Natural Ingredients for Muscle Aches and Joint Pain: Epsom Salt, Magnesium and Others
Epsom salt baths, magnesium oil and magnesium for cramps are popular for sore muscles and joints. See what trials found, where evidence is missing, and the swallowing risks.
Content last updated . This page has not been medically reviewed.
Safety first. Natural products can cause side effects and interact with medicines. Read natural ingredient safety before you use anything on this page.
Epsom salt is for bathing, not for swallowing. Case reports describe severe magnesium overload, with weakness, low blood pressure, altered mental status and breathing failure, after Epsom salts were swallowed as a laxative. [1] If someone has swallowed it and is confused, faint or struggling to breathe, call 911. For other swallowing questions, call Poison Help at 1-800-222-1222.
The claim, as marketed
Epsom salt (magnesium sulfate) baths, "magnesium oil" sprays and magnesium flakes are promoted for sore muscles, cramps and joint pain, often with the idea that magnesium is absorbed through the skin. This page asks what has been tested in people. It covers ingredients only. Back pain, arthritis and injury care are covered elsewhere, and a painful joint that is hot, swollen or injured needs a clinician.What research found
| Ingredient and use | What the source found | Strength of evidence | Who and what was studied |
|---|---|---|---|
| Epsom salt baths for knee osteoarthritis | In a randomized trial the group given Epsom salt baths for seven days reported less pain and better daily activity than the group given standard care. [2] | Promising but limited | 64 adults with knee osteoarthritis; the comparison group had standard care, and no plain-water bath was described in the abstract [2] |
| Epsom salt baths for sore muscles after exercise | Proper evidence not found. We searched PubMed for Epsom salt bath trials in muscle soreness and found trials in knee osteoarthritis and cancer-treatment nerve symptoms, but none in exercise soreness that we could read. | Insufficient evidence | Not applicable |
| Magnesium absorbed through the skin (oils, sprays, flakes, baths) | A 2017 review of the literature concluded that the propagation of transdermal magnesium is scientifically unsupported. [3] We did not find a trial of magnesium oil for muscle pain that we could read. | Marketing claim, insufficient evidence | Review of the literature, not a new trial [3] |
| Magnesium swallowed for muscle cramps | A Cochrane review of 11 trials found that for cramps with no clear cause, mostly in older adults, differences in cramp frequency between magnesium and placebo were small and not statistically significant. [4] | No good evidence of benefit for this use | All but one trial gave magnesium as an oral supplement, not a bath or oil [4] |
What a reader can safely do
Ask a pharmacist about proven pain relief for your situation, since the NHS suggests this for sprains and strains. [5] If skin is broken or inflamed, ask a clinician or pharmacist before using any bath product.Frequently asked questions
Does Epsom salt help sore muscles?
We found no trial in exercise soreness. One small trial in knee osteoarthritis reported less pain after seven days of baths compared with standard care. [2]
Is magnesium absorbed through the skin?
A 2017 review concluded that claims for transdermal magnesium are scientifically unsupported. [3]
Does magnesium stop muscle cramps?
A Cochrane review found that magnesium by mouth made little or no difference to cramp frequency in cramps without a clear cause. [4]
Is it safe to drink Epsom salt?
Case reports describe severe magnesium overload after swallowing it as a laxative. [1] Call Poison Help at 1-800-222-1222 about any swallowing question.
When should muscle or joint pain be checked?
When it is very painful, getting worse, or you cannot bear weight, the NHS says to get help. [5]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
How to read these results
- A bath and a swallowed supplement are different things. The cramp trials tested magnesium by mouth, so they say nothing about baths or oils. [4] The reverse is also true: a trial of baths does not show that magnesium entered the body.
- The bath trial compared baths with usual care, not with a plain bath, so warmth, rest and attention may explain some of the effect. That is an interpretation of the design, not something the authors reported. [2]
- A single small trial from one country is a reason for more research, not a reason to conclude that Epsom salt works.
- Full ingredient profiles: Epsom salt, Epsom salt baths for muscle soreness and sleep and Epsom salt versus magnesium supplements. For magnesium as a nutrient, see magnesium.
Safety, and who should ask first
- Heat after a new injury: the NHS advises avoiding heat such as hot baths and heat packs, as well as alcohol and massage, for the first couple of days after a sprain or strain. [5]
- Reduced skin sensation (for example diabetes nerve damage): that page covers burn and infection cautions. See hydrotherapy with diabetes, neuropathy and reduced sensation.
- Swallowing: see the warning above. Magnesium overload from laxatives has also been reported in people with normal kidney function. [6]
- Skin reactions: natural does not mean non-irritating. See patch testing natural ingredients.
- Pregnancy, breastfeeding, children, kidney or liver disease, medicines and surgery: these were not described for Epsom salt baths or magnesium oil in the sources we read. We make no claim either way. Ask a pharmacist or clinician, and see medication interactions.
- Pain you should not treat yourself: the NHS says to get help if an injury is very painful or getting worse, or if you cannot put any weight on it. [5] For a possible broken bone, the NHS lists a crack heard at the time, a changed shape, numbness, or cold, discolored skin as reasons for emergency care. [5] In the US, call 911 or go to an emergency department.
References
- Walker P, Parnell S, Dillon RC. Epsom Salt Ingestion Leading to Severe Hypermagnesemia Necessitating Dialysis. J Emerg Med. 2020;58(5):767-770. Case report. PubMed 32389435. Read 2026-10-23.
- Kumar V, Shyoran R, Pareek B, et al. Exploring the therapeutic potential of epsom salt bath on pain and intensity of knee osteoarthritis: Randomized controlled trial. J Educ Health Promot. 2025;14:462. PubMed 41334264. Read 2026-10-23.
- Grober U, Werner T, Vormann J, Kisters K. Myth or Reality-Transdermal Magnesium?. Nutrients. 2017;9(8):813. PubMed 28788060. Read 2026-10-23.
- Garrison SR, Korownyk CS, Kolber MR, et al. Magnesium for skeletal muscle cramps. Cochrane Database Syst Rev. 2020;(9):CD009402. PubMed 32956536. Read 2026-10-23.
- NHS. Sprains and strains. Read 2026-10-23.
- Bokhari SR, Siriki R, Teran FJ, Batuman V. Fatal Hypermagnesemia Due to Laxative Use. Am J Med Sci. 2018;355(4):390-395. Case report and literature review. PubMed 29661354. Read 2026-10-23.