Drug & supplement interaction

Magnesium + Neomycin , Polymyxin B

Neomycin , Polymyxin B brand name: Neosporin Cream.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Magnesium and Neomycin , Polymyxin B in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Magnesium and Neomycin , Polymyxin B

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Neomycin , Polymyxin B and Magnesium in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Magnesium safety at a glance

Magnesium overall Generally safe Generally safe for healthy adults when taken at recommended amounts from food and supplements.
Pregnancy Likely Safe When used orally and appropriately. Magnesium is safe for those pregnant and breast-feeding when used in doses below the tolerable upper intake level (UL) of 35... Read the full pregnancy detail
Breastfeeding Likely Safe When used orally and appropriately. Magnesium is safe for those pregnant and breast-feeding when used in doses below the tolerable upper intake level (UL) of 35... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Neomycin , Polymyxin B and Magnesium? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Neomycin , Polymyxin B

Interactions in our licensed database are recorded against drug classes, not just single drug names. Neomycin , Polymyxin B is filed under a single classification — topical drugs. Magnesium has documented interactions with 15 drug classes — the most serious being levodopa/carbidopa (sinemet) (major), aminoglycoside antibiotics (moderate) and antacids (moderate) — and none of Neomycin , Polymyxin B’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Magnesium Does Interact With Other Medications

Magnesium has 6 major, 175 moderate, 114 minor known drug interactions in our database — Neomycin , Polymyxin B isn’t one of them. If you take anything else, check it against the full list below.

Major 6 Moderate 175 Minor 114 No known interaction 2,535 (incl. Neomycin , Polymyxin B)
Taking anything else?

Check Another of Your Medications Against Magnesium

Covers the 2,830 medications we’ve checked against Magnesium. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Magnesium and Neomycin , Polymyxin B May Share a Side Effect

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • Kidney problems Worth acting on Additional detail

    Magnesium

    “Intravenously, magnesium sulfate may cause renal toxicity or acute urinary retention, although these events are rare. A case of slowed cervical dilation at delivery has been reported for a patient administered intravenous magnesium sulfate for eclampsia. Intravenous magnesium might also cause solute diuresis.”

    Magnesium · Natural Medicines adverse-effect record, reported in eclampsia.

    4 sources cited
    1. 60818. Azria, E., Tsatsaris, V., Goffinet, F., Kayem, G., Mignon, A., and Cabrol, D. [Magnesium sulfate in obstetrics: current data]. J Gynecol.Obstet.Biol.Reprod.(Paris) 2004;33(6 Pt 1):510-517.
    2. 61012. McDonald, S. D., Lutsiv, O., Dzaja, N., and Duley, L. A systematic review of maternal and infant outcomes following magnesium sulfate for pre-eclampsia/eclampsia in real-world use. Int J Gynaecol.Obstet. 2012;118(2):90-96. PubMed
    3. 12592. Witlin AG, Sibai BM. Magnesium sulfate therapy in preeclampsia and eclampsia. Obstet Gynecol 1998;92:883-9.. DOI
    4. 98284. Brown RS. Magnesium Sulfate: Another Cause of a Solute Diuresis. Am J Kidney Dis. 2017;69(4):550-551. PubMed

    “Intravenously, magnesium may cause slurred speech, dizziness, drowsiness, confusion, or headaches. With toxic doses, loss of reflexes, neurological defects, drowsiness, confusion, and coma can occur.

    A case report describes cerebral cortical and subcortical edema consistent with posterior reversible encephalopathy syndrome (PRES), eclampsia, somnolence, seizures, absent deep tendon reflexes, hard to control hypertens…”

    Magnesium · Natural Medicines adverse-effect record, reported in epilepsy.

    6 sources cited
    1. 60818. Azria, E., Tsatsaris, V., Goffinet, F., Kayem, G., Mignon, A., and Cabrol, D. [Magnesium sulfate in obstetrics: current data]. J Gynecol.Obstet.Biol.Reprod.(Paris) 2004;33(6 Pt 1):510-517.
    2. 60960. Duley, L., Gulmezoglu, A. M., Henderson-Smart, D. J., and Chou, D. Magnesium sulphate and other anticonvulsants for women with pre-eclampsia. Cochrane.Database.Syst.Rev. 2010;(11):CD000025. PubMed
    3. 114681. Shepherd ES, Goldsmith S, Doyle LW, et al. Magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus. Cochrane Database Syst Rev 2024;5(5):CD004661. PubMed
    4. 8095. Birrer RB, Shallash AJ, Totten V. Hypermagnesemia-induced fatality following epsom salt gargles. J Emerg Med 2002;22:185-8. PubMed
    5. 12589. Jeyabalan A, Caritis SN. Pharmacologic inhibition of preterm labor. Clin Obstet Gynecol 2002;45:99-113. PubMed
    6. 12590. Mittendorf R, Dambrosia J, Pryde PG, et al. Association between the use of antenatal magnesium sulfate in preterm labor and adverse health outcomes in infants. Am J Obstet Gynecol 2002;186:1111-8.. PubMed

    Neomycin , Polymyxin B

    Listed in the ADVERSE REACTIONS section of the FDA label for Neomycin , Polymyxin B. Read the label on DailyMed ›

Reported for Magnesium but not commonly for Neomycin , Polymyxin B: a bowel blockage, trouble passing urine, muscle weakness and heart failure.

Effects for Neomycin , Polymyxin B come from the ADVERSE REACTIONS section of its FDA label; effects for Magnesium come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Magnesium in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When used orally and appropriately. Magnesium is safe for those pregnant and breast-feeding when used in doses below the tolerable upper intake level (UL) of 350 mg daily.

Pregnancy And Lactation Possibly Safe

When prescription magnesium sulfate is given intramuscularly and intravenously prior to delivery for up to 5 days. However, due to potential adverse effects associated with intravenous and intramuscular magnesium, use during pregnancy is limited to patients with specific conditions such as severe pre-eclampsia or eclampsia. There is some evidence that intravenous magnesium can increase fetal mortality and adversely affect neurological and skeletal development. However, a more recent analysis of clinical research shows that increased risk of fetal mortality seems to occur only in the studies where antenatal magnesium is used for tocolysis and not for fetal neuroprotection or pre-eclampsia/eclampsia. Furthermore, antenatal magnesium does not seem to be associated with increased risk of necrotizing enterocolitis in preterm infants. There is also concern that magnesium increases the risk of maternal adverse events. A meta-analysis of clinical research shows that magnesium sulfate might increase the risk of maternal adverse events, especially in Hispanic mothers compared to other racial and ethnic groups.

Pregnancy And Lactation Possibly Unsafe

When used orally in excessive doses. Tell patients to avoid exceeding the tolerable upper intake level (UL) of 350 mg daily. Taking magnesium orally in higher doses can cause diarrhea. ...when prescription magnesium sulfate is given intramuscularly and intravenously prior to delivery for longer than 5 days. Maternal exposure to magnesium for longer than 5-7 days is associated with an increase in neonatal bone abnormalities such as osteopenia and fractures. The U.S. Food and Drug Administration (FDA) recommends that magnesium injection not be given for longer than 5-7 days.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

From our Q&A

Questions About Magnesium or Neomycin , Polymyxin B

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Magnesium or Neomycin , Polymyxin B, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Neomycin , Polymyxin B

This page covers Magnesium only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Neomycin , Polymyxin B page lists 3 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Dimethylsulfoxide (dmso) (moderate), Turpentine Oil (moderate) and Alchemilla (minor).

By severity: 2 moderate · 1 minor.

From our pharmacist’s overview on the Neomycin , Polymyxin B page

“A tube of Neosporin Cream (neomycin and polymyxin B) sits in most medicine cabinets for scrapes and cuts, and its interaction list is refreshingly short, just three supplement ingredients, all of them things you would put on your skin rather than swallow. Nothing rates major, so this is a watch-and-know situation rather than a red flag.”

Reviewed by 2 · Jul 18, 2026

Open the Neomycin , Polymyxin B interaction page

One more smart check

Taking Magnesium as Part of a Dietary Supplement Product? Check It for Interactions

We hold 29,717 real supplement products containing Magnesium, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Magnesium. Even though Magnesium itself has no known interaction with Neomycin , Polymyxin B, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Magnesium and Neomycin , Polymyxin B Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Magnesium
Top 10

#4 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Neomycin , Polymyxin B
Top 25%

#589 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Magnesium reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Magnesium and Neomycin , Polymyxin B records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Magnesium

What is Magnesium?

Magnesium
  • Preventing or treating magnesium deficiency
  • Constipation
  • Muscle cramps
  • Sleep support
  • Anxiety and stress
  • Migraine prevention

Magnesium is an essential mineral your body needs for muscles, nerves, blood pressure, and many other functions, and supplements are useful for preventing or correcting deficiency. Some other uses, like easing constipation or preventing migraines, have reasonable support, while uses for sleep and anxiety are less proven. It is generally safe for most healthy people at recommended amounts, but talk to your pharmacist or doctor before starting, especially if you have kidney problems.

Mineral (not a plant part) · Tablets, capsules, powders, liquids, gummies, and topical Epsom salts; common forms include magnesium citrate, glycinate, oxide, chloride, malate, and aspartate

An interaction check asks whether these two react with each other — it does not ask whether Magnesium is a good idea for someone in your situation. Here is what our Magnesium record says about it on its own.

Magnesium: dosing

There is no single "best" dose for everyone, and the right amount depends on your age, sex, health, and the reason you are taking it. Different forms contain different amounts of actual (elemental) magnesium, which can be confusing.Do not assume more is better. There is an upper limit for magnesium taken as a supplement, and going above it raises the risk of side effects. If you are using magnesium for a specific condition like constipation or migraine, ask a health professional for guidance.

From our Magnesium monograph — the full record covers uses, side effects and every documented interaction.

Read the full Magnesium monograph & all interactions
Keep checking

Other Drugs & Magnesium

Browse every other medication we’ve checked against Magnesium — both the ones with a known interaction and the ones without. Select any drug for the full detail.

6Major
175Moderate
114Minor
2,534No known interaction
6 Major 175 Moderate 114 Minor 2,534 No interaction
Major

6 interactions

Moderate

175 interactions

Showing 60 of 175 moderate interactions — see all 175 on the Magnesium page.

Minor

114 interactions

Showing 60 of 114 minor interactions — see all 114 on the Magnesium page.

No interaction 2,534 drugs checked — show the list

We also checked Magnesium against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,534 medications checked with no known interaction — see the full Magnesium list.

See the full Magnesium interactions page
See every supplement checked against Neomycin , Polymyxin B, ranked by severity
Evidence & sources

Magnesium References

The 82 references that drive our Magnesium monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Rodin SM, Johnson BF. Pharmacokinetic interactions with digoxin. Clin Pharmacokinet 1988;15:227-44.
  2. Covington TR, et al. Handbook of Nonprescription Drugs. 11th ed. Washington, DC: American Pharmaceutical Association, 1996.
  3. Dahle LO, Berg G, Hammar M, et al. The effect of oral magnesium substitution on pregnancy-induced leg cramps. Am J Obstet Gynecol 1995;173:175-80. PubMed
  4. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  5. Peikert A, Wilimzig C, Kohne-Volland R. Prophylaxis of migraine with oral magnesium: results from a prospective, multi-center, placebo-controlled and double-blind randomized study. Cephalalgia 1996;16:257-63. PubMed
  6. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington, DC: National Academy Press, 1999. Available at: http://books.nap.edu/books/0309063507/html/index.html.
  7. Birrer RB, Shallash AJ, Totten V. Hypermagnesemia-induced fatality following epsom salt gargles. J Emerg Med 2002;22:185-8. PubMed
  8. Ryan MP. Diuretics and potassium/magnesium depletion. Directions for treatment. Am J Med 1987;82:38-47.. PubMed
  9. Hollifield JW. Magnesium depletion, diuretics, and arrhythmias. Am J Med 1987;82:30-7.. PubMed
  10. Heidenreich O. Mode of action of conventional and potassium-sparing diuretics--aspects with relevance to Mg-sparing effects. Magnesium 1984;3:248-56..
  11. Pfaffenrath V, Wessely P, Meyer C, et al. Magnesium in the prophylaxis of migraine--a double-blind placebo-controlled study. Cephalalgia 1996;16:436-40.. PubMed
  12. Wang F, Van Den Eeden SK, Ackerson LM, et al. Oral magnesium oxide prophylaxis of frequent migrainous headache in children: a randomized, double-blind, placebo-controlled trial. Headache 2003;43:601-10.. PubMed
  13. Sompolinsky D, Samra Z. Influence of magnesium and manganese on some biological and physical properties of tetracycline. J Bacteriol 1972;110:468-76.. PubMed
  14. Jeyabalan A, Caritis SN. Pharmacologic inhibition of preterm labor. Clin Obstet Gynecol 2002;45:99-113. PubMed
  15. Mittendorf R, Dambrosia J, Pryde PG, et al. Association between the use of antenatal magnesium sulfate in preterm labor and adverse health outcomes in infants. Am J Obstet Gynecol 2002;186:1111-8.. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Magnesium and Neomycin , Polymyxin B Together: Common Questions

Is it safe to take Magnesium with Neomycin , Polymyxin B?
We do not list a known interaction between Magnesium and Neomycin , Polymyxin B. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Magnesium and Neomycin , Polymyxin B have any of the same side effects?
Yes — our sources link each of them separately to one of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Magnesium and Neomycin , Polymyxin B combination checked?
Interactions in our licensed database are recorded against drug classes. Neomycin , Polymyxin B is filed under 1 classification, and Magnesium has documented interactions with 15 drug classes — none of Neomycin , Polymyxin B's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Magnesium interact with any other medications?
Yes. Magnesium has 295 documented drug interactions in our database — Neomycin , Polymyxin B is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Neomycin , Polymyxin B interact with any supplements?
Yes. Neomycin , Polymyxin B has documented interactions with 3 supplements in our database — Magnesium is not one of them. The Neomycin , Polymyxin B interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Magnesium monograph Uses, safety profile, and every drug interaction in one place Neomycin , Polymyxin B supplement interactions Every supplement checked against Neomycin , Polymyxin B, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 82 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Neomycin , Polymyxin B and Magnesium?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.