In short: Yes, in small amounts. Lab studies show that magnesium from oil or magnesium spray penetrates the outermost layer of skin, mostly through the hair follicles. In one study, blood levels rose after two weeks of using a magnesium cream. Magnesium oil and a magnesium bath are a pleasant addition after exercise, for dry skin, or as part of an evening routine. You cover your daily needs most reliably through food and supplements.
Key points
- Magnesium oil isn't actually an oil: it's a concentrated solution of magnesium chloride and water that only feels oily on skin.
- Skin lets some through: magnesium penetrates the upper layer of skin, mostly via the hair follicles. How much reaches the blood varies from person to person.
- Good results in small studies: women with chronic muscle pain (fibromyalgia) felt better after four weeks of spray. A salt bath rich in magnesium made dry skin smoother and more hydrated.
- The warm bath itself counts too: a warm bath or foot bath in the evening helps with falling asleep in studies, with or without salt.
- Well tolerated: no side effects turned up in the studies. Even so, the oil doesn't belong on broken or freshly shaved skin.
Contents
- What is magnesium oil?
- Does skin absorb magnesium?
- Magnesium oil and spray: what do users report, what do studies show?
- Magnesium bath and Epsom salt bath: what does it do?
- How to use magnesium oil correctly
- Through the skin or taken by mouth?
- Is magnesium oil well tolerated?
- Frequently asked questions
- Limits of the research and all sources
What is magnesium oil?
Magnesium oil is a highly concentrated salt solution: magnesium chloride, dissolved in water. It gets its name because it feels smooth and slightly oily on skin. There's no fat or oil in it at all.1
The magnesium chloride often comes from ancient salt deposits such as the Zechstein, a layer of rock beneath northern Germany and the Netherlands, or from the Dead Sea. As a spray, it's easy to apply. The same solution also comes thickened as a gel, or mixed with fats as a cream.
| Product | What's in it | Typical use |
|---|---|---|
| Magnesium oil, magnesium spray | Magnesium chloride in water | spray on, massage in |
| Magnesium gel, magnesium cream | Magnesium chloride with a gel or cream base | rub in, absorbs more slowly |
| Magnesium flakes | Magnesium chloride as flakes (hexahydrate) | full or foot bath, also for making your own oil |
| Epsom salt | Magnesium sulfate (heptahydrate) | full or foot bath |
| Dead Sea salt | Salt mix rich in magnesium chloride | full bath |
What the studies show: many manufacturers recommend 5 to 30 sprays a day, which works out to 75 to 400 mg of magnesium depending on the product. Many bottles, though, don't state how much magnesium the solution actually contains.2 In one study, 20 sprays a day delivered 150 mg of magnesium onto the skin, so around 7.5 mg per spray (our calculation from the study's figures).3
Does skin absorb magnesium?
Yes, some of it. Magnesium can get through the outermost layer of skin. The easiest route in is via the hair follicles. The higher the concentration and the longer the solution stays on the skin, the more gets through. So let oil or spray sit for a few minutes instead of washing it straight off, and apply it to areas with fine hairs, such as arms, legs or your stomach.
What the studies show: on human skin in the lab, magnesium penetrated more strongly the more concentrated the solution was and the longer it was left on. The hair follicles contributed clearly to this.4 In a British study, 25 adults applied a cream with either 56 mg of magnesium or no magnesium daily for two weeks. In the magnesium group, blood levels rose from 0.82 to 0.89 mmol/L, while the comparison group barely changed. The rise was statistically clear only in participants who weren't competitive athletes.2
Hospitals also test the skin as a route, specifically in people who absorb magnesium poorly through the gut. Six patients with a stoma and low magnesium levels sprayed 150 mg onto their skin daily for six weeks. In two of them, blood levels rose, and one patient avoided her planned magnesium infusion.3 In 21 kidney transplant recipients, magnesium levels also rose after two months of using a magnesium gel.5
Our take: skin does absorb magnesium, just less reliably than the gut, and it varies a lot by person and product. That makes magnesium oil and magnesium baths a good addition, for example on your legs after exercise or as part of your evening routine. You're best off securing your baseline needs through food and, if needed, magnesium taken by mouth. Exactly how much gets through via the skin is something larger studies still need to clarify.
Magnesium oil and spray: what do users report, what do studies show?
Many people use magnesium oil for their muscles: on calves and thighs in the evening, after training, or after a long day on their feet. Others value massaging it in as a calming ritual before bed. Early studies with positive results exist for exactly these situations.
What the studies show: at the Mayo Clinic in the US, women with fibromyalgia, a chronic pain condition, sprayed magnesium chloride onto their arms and legs twice daily for four weeks. The 24 women who completed the study rated their symptoms and daily functioning noticeably better after just two weeks.6 In the study with gut patients, all six reported muscle cramps at the start. After three weeks, five of them reported that the cramps had eased or gone away completely.3
The skin itself benefits too. At the university dermatology clinic in Kiel, volunteers with dry, eczema-prone skin bathed one forearm for 15 minutes in salt water. The solution contained 5% Dead Sea salt, which is rich in magnesium chloride. The other arm went into tap water. Over six weeks, the skin on the salt-water arm became more hydrated, smoother and less red.7
Magnesium bath and Epsom salt bath: what does it do?
A magnesium bath combines two things: warm water and magnesium salt. The warm water alone already does something for you: a full bath or foot bath in the evening can make it easier to fall asleep. The salt turns it into a small ritual. For a full bath, you use magnesium flakes (magnesium chloride) or Epsom salt (magnesium sulfate); the amount is on the packaging.
What the studies show: an analysis of 13 studies found better sleep quality after a warm bath or shower. The best results came at 40 to 42.5°C, one to two hours before bed. Even ten minutes shortened the time it took to fall asleep.8 Warm foot baths also improved perceived sleep quality across 18 studies involving 950 older people, best with a temperature of no more than 40°C and at least ten minutes.9
How to do it:
- Full bath: add salt to the running water as directed on the packaging, at around 40°C, for 10 to 20 minutes, one to two hours before bed.
- Foot bath: a bowl of warm water, a handful of flakes or Epsom salt, at least 10 minutes. Handy if you don't have a bathtub.
- Afterwards: rinse off briefly or towel dry, and moisturise if your skin tends to be dry.
How much magnesium is in the salt? 100 g of Epsom salt contains around 10 g of magnesium, and 100 g of magnesium flakes around 12 g (our calculation from the molar masses).10, 11 That's many times your daily requirement. Through the skin, though, only a small part of that actually reaches your body.
You can read more about warm baths, magnesium and falling asleep in our article Magnesium for sleep.
How to use magnesium oil correctly
Spray the oil onto clean, dry skin and massage it in. Calves, thighs, arms and your stomach work well. Let it sit until it's absorbed. A light salty film is normal, and you can wash it off later.
How to do it:
- Amount: start with a few sprays and build up as directed on the packaging. Check whether the bottle states how much magnesium each spray delivers.
- Timing: in the evening after a shower or after exercise, so you can let it absorb undisturbed.
- Avoid: freshly shaved, broken or irritated skin, mucous membranes and eyes.
- Does it tingle? Then the solution is too strong for your skin. Wash it off and dilute it with a little water next time.
What the studies show: most studies applied 4 to 5 sprays per arm or leg, once or twice a day. One study used 10 sprays twice a day on the torso, upper arms and thighs.3, 6, 12 Magnesium penetrated the skin more strongly the longer it was left on.4
Making your own magnesium oil: many people mix magnesium flakes and warm, boiled water in equal parts. 100 g of flakes in 100 ml of water gives a solution of around 6% magnesium by weight (our calculation from the molar mass).10 Keep it in a clean spray bottle.
Through the skin or taken by mouth?
Both routes have their place. Magnesium taken by mouth is well studied and easy to dose precisely. Magnesium oil and baths are a pleasant addition, especially where you want to feel something: on legs and feet, after exercise, or in the evening.
| Magnesium by mouth | Magnesium oil, spray, bath | |
|---|---|---|
| Absorption | well studied, predictable | small amounts, varies by person |
| Dosing | precise, in mg per serving | imprecise, often not stated |
| Stomach and gut | large amounts can cause loose stools | no contact with the gut |
| Especially suited to | supply across the day | legs, feet, skin, evening ritual |
For magnesium from food, official claims are approved in the EU. Two examples:
- Magnesium contributes to normal muscle function.
- Magnesium contributes to a reduction of tiredness and fatigue.
These claims apply to magnesium you eat or take as a supplement, not to oils, sprays or baths. How much magnesium you actually need is covered in our article How much magnesium per day? How the gut absorbs magnesium is explained in How is magnesium absorbed by the body? For an overview of everything magnesium does in your body, see Magnesium benefits.
Is magnesium oil well tolerated?
Yes. In the studies using cream and spray, nobody reported side effects.2, 3 Because only a small amount of magnesium gets through the skin, too much from oil or a bath isn't expected in people with healthy kidneys. What's more common is something quite different: the salty solution can tingle, itch or feel drying on sensitive skin.
What the studies show: on pig skin in the lab, barely any magnesium came through intact skin. Once the outermost skin layer was removed beforehand, it was many times more.13 Damaged skin, in other words, lets through significantly more. That's why oil and salt baths don't belong on broken skin.
Important: magnesium oil, flakes and Epsom salt are for skin use only. Don't drink them, keep them out of your eyes, and store them out of children's reach. If you have kidney disease, large areas of damaged skin, or a skin condition, talk to your doctor before taking regular magnesium baths. What happens with too much magnesium in the blood is covered in Too much magnesium.
Frequently asked questions
How quickly does magnesium oil work? You'll feel the sensation on your skin and the massage straight away. In the studies, changes in symptoms and blood levels showed up after two to six weeks of regular use.2, 3, 6
Can you use magnesium oil every day? Yes. In the studies, it was applied once or twice daily, over two to twelve weeks.2, 3, 6, 12 Where side effects were asked about, none turned up.2, 3
Magnesium spray on your feet: does that help? Feet are popular because they're easy to reach in the evening. For absorption, though, areas with fine hairs are better suited, such as calves or forearms, because magnesium mostly gets in via the hair follicles.4 If you want to treat your feet, a warm foot bath with flakes is the way to go: the foot bath itself improved sleep quality in studies.9
Why does magnesium oil sting or itch? Magnesium oil is a very salty solution. On dry, irritated or freshly shaved skin, that can tingle. Dilute the oil with water, apply it somewhere else, or wash it off after a few minutes.
Can too much magnesium cause skin redness? Skin redness (flushing) is one of the signs when blood magnesium is very highly elevated, above 3.5 mmol/L. That happens almost only with severe kidney impairment combined with a lot of magnesium intake.14 Through oil or a bath, that's not expected in people with healthy kidneys. Redness right where you sprayed is a different thing: a local irritation from the salt.
Is Epsom salt in the bath the same as Epsom salt you drink? It's the same substance, magnesium sulfate. In the bath, it only works via the skin. Taken by mouth, Epsom salt has a strong laxative effect, so never drink your bath salt. You can read more about the different forms of magnesium in Which magnesium is best?
Limits of the research and all sources
The studies on magnesium through the skin are small, short, and often without a comparison group. A 2017 review concluded that skin absorption is not sufficiently supported by science.15 Commonly cited evidence is weak: a study of nine people that only measured hair samples, and a never-published report on 19 people in an Epsom salt bath.15 In the cream study, the rise wasn't statistically significant when calculated across all participants.2 On pig skin in the lab, barely any more magnesium came through intact skin than with no treatment at all.13 A magnesium gel didn't ease muscle soreness after downhill running in 35 athletes any more than a gel without magnesium.16 In people with advanced kidney disease, blood levels stayed unchanged under a magnesium spray.12 The positive studies on fibromyalgia, cramps and kidney transplant recipients had no control group, or no blinded one.3, 5, 6 The gut study was supported by the manufacturer of the spray used.3 The skin bath in the Kiel study contained Dead Sea salt, so other minerals alongside magnesium.7 The sleep studies looked at warm water, not the salt.8, 9
▸ Show all 16 studies and sources
| # | Study | Who was studied | Result | Strength of evidence |
|---|---|---|---|---|
| 1 | Werner et al. 2017, Trace Elem Electrolytes | Review | Magnesium oil is a concentrated magnesium chloride solution, not an oil | Review |
| 2 | Kass et al. 2017, PLoS One | 25 adults, 56 mg magnesium as cream, 2 weeks | Blood level 0.82 → 0.89 mmol/L, statistically clear only in non-athletes; no side effects; commercial products 75–400 mg | small controlled pilot study, single-blind; no funding stated, one author with a later interest in another cream |
| 3 | Nightingale et al. 2024, Intestinal Failure | 6 patients with an ileostomy and low magnesium, 150 mg spray, 6 weeks | Blood level rose in 2, 1 infusion avoided, cramps improved in 5, no side effects | very small, no control group; spray and lab costs from the manufacturer |
| 4 | Chandrasekaran et al. 2016, Magnes Res | human skin in the lab | Magnesium penetrates, depending on concentration and time, mainly via hair follicles | Lab study |
| 5 | Moisa et al. 2026, Nutrients | 21 kidney transplant recipients, magnesium gel, 2 months | Blood level rose, well tolerated | small study, no control group |
| 6 | Engen et al. 2015, J Integr Med | 40 women with fibromyalgia (24 completed), spray, 4 weeks | Symptoms and quality of life clearly better by questionnaire | feasibility study, no control group |
| 7 | Proksch et al. 2005, Int J Dermatol | volunteers with dry, atopic skin, forearm bath 5% Dead Sea salt, 6 weeks | Skin more hydrated, smoother, less red than the water-only arm | small controlled study (arm vs arm); salt from one manufacturer, funding not stated |
| 8 | Haghayegh et al. 2019, Sleep Med Rev | 17 studies, 13 analysed | warm bath/shower 40–42.5°C, 1–2 h before bed: better sleep, faster sleep onset | Meta-analysis |
| 9 | Chang et al. 2025, Scand J Caring Sci | 18 studies, 950 older adults | warm foot bath improves perceived sleep quality | Meta-analysis |
| 10 | PubChem CID 24644 | Substance database | Magnesium chloride hexahydrate 203.30 g/mol → 12.0% magnesium | Reference data |
| 11 | PubChem CID 24843 | Substance database | Magnesium sulfate heptahydrate 246.48 g/mol → 9.9% magnesium | Reference data |
| 12 | Athavale et al. 2023, J Palliat Med | 20 people with advanced kidney disease, spray, 12 weeks | Blood level unchanged, symptoms lower by questionnaire | small study, no control group |
| 13 | Camili et al. 2026, Eur J Pharm Biopharm | pig skin in the lab, magnesium sulfate | intact skin: barely any passage; damaged skin: many times more | Lab study |
| 14 | Aalhamad et al. 2023, Medicina | Review | skin flushing from blood levels above 3.5 mmol/L | Review |
| 15 | Gröber et al. 2017, Nutrients | Review | skin absorption not sufficiently supported by science; assesses a hair-sample study (9 people) and an unpublished Epsom salt bath report (19 people) | Review |
| 16 | Coates et al. 2025, Int J Sport Nutr Exerc Metab | 35 athletes, magnesium gel vs placebo gel | no difference in muscle soreness | Controlled study |
Author: PRONESIUM Editorial Team · Last reviewed: 30/09/2026 · This article does not replace medical advice.
