Overview

SCIENTIFIC SCORE
Questionable
Based on 22 Researches
6.8
USERS' SCORE
Moderately Good
Based on 159 Reviews
7.7
Supplement Facts
Serving Size: 1 Veg Capsule
Amount Per Serving
%DV
Magnesium (elemental) (from Magnesium Oxide, Magnesium Citrate and Magnesium Aspartate)
400 mg
95%

Top Medical Research Studies

9
We explored the effectiveness of magnesium oxide (MgO) as a treatment for chronic constipation using a robust randomized, placebo-controlled trial. Over 28 days, participants received MgO, senna, or a placebo.

Both MgO and senna significantly improved bowel movement frequency and quality of life compared to placebo. About 68.3% of those using MgO reported symptom improvement, showcasing its potential as an effective osmotic agent alongside a stimulant laxative.

Importantly, there were no severe treatment-related side effects reported during the trial.
Read More
4
Effectiveness of magnesium on constipation
We explored how changing the frequency of magnesium oxide (MgO) doses influences its effectiveness in relieving constipation. In this study, we looked at 11 patients who had been regularly using MgO to manage their bowel movements and decided to reduce their daily dose frequency over two weeks.

Initially, patients were taking magnesium three times a day, but we reduced this to either two or one dose per day while keeping the total amount the same. We found that the average number of bowel movements dropped from 7.6 to 6.6 in this period. However, this change wasn't statistically significant, indicating that it may not be clinically meaningful.

Additionally, we measured stool consistency using the Bristol Stool Form Scale and noted no significant difference before and after the dosage adjustment. Our findings suggest that reducing the number of doses does not impact the laxative effect of magnesium oxide. This implies that patients can comfortably manage their magnesium intake without sacrificing effectiveness.
Read More
9
Magnesium effectively aids constipation
We investigated how magnesium supplements affect chronic constipation through a systematic review of randomized controlled trials. The analysis included eight studies with a total of 787 participants. We focused on magnesium oxide among other treatment options and assessed its effectiveness in increasing stool frequency and improving consistency.

The findings were quite promising for magnesium oxide. Our results showed that participants who took magnesium experienced a boost in bowel movements, with an average increase of about 3.7 additional movements per week. This improvement in stool consistency was also noteworthy, scoring higher on the Bristol stool chart.

While other supplements like senna and kiwifruit were explored, they didn't significantly enhance symptoms of constipation in this analysis. Therefore, we suggest that magnesium oxide stands out in this study as a worthwhile option for managing chronic constipation. But it’s essential to remember that further research could help confirm these findings and explore the effects of whole food alternatives.
Read More

Most Useful Reviews

7.5
Effective for constipation
226 people found this helpful
I’ve been taking magnesium for a long time and am always pleased with the results. It calms and acts as a mild laxative, making it great for those suffering from constipation. My family and I all take one capsule a day and it keeps us happy!
Read More
9
Effective for constipation
17 people found this helpful
I love Fierce Magnesium. It works faster than other forms and helps me sleep well. I find it gentle on an empty stomach and it doesn’t irritate me. I also noticed an improvement in my bowel movements, which is beneficial for constipation.
Read More
8
Relieves constipation
17 people found this helpful
I introduced magnesium to help my elderly mother with sleep and constipation issues. It works well for her; she takes a capsule before bed and has noticed improvements in her sleeping and leg cramps. The magnesium oxide form helps her with her constipation effectively.
Read More

Medical Researches

SCIENTIFIC SCORE
Questionable
Based on 22 Researches
6.8
  • All Researches
We explored the relationship between magnesium supplementation, defecation, and cognitive performance in elite triathletes. In a carefully designed crossover trial, participants undertook cognitive tests after taking magnesium oxide and after defecation. This study highlighted an interesting potential connection between the state of our digestive system and cognitive abilities.

We found that after magnesium-induced defecation, participants completed cognitive tasks more quickly compared to when they had not defecated. Specifically, the average completion time for the cognitive test dropped significantly after defecation when magnesium was involved. While this suggests that magnesium can aid in relieving constipation, its role in improving overall cognitive function during athletics is also noteworthy.

Although we observed an increase in cognitive performance following magnesium supplementation, it’s important to note that no significant changes in blood flow or oxygen levels were detected in the brain during the test. Instead, we noted decreased oxygen levels in the digestive region, hinting at an increased demand for energy there.

Overall, our findings suggest a potential new avenue for enhancing cognitive function in athletes through magnesium to improve constipation. However, the direct effects of magnesium solely on constipation require further investigation.
Read More
9
Magnesium effectively aids constipation
We investigated how magnesium supplements affect chronic constipation through a systematic review of randomized controlled trials. The analysis included eight studies with a total of 787 participants. We focused on magnesium oxide among other treatment options and assessed its effectiveness in increasing stool frequency and improving consistency.

The findings were quite promising for magnesium oxide. Our results showed that participants who took magnesium experienced a boost in bowel movements, with an average increase of about 3.7 additional movements per week. This improvement in stool consistency was also noteworthy, scoring higher on the Bristol stool chart.

While other supplements like senna and kiwifruit were explored, they didn't significantly enhance symptoms of constipation in this analysis. Therefore, we suggest that magnesium oxide stands out in this study as a worthwhile option for managing chronic constipation. But it’s essential to remember that further research could help confirm these findings and explore the effects of whole food alternatives.
Read More
9
Magnesium aids cancer patient care
We conducted a randomized, double-blind trial to assess how magnesium-L-threonate, a new compound, might help relieve constipation while enhancing the pain relief effects of opioids in patients with advanced cancer. During the study, patients receiving this treatment were compared with those taking a placebo, allowing us to clearly see the differences in outcomes.

As the trial progressed, we noticed significant improvements in the group taking magnesium-L-threonate. Notably, this treatment not only helped in managing pain more effectively but also significantly alleviated opioid-induced constipation—a common side effect of opioid use. The data indicated that patients on magnesium-L-threonate required lower doses of opioids for pain management while enjoying better gastrointestinal comfort.

Overall, our findings suggest that magnesium-L-threonate is a promising option in the palliative care landscape for cancer patients, addressing both pain relief and constipation, which can greatly enhance their quality of life.
Read More
9
Magnesium may alleviate constipation
We examined the effectiveness of oral magnesium sulfate in treating chronic constipation for children with spastic cerebral palsy. In our study, 100 children received either magnesium sulfate or a placebo for one month.

After this period, we noticed significant improvements in bowel movement frequency and stool consistency in the magnesium group, while the placebo group showed minimal change.

This treatment not only alleviated constipation but also reduced the distress of painful bowel movements for both children and their mothers.
Read More
9
We explored the effectiveness of magnesium oxide (MgO) as a treatment for chronic constipation using a robust randomized, placebo-controlled trial. Over 28 days, participants received MgO, senna, or a placebo.

Both MgO and senna significantly improved bowel movement frequency and quality of life compared to placebo. About 68.3% of those using MgO reported symptom improvement, showcasing its potential as an effective osmotic agent alongside a stimulant laxative.

Importantly, there were no severe treatment-related side effects reported during the trial.
Read More

User Reviews

USERS' SCORE
Moderately Good
Based on 159 Reviews
7.7
  • All Reviews
  • Positive Reviews
  • Negative Reviews
7.5
Effective for constipation
226 people found this helpful
I’ve been taking magnesium for a long time and am always pleased with the results. It calms and acts as a mild laxative, making it great for those suffering from constipation. My family and I all take one capsule a day and it keeps us happy!
Read More
9
Effective for constipation
17 people found this helpful
I love Fierce Magnesium. It works faster than other forms and helps me sleep well. I find it gentle on an empty stomach and it doesn’t irritate me. I also noticed an improvement in my bowel movements, which is beneficial for constipation.
Read More
8
Relieves constipation
17 people found this helpful
I introduced magnesium to help my elderly mother with sleep and constipation issues. It works well for her; she takes a capsule before bed and has noticed improvements in her sleeping and leg cramps. The magnesium oxide form helps her with her constipation effectively.
Read More
9
Improves digestion
11 people found this helpful
This supplement has effectively alleviated nervous and muscle tension. Symptoms such as anxiety and constipation indicate a magnesium deficiency, but dietary intake is often insufficient. After two years of regular use, my quality of life has greatly improved, enabling normal bowel movements without discomfort.
Read More
9
Aids in constipation
10 people found this helpful
Magnesium is essential! Just one capsule helps me sleep soundly and maintains strong bones, as confirmed by my dentist. It’s crucial for muscle function and supports overall health, including alleviating constipation, which I’ve benefited from.
Read More

Frequently Asked Questions

9
Great for constipation
7 people found this helpful
Nou Foods' magnesium is wonderful! I take it at night, and it helps me sleep while relieving constipation. I noticed results the very next day, which has greatly improved my overall health. This supplement is definitely worth it.
7.5
Eases constipation
5 people found this helpful
This supplement works well; it’s effective for constipation. I found that taking it before bed led to a successful bowel movement in the morning without stomach pain. It's recommended for days off or holidays for optimal results.
9
Hormonal balance
6 people found this helpful
After years of struggling with constipation, I discovered magnesium. The results were remarkable! My symptoms improved, especially during PMS. I now take it daily and maintain regular bowel movements.
7.5
Adjustable dosage
4 people found this helpful
I bought it for constipation. If I take one tablet at night, I will have a bowel movement the next day. Continuous daily use may lead to loose stools and slight stomach discomfort, so I adjust to every other day. It's affordable and of decent quality.
7.5
Effective for constipation
226 people found this helpful
I’ve been taking magnesium for a long time and am always pleased with the results. It calms and acts as a mild laxative, making it great for those suffering from constipation. My family and I all take one capsule a day and it keeps us happy!
9
Regular bowel movements
8 people found this helpful
After taking this magnesium, I have regular and well-formed bowel movements without discomfort. I realised I wasn’t getting enough magnesium, and now I always keep it in stock to ensure my digestive health is maintained.
9
Normal bowel movements
3 people found this helpful
It’s incredible! I take three tablets daily and also add magnesium chelate in my bath for further benefits. After years of constipation, I now have regular bowel movements with one pill at night, which is almost painless. I adjust the dose based on my needs.
9
Improved sleep
5 people found this helpful
Taking magnesium before bed has helped me address both constipation and insomnia. It's more effective than laxatives, and I feel it provides essential minerals I need.
9
Effective relief
5 people found this helpful
For several years, I have taken one Now Foods Magnesium Cap every morning alongside Now Foods P-5-P Vitamin B, which improves magnesium absorption. Together, they effectively prevent constipation, a common side effect of the medications I take. I am very satisfied with the results.
9
Invigorating effect
3 people found this helpful
This magnesium is fantastic for constipation. I take three capsules daily, with the last one two hours before bedtime, ensuring everything is expelled by morning. It's effective and can also invigorate and energise.
9
Relieves constipation
3 people found this helpful
This product is essential for alleviating severe constipation with just two pills. It's also effective in preventing calf cramps at night. Some people take up to four pills for serious cases, but I find that two is sufficient.
9
Magnesium effectively aids constipation
We investigated how magnesium supplements affect chronic constipation through a systematic review of randomized controlled trials. The analysis included eight studies with a total of 787 participants. We focused on magnesium oxide among other treatment options and assessed its effectiveness in increasing stool frequency and improving consistency.

The findings were quite promising for magnesium oxide. Our results showed that participants who took magnesium experienced a boost in bowel movements, with an average increase of about 3.7 additional movements per week. This improvement in stool consistency was also noteworthy, scoring higher on the Bristol stool chart.

While other supplements like senna and kiwifruit were explored, they didn't significantly enhance symptoms of constipation in this analysis. Therefore, we suggest that magnesium oxide stands out in this study as a worthwhile option for managing chronic constipation. But it’s essential to remember that further research could help confirm these findings and explore the effects of whole food alternatives.
We investigated how magnesium hydroxide syrup affects constipation among patients recovering from acute myocardial infarction in an intensive care unit (ICU). Participants were divided into two groups: one received magnesium hydroxide syrup daily, while the other was given flaxseed powder. Our aim was to determine which treatment better supported bowel movements in these patients.

The findings revealed that magnesium hydroxide syrup indeed plays a role in managing constipation. Patients taking this syrup experienced their first bowel movement significantly sooner, averaging just under 25 hours. Although both treatments increased bowel movement frequency and improved stool consistency, the differences between the two groups were not statistically significant. In other words, while magnesium did help prompt quicker bowel movements, it wasn't drastically better than flaxseed powder in terms of the overall outcomes.

Overall, the study highlights magnesium hydroxide syrup as a viable option for easing constipation for patients in recovery, though its effectiveness is comparable to that of flaxseed powder. The time to the first defecation was notably quicker with magnesium, suggesting its potential utility in clinical settings where prompt relief is crucial.
8
Magnesium's role in constipation treatment
We aimed to understand how magnesium, particularly when combined with probiotics, influences bowel movements in elderly orthopedic patients suffering from chronic constipation. A retrospective chart review allowed us to analyze various patient records, focusing specifically on the treatments they received and the outcomes.

Magnesium is often talked about as a potential remedy for constipation because it can help draw water into the intestines, making it easier to pass stools. However, since our study also involved probiotics, which can also impact gut health, it becomes harder to isolate the specific effects of magnesium alone.

After reviewing the data, we observed that the combination of magnesium and probiotics did not show a significant advantage in improving bowel movements for the patients involved. This indicates that while magnesium may play a supportive role, its effectiveness on constipation could vary depending on individual circumstances and may not be as pronounced when combined with other treatments.

Overall, this study serves as a reminder of the complexity of managing constipation, especially in the elderly population, where multiple factors can come into play.
4
Magnesium and hypermagnesemia risk
We explored the relationship between magnesium treatment and constipation by examining the risk of developing hypermagnesemia, particularly in older adults. Our study focused on individuals prescribed magnesium oxide (MgO) to alleviate constipation over an extended period.

We included 35 patients who experienced hypermagnesemia and 140 who did not, allowing us to pinpoint specific risk factors. Our findings revealed that reduced kidney function, indicated by a low estimated creatinine clearance (eCcr) of 28.2 mL/min or lower, significantly correlated with the likelihood of hypermagnesemia. Additionally, while not statistically significant, we noted that a daily dose of 900 mg or more of MgO posed an increased risk.

It's important to highlight that while magnesium oxide is often used to treat constipation, taking too much can lead to serious side effects in those with compromised kidney function. We observed that the incidence of hypermagnesemia climbed notably with higher doses and lower kidney function, stressing the need for careful monitoring in older patients using magnesium supplements.

References

  1. Wei CC, Harris MB, Ye M, Nicholls A, Alkhatib A, et al. Defecation after magnesium supplementation enhances cognitive performance in triathletes. Sports Med Health Sci. 2025;7:102. doi:10.1016/j.smhs.2024.04.001
  2. Watanabe N, Itano A, Ando M, Kawahara M. Effect of reduced daily magnesium oxide doses on laxative effect: a single-center retrospective study. J Rural Med. 2024;19:192. doi:10.2185/jrm.2023-038
  3. Amjadi Suraki S, Bagheri-Nesami M, Nabati M, Moosazadeh M, Habibi E. Flaxseed powder and magnesium hydroxide syrup on the intestinal function of patients with acute myocardial infarction in intensive care units. Caspian J Intern Med. 2024;15:234. doi:10.22088/cjim.15.2.234
  4. Nagamine T. Effect of magnesium oxide with probiotics on bowel movements in elderly orthopedic patients with chronic constipation: a retrospective chart review. Biosci Microbiota Food Health. 2024;43:1. doi:10.12938/bmfh.2023-040
  5. Park CW, Lee J, Hong YH, Kim YS, Suh HJ, et al. Coadministration of Lactulose with Probiotics Ameliorates Loperamide-Induced Constipation in Mice. Prev Nutr Food Sci. 2023;28:427. doi:10.3746/pnf.2023.28.4.427
  6. Ishii H, Sawada R, Shiomi M, Shibuya K. A case-control study showing low creatinine clearance and high magnesium intake as risk factors for hypermagnesemia in older individuals. Magnes Res. 2023;36:23. doi:10.1684/mrh.2023.0513
  7. Sasaki H, Hayashi K, Imamura M, Hirota Y, Hosoki H, et al. Combined resistant dextrin and low-dose Mg oxide administration increases short-chain fatty acid and lactic acid production by gut microbiota. J Nutr Biochem. 2023;120:109420. doi:10.1016/j.jnutbio.2023.109420
  8. van der Schoot A, Creedon A, Whelan K, Dimidi E. The effect of food, vitamin, or mineral supplements on chronic constipation in adults: A systematic review and meta-analysis of randomized controlled trials. Neurogastroenterol Motil. 2023;35:e14613. doi:10.1111/nmo.14613
  9. Suzuki S, Obara T, Ishikawa T, Noda A, Matsuzaki F, et al. No association between major congenital malformations and exposure to Kampo medicines containing rhubarb rhizome: A Japanese database study. Front Pharmacol. 2023;14:1107494. doi:10.3389/fphar.2023.1107494
  10. Kistemaker KRJ, de Graeff A, Crul M, de Klerk G, van de Ven PM, et al. Magnesium hydroxide versus macrogol/electrolytes in the prevention of opioid-induced constipation in incurable cancer patients: study protocol for an open-label, randomized controlled trial (the OMAMA study). BMC Palliat Care. 2023;22:22. doi:10.1186/s12904-023-01143-2
  11. Wu S, Jin T, Ma B, Ji Y, Huang X, et al. Oral application of magnesium-L-threonate enhances analgesia and reduces the dosage of opioids needed in advanced cancer patients-A randomized, double-blind, placebo-controlled trial. Cancer Med. 2023;12:4343. doi:10.1002/cam4.4922
  12. Maezawa M, Inoue M, Satake R, Wakabayashi W, Oura K, et al. Effect of acid suppressant medications on the laxative action of magnesium preparations in patients with opioid-induced constipation: A pharmacovigilance analysis of the FDA Adverse Event Reporting System. Pharmazie. 2023;78:245. doi:10.1691/ph.2023.3624
  13. Takemura M, Niki K, Miyaguchi S, Ueda M. Naldemedine-laxative combination: retrospective inpatient study. BMJ Support Palliat Care. 2024;13:e816. doi:10.1136/spcare-2022-003685
  14. Worona-Dibner L, Vázquez-Frias R, Valdez-Chávez L, Verdiguel-Oyola M. Efficacy, safety, and acceptability of polyethylene glycol 3350 without electrolytes vs magnesium hydroxide in functional constipation in children from six months to eighteen years of age: A controlled clinical trial. Rev Gastroenterol Mex (Engl Ed). 2023;88:107. doi:10.1016/j.rgmxen.2021.12.005
  15. de Campos GRC, Sandy NS, Lomazi EA, Bellomo-Brandao MA. Management of children with functional constipation referred to tertiary care. J Pediatr (Rio J). 2022;98:289. doi:10.1016/j.jped.2021.06.006
  16. Rao SSC, Brenner DM. Efficacy and Safety of Over-the-Counter Therapies for Chronic Constipation: An Updated Systematic Review. Am J Gastroenterol. 2021;116:1156. doi:10.14309/ajg.0000000000001222
  17. Hassanein SMA, Deifallah SM, Bastawy HA. Efficacy of oral magnesium therapy in the treatment of chronic constipation in spastic cerebral palsy children: a randomized controlled trial. World J Pediatr. 2021;17:92. doi:10.1007/s12519-020-00401-0
  18. Morishita D, Tomita T, Mori S, Kimura T, Oshima T, et al. Senna Versus Magnesium Oxide for the Treatment of Chronic Constipation: A Randomized, Placebo-Controlled Trial. Am J Gastroenterol. 2021;116:152. doi:10.14309/ajg.0000000000000942
  19. Kubota M, Ito K, Tomimoto K, Kanazaki M, Tsukiyama K, et al. Lactobacillus reuteri DSM 17938 and Magnesium Oxide in Children with Functional Chronic Constipation: A Double-Blind and Randomized Clinical Trial. Nutrients. 2020;12. doi:10.3390/nu12010225
  20. Ohkubo H, Yoshihara T, Misawa N, Ashikari K, Fuyuki A, et al. Relationship between Stool Form and Quality of Life in Patients with Chronic Constipation: An Internet Questionnaire Survey. Digestion. 2021;102:147. doi:10.1159/000502815
  21. Dupont C, Constant F, Imbert A, Hébert G, Zourabichvili O, et al. Time to treatment response of a magnesium- and sulphate-rich natural mineral water in functional constipation. Nutrition. 2019;65:167. doi:10.1016/j.nut.2019.02.018
  22. Tsuji S, Horiuchi A, Tamaki M, Ichise Y, Kajiyama M, et al. Effectiveness and safety of a new regimen of polyethylene glycol plus ascorbic acid for same-day bowel cleansing in constipated patients. Acta Gastroenterol Belg. 2018;81:485.
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