Learn about stacking risks, absorption conflicts, and beneficial combinations. Every interaction is backed by research.
Supplements that interfere with each other's absorption.
Calcium significantly reduces iron absorption when taken together.
Green tea catechins (EGCG) significantly reduce non-heme iron absorption.
Long-term zinc supplementation can deplete copper levels.
Calcium may reduce zinc absorption when taken in large doses together.
Very high doses of calcium may reduce magnesium absorption.
Calcium supplements should be separated from iodine/thyroid-related supplements for best absorption.
Iron and zinc compete for absorption when taken together in supplement form.
High-dose magnesium supplements may reduce iron absorption when taken together.
St. John's Wort may reduce CoQ10 levels by inducing CYP enzymes that metabolize it.
St. John's Wort may increase vitamin D metabolism, potentially reducing its effectiveness.
Very high doses of preformed vitamin A (retinol) may interfere with vitamin D function.
Supplements that amplify the same physiological effect.
Both increase serotonin and combining them raises the risk of serotonin syndrome.
Both increase serotonin levels and combining them significantly raises the risk of serotonin synd...
Both increase serotonin activity and combining them raises the risk of serotonin syndrome.
Combining serotonin-boosting supplements increases risk of serotonin syndrome.
Both are serotonin precursors and combining them may excessively elevate serotonin.
Both have antiplatelet and blood-thinning properties that are additive when combined.
Nattokinase is a strong fibrinolytic enzyme and combined with omega-3 blood-thinning effects may ...
Nattokinase is a strong fibrinolytic enzyme; combined with ginkgo antiplatelet effects, bleeding ...
Nattokinase is a potent fibrinolytic enzyme and curcumin has antiplatelet activity; combining the...
Both have blood-thinning properties through different mechanisms; the combination may increase bl...
Both have blood-thinning properties that are additive when combined.
Both increase serotonergic activity and combining them may elevate serotonin excessively.
Both improve insulin sensitivity and the blood-sugar-lowering effect may be additive.
Both may improve insulin sensitivity and could produce additive blood-sugar-lowering effects.
Ashwagandha may increase thyroid hormone levels. Combining with iodine supplements could overstim...
Both lower blood sugar and the effect is additive.
Both lower blood sugar through different mechanisms.
Both lower blood sugar and the effect is additive, which may cause hypoglycemia.
Both may lower blood sugar and the combination could increase hypoglycemia risk.
Both promote sleep and relaxation; the combined sedative effect may be strong.
Both have blood-thinning properties that may be additive.
Both lower blood pressure through different mechanisms.
Both inhibit platelet aggregation and the blood-thinning effect may be additive.
Both lower blood pressure and the effect may be additive.
Nattokinase has strong fibrinolytic activity and vitamin E has mild antiplatelet effects; combine...
Both have mild anticoagulant effects that may be additive.
St. John's Wort may reduce melatonin effectiveness by increasing its metabolism.
Both have mild blood-thinning effects.
Both have mild anticoagulant properties that may be additive.
Both have antiplatelet effects that may be additive.
Both have mild blood-thinning effects that may add up.
Supplements that work better together.
Both support stress reduction and sleep quality through complementary mechanisms.
CoQ10 may offset potential mitochondrial side effects of berberine.
Both support cardiovascular health through complementary mechanisms.
Both support mitochondrial energy production and act as complementary antioxidants.
Often used together for joint health, with some evidence of additive benefit.
Vitamin A helps mobilize iron stores and improves iron status.
Iron is required for thyroid hormone synthesis, and iron deficiency impairs thyroid function.
L-theanine modulates the stimulant effects of caffeine, creating calm focus.
Both promote relaxation and sleep through complementary, gentle mechanisms.
Vitamin B6 may enhance magnesium absorption and cellular uptake.
Both support sleep quality through complementary mechanisms and are commonly combined.
Both support antioxidant defenses through complementary mechanisms.
Selenium and vitamin E work together as complementary antioxidants.
Selenium is essential for thyroid hormone metabolism and works synergistically with iodine.
Piperine from black pepper increases curcumin bioavailability by up to 2,000%.
B12 and folate work together in the methylation cycle and red blood cell formation.
Vitamin C significantly enhances non-heme iron absorption.
Vitamin C regenerates oxidized vitamin E, creating a synergistic antioxidant network.
Vitamin C is essential for collagen synthesis and enhances the effectiveness of collagen suppleme...
Vitamin K2 helps direct calcium (absorbed via vitamin D) into bones and away from arteries.
Magnesium is required for vitamin D activation and metabolism.
Vitamin D significantly enhances calcium absorption from the gut.
Zinc supports vitamin D receptor function and both are important for immune health.
Both support immune function through complementary mechanisms and are often combined for cold pre...
Quercetin acts as a zinc ionophore, helping transport zinc into cells.
Supplements that should be taken at different times.
Take calcium and iron at different times of day for optimal absorption.
Take green tea extract and iron supplements at least 2 hours apart.
Take calcium and zinc supplements at different times for optimal absorption of both.
High-dose magnesium and zinc may compete for absorption.
Take magnesium and iron supplements at different times of day for best absorption.
Very high-dose vitamin C may reduce vitamin B12 absorption.
Take zinc and copper at different times to prevent zinc from blocking copper absorption.