Magnesium chloride
Magnesium oil
Forms: Tablets, solutions and flakes; also sprays and "magnesium oil" for the skin. Other magnesium salts have their own cards.
Other esters and forms: Magnesium, Magnesium aspartate, Magnesium carbonate, Magnesium citrate, Magnesium gluconate, Magnesium glycinate (bisglycinate), Magnesium hydroxide, Magnesium L-threonate, Magnesium lactate, Magnesium malate, Magnesium orotate, Magnesium oxide, Magnesium sulfate (Epsom salt), Magnesium taurate
Water-soluble inorganic magnesium salt. In a comparison study it was absorbed as well as lactate and aspartate and far better than oxide.
Legal status: Sold freely as a supplement; some products are registered OTC medicines; not prohibited in sport.
What it gives
What people use it for and what the sources report. Strength is a general category from the literature: mild, clear or strong.
Purpose
Taken for cramps, sleep and recovery, and to replace magnesium lost in heavy sweat or with diuretics; sprays, "magnesium oil" and bath flakes are marketed for sore muscles. It corrects low magnesium; with normal levels, effects on cramps, sleep and performance are small or unproven.
What people seek and what studies show
Absorption of chloride matched lactate and aspartate and was clearly higher than oxide. A review found no support for meaningful magnesium uptake through the skin, and in 35 active people a magnesium gel on the thighs did not reduce soreness or muscle-damage markers after downhill running.
Effects
Evidence: Limited human data — some human studies, small or short
Sought effects by goal (as reported)
Possible side effects
Possible does not mean certain: whether they appear depends on dose, duration, individual response and monitoring. Below — what to watch for and how to notice it early.
1 possible side effect
level · how often it is reportedWhat the levels mean
Level: general category from the literature, not your personal risk
How often
- common
- reported often
- possible
- reported in some people
- rare
- reported occasionally
How to lower the risks
For 1 of 1 possible side effect there are specific ways to lower the chance: everyday measures, supplements and options a doctor may consider. No measure removes a risk completely.
Low-level side effects
How each option helps (2)
- Working with a doctor — Assesses persistent vomiting or severe belly pain (possible pancreatitis or gallstones) and adjusts prescribed GLP-1 treatment when nausea persists.
- Pancreatin + dimeticone (Pankreoflat) — May ease heaviness and gas after meals; can cause nausea or diarrhea. Not for pork or cow's milk protein allergy (anaphylaxis reported) or early acute pancreatitis.
Check-ups and blood tests
Which tests and check-ups to do and when. This is a guide — agree the exact schedule with a sports physician.
For women
For leg cramps in pregnancy, a Cochrane review found the magnesium trials conflicting; in pregnancy, discuss it with a doctor first.
Myth & fact
“Magnesium oil on sore muscles after training works better than tablets.”
A review found no reliable evidence that meaningful amounts pass through the skin, and in a placebo-controlled trial in active people a magnesium gel did not ease soreness after downhill running.
Combinations
No specific combination notes for this substance yet. The stack check still adds up side effects that several substances share.
Sources
Possible side effects by body system, combinations, how to lower the risks and which tests to do — free.
Open the stack check