Skip to content
What Causes What
MECHANISM? CONDITIONAL

Magnesium supplementation → Insulin resistance (HOMA-IR)

Higher Magnesium supplementation moves Insulin resistance (HOMA-IR) only in some conditions. Read the mechanism.

Drenthen 2024 found that 15 mmol a day of oral magnesium for six weeks did not change clamp insulin sensitivity versus placebo in 14 adults with insulin-treated type 2 diabetes (M value 4.6 versus 4.4). An intensive-care loading dose then moved HOMA in stress hyperglycemia (Heidary 2021).

Randomized trial · Contested · N=14

Supported by an experiment or a tightly identified design. Read the caveats.

Mechanism

Authors treat magnesium as a cofactor in insulin signaling. Raising a low serum number is supposed to make insulin work better. The gold-standard test of that claim is a clamp, not a HOMA worksheet. Drenthen, de Baaij, Rodwell and colleagues (2024) assigned 14 White adults with insulin-treated type 2 diabetes and serum magnesium at or below 0.79 mmol per liter to 15 mmol a day of oral magnesium or matched placebo for six weeks each, in a blinded crossover. Serum and urine magnesium rose on the salt. The clamp M value was 4.6 versus 4.4 mg per kg per minute (P=0.108). Heidary, Khalili, Mohammadi, Beigmohammadi and Abdollahi (2021) assigned 70 critically ill people with stress hyperglycemia and no diabetes to 7.5 g of intravenous magnesium sulfate over eight hours or placebo. By day 3, HOMA change was -0.11 versus placebo (95 percent CI -0.19 to -0.01). Adiponectin rose. Shahmoradi, Chiti, Tavakolizadeh and colleagues (2024) assigned 40 women aged 15 to 35 with PCOS to 250 mg a day of magnesium oxide or placebo for two months. Serum insulin (P=0.036) and insulin resistance (P=0.032) fell in the magnesium arm. Sadeghian, Azadbakht, Khalili and colleagues (2020) assigned 80 people with type 2 diabetes, early nephropathy, and low serum magnesium to daily magnesium oxide or placebo for twelve weeks. Insulin resistance was higher on magnesium than on placebo (P=0.04). Rodríguez-Morán, Simental-Mendía, Gamboa-Gómez and Guerrero-Romero (2019) assigned 198 people with metabolic syndrome and serum magnesium under 1.8 mg per deciliter to 382 mg of elemental magnesium as chloride or placebo for sixteen weeks. Fasting glucose fell 12.4 mg per deciliter more on magnesium.

Caveats

Researchers assigned people to a salt or a control, so this is a trial stamp. The only clamp is fourteen people and a null. More papers of the same design do not settle the claim. Drenthen is insulin-treated type 2 diabetes, six weeks, a crossover. Serum magnesium rose. Sensitivity did not. Heidary is an intensive-care load, not a daily oral salt, and not diabetes. HOMA moved. A clamp did not. Shahmoradi is PCOS and no published HOMA increment. Sadeghian is diabetic kidney disease and the insulin-resistance change went the other way. Rodríguez-Morán identifies fasting glucose, not HOMA-IR. This is a journal entry, not medical advice and not a reason to start or stop a salt.

Effect

qualitative. Drenthen 2024 clamp M 4.6 vs 4.4, P=0.108, N=14. Heidary 2021 ICU load, HOMA -0.11 vs placebo, N=70. Shahmoradi PCOS IR down. Sadeghian nephropathy IR up.

Nodes

Lifestyle & environmentMagnesium supplementationBiology & endocrinologyInsulin resistance (HOMA-IR)

Named confounders

Cite this page

What Causes What. “Magnesium supplementation → Insulin resistance (HOMA-IR).” https://whatcauseswhat.org/edges/e-magnesium-insulin (atlas updated 2026-09-02).

https://whatcauseswhat.org/edges/e-magnesium-insulin

Papers