From the Guidelines
Magnesium supplements, particularly in forms like magnesium oxide, can cause smelly gas as a side effect due to their effect on intestinal water and transit time, leading to incomplete digestion and fermentation by gut bacteria. This is supported by the American Gastroenterological Association-American College of Gastroenterology clinical practice guideline, which notes that magnesium oxide can exert a beneficial effect on constipation-related symptoms but may have limitations, including the potential for adverse effects such as flatulence 1.
Key Considerations
- The guideline suggests that magnesium oxide can be an attractive first-line option for individuals with chronic idiopathic constipation (CIC) due to its efficacy, tolerability, availability, and low cost 1.
- However, it is essential to consider the potential for smelly gas as a side effect, particularly when using magnesium oxide, and to take steps to minimize this effect, such as starting with a lower dose and gradually increasing, taking magnesium with food, and splitting the daily dose into smaller amounts 1.
- Other forms of magnesium, such as magnesium glycinate, magnesium malate, or magnesium taurate, may be less likely to cause digestive issues and smelly gas, but their bioavailability and clinical efficacy for CIC are unknown 1.
Recommendations
- Start with a lower dose of magnesium oxide (around 500 mg/d to 1 g/d) and gradually increase as needed, while monitoring for adverse effects such as smelly gas 1.
- Consider taking magnesium with food to minimize gas production and splitting the daily dose into smaller amounts to make it easier for the body to process.
- If the problem persists, consider switching to more easily absorbed forms of magnesium, such as magnesium glycinate, magnesium malate, or magnesium taurate, but be aware that their efficacy and bioavailability for CIC are unknown 1.
From the Research
Magnesium and Smelly Gas
- Magnesium is an essential mineral that can be found in various forms, including magnesium oxide, magnesium citrate, and magnesium malate.
- Some studies have investigated the effects of magnesium compounds on gastrointestinal symptoms, including bloating and gas 2, 3.
- A study published in 2011 found that a combination of simethicone, activated charcoal, and magnesium oxide (Carbosymag®) was effective in reducing dyspeptic symptoms, including abdominal bloating, in patients with functional dyspepsia 2.
- Another study published in 2019 found that different magnesium compounds, including magnesium citrate and magnesium malate, had varying absorption profiles and effects on tissue magnesium levels 3.
- However, there is limited evidence to suggest that magnesium itself causes smelly gas.
- Some studies have investigated the use of magnesium citrate and activated charcoal in the treatment of oral poisonings, including aspirin and paraquat overdose 4, 5.
- A study published in 2018 found that magnesium citrate malate was a bioavailable source of magnesium, but the extent of its bioavailability could not be established due to lack of comparative data 6.