, 83(6), 803–815. https://doi.org/10.1053/j.ajkd.2023.09.023