Epsom Salts or magnesium supplements
Epsom Salts ** Magnesium *****
Try magnesium for: rheumatoid arthritis, inflammatory conditions, neuropathic pain(1),
menstrual cramps, migraines, chronic pain with obesity
Magnesium blocks pain receptors to lower how much you can feel, lowers the amount of inflammation pain messages sent from injuries, and lowers overall body inflammation.
Oral magnesium helps when you’re low, obese, or have a chronic illness. If you have enough magnesium already, more won’t help. Absorbing magnesium with Epsom Salts may help a LITTLE, right where you soak, but won’t raise your whole-body level of magnesium.
Oral magnesium is pretty safe - side effects from overdosing are usually with IV, and include flushing, low blood pressure, nausea, headaches, and weakness of body muscles and eye muscles, causing blurred vision.(2)
365 mg - 500mg provided as magnesium citrate, gluconate or aspartate twice a day for
adults, with one case report maxing out at 1166mg/day of magnesium sulfate https://www.ncbi.nlm.nih.gov/pubmed/11847944
As people try to find non-drug solutions for pain, lots of old treatments are getting dusted off with fresh press. Epsom Salt baths, yoga, that kind of thing. The question is, what do doctors really recommend?
Here is a secret about medicine: most recommendations we doctors give are intensely well-researched evidence everyone agrees on. Some recommended therapies are fads, and a few recommendations are just passed along from teaching physicians to students without doctors even agreeing what they mean. Often these recommendations are delivered with the same confidence.
For example, “sitz baths” – you might get this recommended for an abscess, ingrown toenail, or “nether region” complaint. Turns out there isn’t much agreement even in the medical literature about what this means, beyond plopping the affected area in a shallow tub. Instructions are often given to take a “sitz bath”, but different practitioners may mean with baking soda, plain water, or Epsom salts. The original therapeutic baths contained Epsom salts, from magnesium rich deposits in a town south of London.
While the research on Epsom soaks is muddied with other-ingredient sitz baths studies, a growing body of literature supports that magnesium has several ways it relieves pain.
Smooth muscles live in your body’s tubes - blood vessels, airways, uterus, that kind of thing. Magnesium in high doses has been used for decades in emergency departments to relax tight, asthmatic airways. Turns out magnesium is also good for migraine headaches, and has brain-protective effects as well. While relaxing skeletal neck muscles to reduce a headache makes sense, the impact on smooth muscles by blocking calcium channels may be part of how magnesium relieves body pains. Several German studies in the early 90’s found magnesium to help menstrual cramping - totally makes sense.
Ok, strap in for some SCIENCE (physiology to be exact). Pain stimulates receptors in nerve cells called N-methyl-D-aspartate (NMDA) receptors. One of the reasons opioids are addictive is that when they are used to block pain, the NMDA receptors can overcompensate just to make sure you’re getting all the pain you’re entitled to. You then need more opioids over time to get the same effect (tolerance) which makes opioids a bad choice for chronic pain. Here’s the cool thing: magnesium acts as a blocker of an NMDA subunit. It can decrease pain some on its own, but seems REALLY good at making a small dose of opioid go farther for pain relief.
Magnesium impacts cells’ ability to create the pain messages that get sent out in the first place. These messages are sent in the form of molecules called “inflammatory cytokines”. When tissues are inflamed, they let the world know with cytokines. These molecules are related to acute pain, but when you keep cranking them out, the body’s immune system gets revved up which causes more damage. Magnesium supplementation worked at reducing inflammation for people whose baseline inflammation was high, as measured with a test called a CRP. Normal CRPs are around 1, and taking extra mag didn’t do anything for them. For people who had CRP levels over 3 (ie. Most people with rheumatoid arthritis) taking extra magnesium DID lower CRP. Lower whole body inflammation, less pain.
Babies born to women who got magnesium IV to slow labor (by relaxing smooth muscles in the uterus) seem to have less brain damage. By extrapolation, look to see new concussion studies testing magnesium, and magnesium for athletes.
All this is great, but the question was whether Epsom salt baths do diddly. When you’re low on magnesium, taking more likely makes lots of stuff gets better. Whether people can absorb magnesium in through the skin while soaking in it is a different matter. Previous skeptical exposes denied that Epsom baths raised whole body magnesium levels. On the one hand, these studies didn’t have patients soaking areas that might absorb better (um, reference “nether regions” above), and certainly they weren’t going London Old School and soaking for hours at a time. More recent research shows magnesium is absorbed, particularly well through hairy areas. This means there may be local benefits, for your ingrown toenail or inflamed abscess. Proving the point, randomized controlled trials of magnesium-rich mud worked better for hand arthritis than mud-applied-on-top-of-gloves where nothing could be absorbed.
Epsom salt baths were all the rage at various times and places in medical history. For now, it makes sense that if you’re bothering to soak, adding magnesium rich Epsom salt can’t hurt, but hedge your bets and take some orally if you might be low. Finally, though, here’s another doctor secret: sometimes fads become well researched medicine.
1. Urits I, et al. Utilization of Magnesium for the treatment of Chronic Pain. Anesth Pain Med 2021 Feb 6;11(1):e112348.
2. Bujalska M et al. Magnesium enhances opioid-induced analgesia – what have we learnt in the past decades. Eur J Pharm Sci. 2017 Mar 1;99:113-127.
3. Bujalska M, Makulska-Nowak H, Gumulka SW. Magnesium ions and opioid agonists in vincristine-induced neuropathy. Pharmacol Rep2009;61:1096–104.
4. Bain ES, Middleton PF, Crowther CA. Maternal adverse effects of different antenatal magnesium sulphate regimens for improving maternal and infant outcomes: a systematic review. BMC Pregnancy Childbirth. 2013 Oct 21;13:195
5. Yousef AA A double-blinded randomised controlled study of the value of sequential intravenous and oral magnesium therapy in patients with chronic low back pain with a neuropathic component. Anaesthesia. 2013 Mar;68(3):260-6.
6. Banerjee S, Jones S. Magnesium as an alternative or adjunct to opioids for mibraine and chronic pain:
A review of the clninical effectiveness and guidelines. Canadian Agnecy for drugs and technologies in health; 2017 Ap 20. PMID 29334449
7. Fioravanti A, et al. One year followup of mud-bath therapy in patients with bilateral knee OA: randomized, single blind controlled trial. Int J Biometeorol. 2015 Sep;59(9):1333-43
8. Vujovic synergy ketamine and magnesium sulphate nociception rats. Eru Rev Med Pharmacol Sci.
2015Jul;19:2503 https://www.ncbi.nlm.nih.gov/pubmed/26214789
9. Simental-Mendia L, et al. Effect of magnesium supplementation on plasma C-reactive protein concentrations: A systematic review and meta-analysis of randomized controlled trials. Curr Pharm Des. 2017;23(31):4678-4686