16 guides
Supplement basics
Plain-language guides to common ingredients and formats.
Read the label first, then follow the details that matter to your question.
Start with the label
Choose a question, not a promise.
Serving size, ingredients, claims, testing, and practical limits all deserve their own check.
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All 16 guides
Supplements before surgery: what to tell your care team
Prepare a supplement list for surgery or anesthesia: what labels to bring, why they matter, and which stop-and-restart questions to ask your care team.
Can biotin supplements affect blood test results?
Biotin can distort some blood test results. Learn which labels to check, why the test method matters, and what to tell your clinician or lab.
Ashwagandha supplement labels: root, extract, withanolides, and safety
Read ashwagandha supplement labels by plant part, powder or extract, withanolides, serving size, certification, and safety limits.
Calcium supplement labels: carbonate, citrate, and amount
Read calcium supplement labels by milligrams, percent Daily Value, carbonate or citrate form, tablets per serving, vitamin D, other ingredients, and medicine interactions.
Creatine monohydrate labels: what to check before choosing
Read creatine labels by form, amount per serving, serving math, added ingredients, certification, and claims the label cannot prove.
Fiber supplement labels: grams, fiber source, format, and fluids
Read fiber supplement labels by grams per serving, percent Daily Value, fiber source, powder or capsule format, added ingredients, and fluid directions.
Gummies vs. capsules vs. powders: what changes?
Compare supplement formats by serving size, ingredient amount, added ingredients, measuring, storage, portability, and package cost.
How to read a multivitamin label
Read multivitamin labels by pills per serving, nutrient amounts and units, percent Daily Value, missing nutrients, added ingredients, overlaps, and safety limits.
How to report a dietary supplement problem to FDA
Get appropriate help, preserve the package and lot details, document what happened, and submit a dietary supplement report to FDA.
Iron supplement labels: amount, form, and safety
Read iron supplement labels by milligrams, percent Daily Value, iron form, pills or gummies per serving, other sources, medicine interactions, and child-safety warnings.
Magnesium supplement labels: elemental magnesium, forms, and serving size
Read magnesium and magnesium-glycinate labels by elemental magnesium, form, serving size, Daily Value, other sources, and safety details.
Fish oil and omega-3 labels: EPA, DHA, total oil, and serving size
Read fish-oil and omega-3 labels by EPA, DHA, ALA, total oil, serving size, source, allergens, other ingredients, and testing details.
Probiotic labels: strain, CFU, expiration, and storage
Read probiotic labels by genus, species, strain, CFU per serving, expiration-date guarantee, refrigeration, other ingredients, certification, and safety limits.
Vitamin B12 supplement labels: mcg, forms, serving size, and absorption
Read B12 labels by micrograms, percent Daily Value, serving size, cyanocobalamin or methylcobalamin, absorption, format, and other sources.
Vitamin D supplement labels: mcg, IU, D2, D3, and serving size
Read vitamin D labels by converting mcg and IU, checking serving size, D2 or D3, Daily Value, other sources, ingredients, and safety details.
Whey protein labels: isolate, concentrate, serving math, and allergens
Read whey protein labels by protein per serving, isolate or concentrate, package math, added ingredients, milk allergens, and certification.