Understanding the Differences: Oxide vs. Glycinate
Before exploring the combination, it is crucial to understand the distinct roles and properties of each form of magnesium. They differ significantly in bioavailability, purpose, and impact on the digestive system.
Magnesium Oxide
Magnesium oxide is an inorganic salt with a high concentration of elemental magnesium but very low bioavailability, meaning the body absorbs only a small percentage (around 4-15%). Because it is poorly absorbed, the unabsorbed portion draws water into the intestines, making it an effective osmotic laxative and antacid for short-term relief of constipation and heartburn. It is the most common and inexpensive form available but is not ideal for correcting a long-term magnesium deficiency.
Magnesium Glycinate
Magnesium glycinate is a chelated form, where magnesium is bound to the amino acid glycine. This chelation process dramatically increases its bioavailability, allowing the body to absorb it efficiently without relying on stomach acid. The presence of glycine, a calming neurotransmitter, also gives it beneficial effects for promoting relaxation, supporting sleep quality, and reducing stress. Glycinate is well-tolerated by the digestive system and is much less likely to cause the laxative side effects associated with magnesium oxide.
Synergistic or Overkill? Why People Consider Combining Them
People might consider taking both forms to target different health needs simultaneously. For example, a person might use magnesium glycinate daily for anxiety and sleep support while keeping magnesium oxide on hand for occasional constipation. This approach aims to leverage the specific strengths of each form.
However, combining them requires careful attention to the total dosage to avoid exceeding the Tolerable Upper Intake Level of 350 mg of supplemental magnesium for adults. Excessive intake can lead to hypermagnesemia, a condition with symptoms like nausea, diarrhea, muscle weakness, and in severe cases, more serious complications. The risk of hypermagnesemia is especially high for individuals with impaired kidney function, as the kidneys are responsible for clearing excess magnesium from the body. It is imperative to consult a healthcare provider before combining supplements.
How to Safely Combine Magnesium Supplements
- Targeted Dosing: Use magnesium glycinate for systemic needs like relaxation and mood support, and only use magnesium oxide as needed for digestive relief. This prevents unnecessary high daily intake of the low-bioavailability oxide form.
- Mindful Timing: Take the different forms at separate times of the day. For example, take the calming magnesium glycinate in the evening for sleep and use magnesium oxide during the day with a meal if you require digestive support.
- Monitor Effects: Pay close attention to how your body responds. If you experience any gastrointestinal discomfort from the oxide, you may need to reduce the dose or rely solely on magnesium glycinate, which is gentler on the stomach.
- Check Blended Formulas: Some supplements are sold as a blend of multiple magnesium types. Always check the label to understand the composition and the total elemental magnesium per dose before adding other individual supplements.
Comparison Table: Magnesium Oxide vs. Magnesium Glycinate
| Feature | Magnesium Oxide | Magnesium Glycinate |
|---|---|---|
| Bioavailability | Poor (~4-15% absorbed) | High (well-absorbed) |
| Main Use | Constipation relief, antacid | Relaxation, sleep, stress reduction |
| Gastrointestinal Effects | Laxative effect, can cause diarrhea | Gentle on the stomach, well-tolerated |
| Elemental Magnesium | High percentage per dose | Lower percentage per dose (but better absorbed) |
| Best For | Short-term digestive issues | Long-term supplementation, deficiency correction |
| Cost | Less expensive | More expensive due to chelation |
Choosing What is Right for You
Selecting the right magnesium form depends entirely on your specific health goals. For most people seeking to increase their overall magnesium levels or to aid with sleep and stress, magnesium glycinate is the superior choice due to its high bioavailability and minimal side effects. Its calming properties are a significant benefit. For those needing occasional, short-term relief from constipation, magnesium oxide is a potent and effective option. For chronic constipation, other forms like magnesium citrate may be better choices.
Ultimately, a combined strategy of both oxide and glycinate is possible but rarely necessary, as magnesium glycinate serves the broader purpose of addressing a systemic deficiency effectively. The most sensible approach for many is to choose a single form that aligns with their primary health need. If you choose to combine them, professional medical guidance is essential to ensure safety and prevent adverse effects from over-supplementation.
Conclusion
Taking magnesium oxide and magnesium glycinate together is permissible but requires careful management. Each form serves a different purpose due to its distinct bioavailability and effects on the body. Magnesium glycinate is the ideal choice for addressing a long-term deficiency and promoting relaxation, while magnesium oxide is best reserved for short-term digestive issues like constipation. Combining them can be beneficial for those with specific, dual needs, but the risk of excessive magnesium intake and corresponding side effects should not be overlooked. Always consult with a healthcare provider to determine the best supplementation strategy for your health profile and goals.
