Table of Contents
Table of Contents
Despite its name, magnesium oil is not an oil. It is magnesium chloride dissolved in water, creating a slippery solution that can be sprayed or rubbed onto the skin or added to bathwater.
Whether magnesium is absorbed from the skin in nutritionally meaningful amounts remains unresolved. In a 2017 pilot study, 25 healthy adults applied a magnesium cream or placebo daily for two weeks. Serum and urinary magnesium increased more in the magnesium group, but the between-group difference was not statistically significant.1 The skin's outermost layer, the stratum corneum, is designed to restrict the passage of water-soluble substances, including magnesium ions. Hair follicles have been proposed as an alternate route, but this has not been established as a clinically meaningful pathway in humans.
No evidence-based study has established a health benefit from topical magnesium application. The NIH tolerable upper intake level of 350 mg daily applies to magnesium from oral supplements and medications, not topical products.2 The 2017 absorption pilot used a cream providing 56 mg of magnesium daily.1 A practical approach is to follow the product directions or apply a light layer once daily at first, then reduce the concentration or frequency if irritation occurs.
Topical products may appeal to people who dislike pills or experience diarrhea or stomach upset from oral magnesium. However, oral magnesium has a much stronger evidence base for boosting magnesium intake because its absorption and dosing are well-established. There is no data that supports that enough magnesium reaches the circulation when applied to the skin to improve magnesium status.
Magnesium oil is commonly massaged into sore or tense muscles. In a small 2015 feasibility study, 40 women with muscular discomfort were instructed to apply magnesium chloride spray to their arms and legs twice daily for four weeks. Only 24 completed the study, and symptom scores improved from baseline.3 Because the study was open-label and had no placebo group, the improvement cannot be separated from a placebo effect, massage, natural symptom fluctuation, or other influences. Products sometimes combine magnesium with ingredients such as arnica, but the combination also lacks any clinical-trial evidence.
Some people add topical magnesium to their bedtime routine. Although oral magnesium has been studied for sleep, no placebo-controlled trial has established that topical magnesium improves sleep or relaxation.
Magnesium sprays and products called magnesium oil are generally water-based magnesium chloride solutions. Creams and lotions add an emollient base that may feel more comfortable on dry or sensitive skin. No clinical evidence shows that one topical format is absorbed better than another, so the choice primarily comes down to comfort and convenience. Magnesium flakes, used as a bath soak rather than applied directly to the skin, are a related but separate product covered in more detail in iHerb's dedicated guide to magnesium flakes.
Topical magnesium has not been adequately studied in children. Parents should consult a pediatrician before use, choose an unscented product when possible, perform a small patch test, and apply it only to intact skin.
Bring 1/2 cup of distilled water to a boil. Pour it over 1/2 cup of magnesium chloride flakes, stir until dissolved, cool completely, and transfer the solution to a clean spray bottle. Magnesium sulfate, or Epsom salt, is a different compound and is not a direct substitute in this recipe. Essential oils like lavender or eucalyptus oil are optional, but they can irritate sensitive skin and should be omitted from products intended for children.
Common application areas include the shoulders, neck, upper back, forearms, and legs. Test a small area first, especially if you have sensitive skin, and avoid the face, freshly shaved skin, rashes, cuts, and other irritated areas. If tingling or burning is bothersome, rinse the product off and use a more dilute solution next time. Persistent irritation is a reason to stop using it. Stinging most likely reflects the irritating effect of a concentrated magnesium chloride solution on the skin; it is not a validated measure of magnesium deficiency.
Because absorption through the skin appears to be limited and inconsistent based on the available pilot data, topical magnesium is generally considered lower-risk than oral supplementation for most healthy adults. A few precautions still apply:
Possibly in small amounts, but meaningful systemic absorption has not been demonstrated convincingly. The only controlled human pilot found no statistically significant serum or urinary benefit in the full study population.1
Some users find it soothing, but the only relevant magnesium-spray study was small, uncontrolled, and conducted in women experiencing widespread muscular discomfort.3 Massage and expectancy effects may contribute to the perceived benefit. Evidence for oral magnesium in ordinary skeletal muscle cramps is also limited.4
Usually, there is no meaningful difference. "Oil" describes the solution's slippery feel, while "spray" describes the dispenser. Concentrations and added ingredients can vary, so check the label.
It is generally well tolerated on intact skin. The most common complaint is temporary stinging, tingling, or itching, especially on dry, freshly shaved, or irritated skin. This sensation does not indicate the severity of magnesium deficiency.
Apply a light layer to intact skin and massage it in. Follow the manufacturer's directions, and rinse it off if irritation develops. No research has established an optimal application site, timing, or duration.
They're generally the same product; "magnesium oil" describes the slightly oily feel of a magnesium chloride and water solution, while "spray" describes how it's typically packaged and applied. Some products labeled "magnesium spray" use a slightly different concentration or added ingredients, so checking the label is worthwhile if a specific use case matters to you.
Magnesium oil and spray are inexpensive topical magnesium chloride products commonly used for muscle soreness, tension, and relaxation. They may feel soothing, but evidence for meaningful absorption through the skin or specific clinical benefits remains weak. Healthy adults can reasonably try them with appropriate skin precautions, but topical magnesium should not be presented as equivalent to oral supplementation for correcting inadequate magnesium intake. For oral magnesium's much more extensively studied effects on sleep, relaxation, and brain health, see iHerb's dedicated guides on those topics. Browse iHerb's full range of magnesium supplements to find a form that fits your routine.
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DISCLAIMER: These statements have not been approved by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent disease.
