Magnesium gluconate
Forms: Tablets and liquids. Other magnesium salts have their own cards.
Other esters and forms: Magnesium, Magnesium aspartate, Magnesium carbonate, Magnesium chloride, Magnesium citrate, Magnesium glycinate (bisglycinate), Magnesium hydroxide, Magnesium L-threonate, Magnesium lactate, Magnesium malate, Magnesium orotate, Magnesium oxide, Magnesium sulfate (Epsom salt), Magnesium taurate
Magnesium salt of gluconic acid. In magnesium-depleted rats it was the best absorbed of ten salts; direct comparisons in humans are lacking.
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
Athletes take it for cramps, sleep and recovery, and to replace magnesium lost in heavy sweat, with diuretics or on low-food diets in weight-class sports. It corrects low magnesium; with normal levels, effects on cramps, sleep and performance are small or unproven.
What people seek and what studies show
In magnesium-depleted rats gluconate was the best absorbed of ten salts; there are no head-to-head human trials. In endurance athletes, blood magnesium dropped after a 90-minute ergometer ride and returned to baseline within about 2.5 hours, so the timing of a test matters. With adequate magnesium, supplements have not improved performance.
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
“Cramps in training or a race mean you are low on magnesium.”
In 72 ultra-distance runners, those who cramped had no clinically meaningful electrolyte or hydration changes, and their blood magnesium after the race was not lower. A Cochrane review found no trials of magnesium for exercise cramps.
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