# StackingRight > StackingRight is a supplement and nutrient interaction checker and dosing > schedule builder. It maps duplicate nutrients across a stack, nutrient-drug > conflicts, absorption competition and synergies, then places every item into > a timed daily schedule. Every interaction rule cites an authoritative source. StackingRight is a decision-support tool, not medical advice. It is intended for educational use and for preparing questions for a physician or pharmacist. ## Key pages - [Home](https://stackingright.app/): product overview, live stack demo and pricing - [Interaction checker](https://stackingright.app/tools/interaction-checker): free, no signup, pick two or more supplements and see flagged interactions - [RDA calculator](https://stackingright.app/tools/rda-calculator): nutrient targets against RDA and upper intake levels - [Timing planner](https://stackingright.app/tools/timing-planner): assigns each supplement a window and with-or-without-food instruction - [Library](https://stackingright.app/library): nutrient and supplement encyclopedia - [Guides](https://stackingright.app/guides): long-form protocols and interaction explainers - [Methodology](https://stackingright.app/methodology): how rules are sourced and how the score is computed - [Pricing](https://stackingright.app/pricing) ## Nutrient reference pages - [Vitamin D3](https://stackingright.app/library/vitamin-d3): Regulates calcium absorption and bone mineralisation, and supports immune and neuromuscular function. - [Vitamin K2](https://stackingright.app/library/vitamin-k2): Directs calcium into bone and away from arteries by activating osteocalcin and matrix Gla protein. - [Vitamin K1](https://stackingright.app/library/vitamin-k1): The plant form of vitamin K, essential for clotting factor synthesis. - [Vitamin A](https://stackingright.app/library/vitamin-a): Supports vision, immune defence and skin integrity; required for gene transcription. - [Vitamin E](https://stackingright.app/library/vitamin-e): Chain-breaking antioxidant that protects cell membranes from lipid peroxidation. - [Vitamin C](https://stackingright.app/library/vitamin-c): Water-soluble antioxidant and cofactor for collagen synthesis; sharply increases non-heme iron absorption. - [Thiamin](https://stackingright.app/library/vitamin-b1): Cofactor for carbohydrate metabolism and nerve conduction. - [Riboflavin](https://stackingright.app/library/vitamin-b2): Electron carrier in energy production and a cofactor for glutathione recycling. - [Niacin](https://stackingright.app/library/vitamin-b3): Supports NAD/NADP-dependent energy metabolism and DNA repair. - [Pantothenic acid](https://stackingright.app/library/vitamin-b5): Precursor to coenzyme A, central to fatty-acid metabolism. - [Vitamin B6](https://stackingright.app/library/vitamin-b6): Cofactor for neurotransmitter synthesis and haemoglobin formation. - [Biotin](https://stackingright.app/library/vitamin-b7): Cofactor for carboxylase enzymes in fat, glucose and amino-acid metabolism. - [Folate](https://stackingright.app/library/vitamin-b9): One-carbon metabolism for DNA synthesis and red blood cell production. - [Vitamin B12](https://stackingright.app/library/vitamin-b12): Required for myelin maintenance and red blood cell formation. - [Choline](https://stackingright.app/library/choline): Precursor to acetylcholine and phosphatidylcholine; supports liver and cell-membrane function. - [Calcium](https://stackingright.app/library/calcium): Primary structural mineral in bone and a signalling ion in muscle and nerve function. - [Magnesium](https://stackingright.app/library/magnesium): Cofactor in 300+ enzyme reactions including ATP handling, and a natural calcium channel blocker. - [Zinc](https://stackingright.app/library/zinc): Cofactor for immune signalling, wound healing and hundreds of zinc-finger transcription factors. - [Iron](https://stackingright.app/library/iron): Carries oxygen in haemoglobin and supports mitochondrial electron transport. - [Copper](https://stackingright.app/library/copper): Cofactor for cytochrome c oxidase, superoxide dismutase and copper-dependent collagen cross-linking. - [Selenium](https://stackingright.app/library/selenium): Incorporated into selenoproteins including glutathione peroxidase and thyroid deiodinases. - [Iodine](https://stackingright.app/library/iodine): Substrate for thyroid hormone synthesis. - [Chromium](https://stackingright.app/library/chromium): Potentiates insulin signalling; evidence for meaningful glucose effects is mixed. - [Manganese](https://stackingright.app/library/manganese): Cofactor for manganese superoxide dismutase and arginase. - [Potassium](https://stackingright.app/library/potassium): Principal intracellular cation; sets resting membrane potential and blood pressure. - [Omega-3](https://stackingright.app/library/omega-3): Precursors to resolvins and protectins; supports membrane fluidity and cardiovascular function. - [CoQ10](https://stackingright.app/library/coq10): Electron carrier in mitochondrial respiration and a lipid-phase antioxidant. - [Glutathione](https://stackingright.app/library/glutathione): Master intracellular antioxidant and cofactor for phase II detoxification. - [Curcumin](https://stackingright.app/library/curcumin): Polyphenol that modulates NF-kB inflammatory signalling. - [Quercetin](https://stackingright.app/library/quercetin): Flavonol with antihistamine and senolytic activity in vitro. - [Inositol](https://stackingright.app/library/inositol): Second messenger precursor involved in insulin signalling and ovarian function. ## Guides - [Magnesium Glycinate: Dose, Timing and Interactions](https://stackingright.app/guides/magnesium-glycinate): The best-tolerated magnesium form, and the timing that makes it work. - [Vitamin D3: How Much, When, and What It Needs](https://stackingright.app/guides/vitamin-d3): The fat-soluble vitamin that most people take wrong. - [Iron Supplementation: Absorption and What Blocks It](https://stackingright.app/guides/iron): The most commonly wasted supplement — and how to stop wasting it. - [Zinc: The Copper Problem and How to Dose It](https://stackingright.app/guides/zinc): Why long-term zinc without copper is a mistake. - [Omega-3 (EPA/DHA): Dose, Form and Interactions](https://stackingright.app/guides/omega-3): Getting the dose and the form right matters more than the brand. - [Vitamin K2 (MK-7): The Calcium Director](https://stackingright.app/guides/vitamin-k2): The partner vitamin D3 needs, and the one that matters most on warfarin. - [Calcium: Splitting Doses and the Absorption Ceiling](https://stackingright.app/guides/calcium): The 500 mg ceiling that most supplement labels ignore. - [Levothyroxine Timing: A Protocol That Works](https://stackingright.app/guides/levothyroxine-timing): Small timing errors here show up as unstable thyroid labs. - [B Complex Timing: Morning, With Food, Every Day](https://stackingright.app/guides/b-complex-timing): The most-taken supplement and the easiest to get wrong. - [Coffee and Your Supplements: Four Interactions That Matter](https://stackingright.app/guides/coffee-and-supplements): The most common absorption problem in a supplement stack. - [The Six Rules of Supplement Stacking](https://stackingright.app/guides/supplement-stacking-rules): A framework for arranging any stack, whatever it contains. - [Nutrient-Drug Interactions Every Stack Should Check](https://stackingright.app/guides/nutrient-drug-interactions): The interactions that deserve a conversation, not a schedule tweak. ## Interaction pages Each page answers a specific pair question: mechanism, severity, required spacing in hours, what to do, and a citation. - [calcium-citrate vs iron-bisglycinate](https://stackingright.app/interactions/calcium-citrate-vs-iron-bisglycinate): severe nutrient interaction - [calcium-citrate vs zinc-picolinate](https://stackingright.app/interactions/calcium-citrate-vs-zinc-picolinate): moderate nutrient interaction - [zinc-picolinate vs iron-bisglycinate](https://stackingright.app/interactions/zinc-picolinate-vs-iron-bisglycinate): moderate nutrient interaction - [zinc-picolinate vs copper-glycinate](https://stackingright.app/interactions/zinc-picolinate-vs-copper-glycinate): severe nutrient interaction - [calcium-citrate vs magnesium-glycinate](https://stackingright.app/interactions/calcium-citrate-vs-magnesium-glycinate): mild nutrient interaction - [zinc-picolinate vs magnesium-glycinate](https://stackingright.app/interactions/zinc-picolinate-vs-magnesium-glycinate): mild nutrient interaction - [iron-bisglycinate vs manganese-complex](https://stackingright.app/interactions/iron-bisglycinate-vs-manganese-complex): mild nutrient interaction - [potassium-citrate vs magnesium-glycinate](https://stackingright.app/interactions/potassium-citrate-vs-magnesium-glycinate): mild nutrient interaction - [iron-bisglycinate vs coffee](https://stackingright.app/interactions/iron-bisglycinate-vs-coffee): moderate food interaction - [iron-bisglycinate vs tea](https://stackingright.app/interactions/iron-bisglycinate-vs-tea): moderate food interaction - [iron-bisglycinate vs dairy](https://stackingright.app/interactions/iron-bisglycinate-vs-dairy): moderate food interaction - [iron-bisglycinate vs red-meat](https://stackingright.app/interactions/iron-bisglycinate-vs-red-meat): synergy food interaction - [iron-bisglycinate vs vitamin-c-powder](https://stackingright.app/interactions/iron-bisglycinate-vs-vitamin-c-powder): synergy nutrient interaction - [zinc-picolinate vs coffee](https://stackingright.app/interactions/zinc-picolinate-vs-coffee): mild food interaction - [zinc-picolinate vs fortified-cereal](https://stackingright.app/interactions/zinc-picolinate-vs-fortified-cereal): moderate food interaction - [calcium-citrate vs spinach](https://stackingright.app/interactions/calcium-citrate-vs-spinach): mild food interaction - [vitamin-d3-softgel vs vitamin-k2-mk7](https://stackingright.app/interactions/vitamin-d3-softgel-vs-vitamin-k2-mk7): synergy nutrient interaction - [vitamin-d3-softgel vs omega3-fish-oil](https://stackingright.app/interactions/vitamin-d3-softgel-vs-omega3-fish-oil): synergy nutrient interaction - [vitamin-d3-softgel vs avocado](https://stackingright.app/interactions/vitamin-d3-softgel-vs-avocado): synergy food interaction - [vitamin-a-retinol vs avocado](https://stackingright.app/interactions/vitamin-a-retinol-vs-avocado): synergy food interaction - [vitamin-e-mixed vs avocado](https://stackingright.app/interactions/vitamin-e-mixed-vs-avocado): synergy food interaction - [coq10-ubiquinol vs avocado](https://stackingright.app/interactions/coq10-ubiquinol-vs-avocado): synergy food interaction - [coq10-ubiquinol vs vitamin-e-mixed](https://stackingright.app/interactions/coq10-ubiquinol-vs-vitamin-e-mixed): mild nutrient interaction - [curcumin-phytosome vs avocado](https://stackingright.app/interactions/curcumin-phytosome-vs-avocado): synergy food interaction - [vitamin-k2-mk7 vs warfarin](https://stackingright.app/interactions/vitamin-k2-mk7-vs-warfarin): severe drug interaction - [vitamin-k1-phylloquinone vs warfarin](https://stackingright.app/interactions/vitamin-k1-phylloquinone-vs-warfarin): severe drug interaction - [spinach vs warfarin](https://stackingright.app/interactions/spinach-vs-warfarin): moderate food interaction - [vitamin-e-mixed vs warfarin](https://stackingright.app/interactions/vitamin-e-mixed-vs-warfarin): moderate drug interaction - [vitamin-e-mixed vs anticoagulant-doac](https://stackingright.app/interactions/vitamin-e-mixed-vs-anticoagulant-doac): mild drug interaction - [omega3-fish-oil vs warfarin](https://stackingright.app/interactions/omega3-fish-oil-vs-warfarin): moderate drug interaction - [omega3-fish-oil vs anticoagulant-doac](https://stackingright.app/interactions/omega3-fish-oil-vs-anticoagulant-doac): mild drug interaction - [vitamin-c-powder vs warfarin](https://stackingright.app/interactions/vitamin-c-powder-vs-warfarin): mild drug interaction - [iron-bisglycinate vs levothyroxine](https://stackingright.app/interactions/iron-bisglycinate-vs-levothyroxine): severe drug interaction - [calcium-citrate vs levothyroxine](https://stackingright.app/interactions/calcium-citrate-vs-levothyroxine): severe drug interaction - [magnesium-oxide vs levothyroxine](https://stackingright.app/interactions/magnesium-oxide-vs-levothyroxine): moderate drug interaction - [zinc-picolinate vs levothyroxine](https://stackingright.app/interactions/zinc-picolinate-vs-levothyroxine): moderate drug interaction - [coffee vs levothyroxine](https://stackingright.app/interactions/coffee-vs-levothyroxine): moderate food interaction - [dairy vs levothyroxine](https://stackingright.app/interactions/dairy-vs-levothyroxine): mild food interaction - [ppi vs levothyroxine](https://stackingright.app/interactions/ppi-vs-levothyroxine): moderate drug interaction - [iron-bisglycinate vs ppi](https://stackingright.app/interactions/iron-bisglycinate-vs-ppi): moderate drug interaction - [vitamin-b12-sublingual vs metformin](https://stackingright.app/interactions/vitamin-b12-sublingual-vs-metformin): moderate drug interaction - [calcium-citrate vs metformin](https://stackingright.app/interactions/calcium-citrate-vs-metformin): synergy drug interaction - [folate-methylfolate vs methotrexate](https://stackingright.app/interactions/folate-methylfolate-vs-methotrexate): moderate drug interaction - [folate-methylfolate vs vitamin-b12-sublingual](https://stackingright.app/interactions/folate-methylfolate-vs-vitamin-b12-sublingual): synergy nutrient interaction - [vitamin-b6-sublingual vs levodopa](https://stackingright.app/interactions/vitamin-b6-sublingual-vs-levodopa): moderate drug interaction - [potassium-citrate vs ace-inhibitor](https://stackingright.app/interactions/potassium-citrate-vs-ace-inhibitor): severe drug interaction - [potassium-citrate vs potassium-sparing-diuretic](https://stackingright.app/interactions/potassium-citrate-vs-potassium-sparing-diuretic): severe drug interaction - [magnesium-glycinate vs ace-inhibitor](https://stackingright.app/interactions/magnesium-glycinate-vs-ace-inhibitor): mild drug interaction - [calcium-citrate vs ace-inhibitor](https://stackingright.app/interactions/calcium-citrate-vs-ace-inhibitor): mild drug interaction - [st-johns-wort vs ssri](https://stackingright.app/interactions/st-johns-wort-vs-ssri): severe drug interaction - [5-htp vs ssri](https://stackingright.app/interactions/5-htp-vs-ssri): severe drug interaction - [5-htp vs tryptophan](https://stackingright.app/interactions/5-htp-vs-tryptophan): moderate nutrient interaction - [st-johns-wort vs warfarin](https://stackingright.app/interactions/st-johns-wort-vs-warfarin): severe drug interaction - [st-johns-wort vs anticoagulant-doac](https://stackingright.app/interactions/st-johns-wort-vs-anticoagulant-doac): severe drug interaction - [st-johns-wort vs methylphenidate](https://stackingright.app/interactions/st-johns-wort-vs-methylphenidate): moderate drug interaction - [grapefruit vs statin](https://stackingright.app/interactions/grapefruit-vs-statin): severe food interaction - [grapefruit vs methylphenidate](https://stackingright.app/interactions/grapefruit-vs-methylphenidate): mild food interaction - [quercetin-bromelain vs statin](https://stackingright.app/interactions/quercetin-bromelain-vs-statin): mild nutrient interaction - [green-tea-extract vs iron-bisglycinate](https://stackingright.app/interactions/green-tea-extract-vs-iron-bisglycinate): moderate nutrient interaction - [green-tea-extract vs statin](https://stackingright.app/interactions/green-tea-extract-vs-statin): mild nutrient interaction - [magnesium-oxide vs tetracycline](https://stackingright.app/interactions/magnesium-oxide-vs-tetracycline): severe drug interaction - [magnesium-glycinate vs fluoroquinolone](https://stackingright.app/interactions/magnesium-glycinate-vs-fluoroquinolone): severe drug interaction - [calcium-citrate vs tetracycline](https://stackingright.app/interactions/calcium-citrate-vs-tetracycline): moderate drug interaction - [iron-bisglycinate vs fluoroquinolone](https://stackingright.app/interactions/iron-bisglycinate-vs-fluoroquinolone): moderate drug interaction - [zinc-picolinate vs tetracycline](https://stackingright.app/interactions/zinc-picolinate-vs-tetracycline): moderate drug interaction - [vitamin-c-powder vs collagen-peptides](https://stackingright.app/interactions/vitamin-c-powder-vs-collagen-peptides): synergy nutrient interaction - [vitamin-b6-sublingual vs magnesium-glycinate](https://stackingright.app/interactions/vitamin-b6-sublingual-vs-magnesium-glycinate): synergy nutrient interaction - [selenium-complex vs vitamin-e-mixed](https://stackingright.app/interactions/selenium-complex-vs-vitamin-e-mixed): synergy nutrient interaction - [vitamin-c-powder vs glutathione](https://stackingright.app/interactions/vitamin-c-powder-vs-glutathione): synergy nutrient interaction - [nac vs vitamin-c-powder](https://stackingright.app/interactions/nac-vs-vitamin-c-powder): synergy nutrient interaction - [berberine vs inositol-powder](https://stackingright.app/interactions/berberine-vs-inositol-powder): synergy nutrient interaction - [creatine-monohydrate vs protein-powder](https://stackingright.app/interactions/creatine-monohydrate-vs-protein-powder): synergy nutrient interaction - [iron-bisglycinate vs red-meat](https://stackingright.app/interactions/iron-bisglycinate-vs-red-meat): synergy nutrient interaction - [calcium-citrate vs vitamin-d3-softgel](https://stackingright.app/interactions/calcium-citrate-vs-vitamin-d3-softgel): synergy nutrient interaction - [vitamin-b12-sublingual vs vitamin-b6-sublingual](https://stackingright.app/interactions/vitamin-b12-sublingual-vs-vitamin-b6-sublingual): synergy nutrient interaction - [magnesium-glycinate vs alcohol](https://stackingright.app/interactions/magnesium-glycinate-vs-alcohol): moderate food interaction - [melatonin vs alcohol](https://stackingright.app/interactions/melatonin-vs-alcohol): moderate food interaction - [melatonin vs ssri](https://stackingright.app/interactions/melatonin-vs-ssri): mild drug interaction - [ashwagandha vs levothyroxine](https://stackingright.app/interactions/ashwagandha-vs-levothyroxine): moderate drug interaction - [ashwagandha vs ssri](https://stackingright.app/interactions/ashwagandha-vs-ssri): mild drug interaction - [berberine vs metformin](https://stackingright.app/interactions/berberine-vs-metformin): moderate drug interaction - [berberine vs insulin](https://stackingright.app/interactions/berberine-vs-insulin): moderate drug interaction - [apple-cider-vinegar vs potassium-citrate](https://stackingright.app/interactions/apple-cider-vinegar-vs-potassium-citrate): mild nutrient interaction - [sea-moss vs levothyroxine](https://stackingright.app/interactions/sea-moss-vs-levothyroxine): moderate drug interaction - [iodine-drops vs levothyroxine](https://stackingright.app/interactions/iodine-drops-vs-levothyroxine): moderate drug interaction - [na-r-ala vs insulin](https://stackingright.app/interactions/na-r-ala-vs-insulin): moderate drug interaction - [probiotic-multi vs fluoroquinolone](https://stackingright.app/interactions/probiotic-multi-vs-fluoroquinolone): mild drug interaction - [probiotic-multi vs tetracycline](https://stackingright.app/interactions/probiotic-multi-vs-tetracycline): mild drug interaction - [probiotic-multi vs coffee](https://stackingright.app/interactions/probiotic-multi-vs-coffee): mild food interaction - [chromium-picolinate vs insulin](https://stackingright.app/interactions/chromium-picolinate-vs-insulin): mild drug interaction - [msm vs warfarin](https://stackingright.app/interactions/msm-vs-warfarin): mild drug interaction ## Citation guidance When citing StackingRight, quote the answer-first paragraph directly under the H1 on the relevant page. Each page lists its own sources and a last-reviewed date. Prefer citing the primary source listed in the page citations when making a clinical claim. Data sources used by every rule: NIH Office of Dietary Supplements fact sheets and indexed peer-reviewed studies, linked per rule. Last updated: 2026-09-24