Publisher and editor
David L.
I select the topics, check the sources, edit every draft, and approve what Better Health Shelf publishes.
How I work
I start with the product label or care option a reader is trying to understand. I check claims against first-party and authoritative sources such as FDA, NIH, and NCCIH, then keep the useful facts, limits, and uncertainties visible.
AI can help with drafting, but I am responsible for the published copy. Commercial relationships do not determine the conclusions.
What I do not claim
I am not a clinician, and this page does not claim medical credentials. These guides provide general education, not diagnosis, individual dosing, treatment eligibility, or medical advice.
Read the full editorial methodology, corrections policy, and affiliate disclosure.
Guides by David L.
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.
Supplement basics · Updated 9/13/2026Can 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.
Label literacy · Updated 8/27/2026Added sugars vs. total sugars
Learn whether added sugar is included in total sugar, how to read grams and percent Daily Value, and what common label examples mean.
Label literacy · Updated 8/27/2026How to read food allergen labels
Find the nine major allergens in ingredient and Contains statements, understand “may contain,” and check packaged foods and supplements.
Supplement basics · Updated 8/27/2026Ashwagandha supplement labels: root, extract, withanolides, and safety
Read ashwagandha supplement labels by plant part, powder or extract, withanolides, serving size, certification, and safety limits.
Everyday health · Updated 8/27/2026How to read a caffeine label
Track caffeine by milligrams per serving and container across coffee, tea, soda, energy drinks, powders, pre-workouts, supplements, and medicines.
Supplement basics · Updated 8/27/2026Calcium 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.
Everyday health · Updated 8/27/2026How to calculate cost per serving
Calculate price per serving, piece, gram, or declared ingredient amount while including shipping, subscriptions, and changing serving sizes.
Supplement basics · Updated 8/27/2026Creatine 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.
Everyday health · Updated 8/27/2026Electrolyte powder labels: sodium, potassium, and sugar
Read electrolyte powder labels by sodium, potassium, magnesium, serving size, water volume, added sugars, sweeteners, caffeine, and safety limits.
Supplement basics · Updated 8/27/2026Fiber 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.
Label literacy · Updated 8/27/2026What does gluten-free mean on a food label?
Learn FDA’s gluten-free definition, the less-than-20-ppm limit, how wheat-free differs, and what to check on packaged foods.
Supplement basics · Updated 8/27/2026Gummies vs. capsules vs. powders: what changes?
Compare supplement formats by serving size, ingredient amount, added ingredients, measuring, storage, portability, and package cost.
Metabolic health · Updated 8/27/2026How to verify an online pharmacy
Verify an online pharmacy through state licensing records, prescription requirements, pharmacist access, contact details, privacy terms, and independent checks.
Supplement basics · Updated 8/27/2026How 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.
Label literacy · Updated 8/27/2026How to read a Supplement Facts label, step by step
Read a dietary-supplement label in order: serving size, ingredient amounts, Daily Value, other ingredients, claims, certification, and company details.
Label literacy · Updated 8/27/2026What is a structure/function claim on a supplement?
Learn what structure/function claims mean, how they differ from health and disease claims, and what the FDA disclaimer does not prove.
Supplement basics · Updated 8/27/2026How 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.
Supplement basics · Updated 8/27/2026Iron 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.
Supplement basics · Updated 8/27/2026Magnesium 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.
Everyday health · Updated 8/27/2026Melatonin supplement labels: mg, serving size, release, and safety
Read melatonin labels by milligrams, pieces per serving, immediate- or extended-release wording, added ingredients, testing, and safety limits.
Supplement basics · Updated 8/27/2026Fish 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.
Label literacy · Updated 8/27/2026What does percent Daily Value mean?
Learn how percent Daily Value works per serving, what 5% and 20% mean, how to calculate it, and why it is not a personal target.
Everyday health · Updated 8/27/2026How to read a pre-workout or performance supplement label
Check serving size, ingredient amounts, stimulant totals, proprietary blends, evidence, certification, and sport rules before buying.
Supplement basics · Updated 8/27/2026Probiotic 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.
Label literacy · Updated 8/27/2026What is a proprietary blend?
Learn how proprietary blends list total weight and ingredient order while leaving individual amounts undisclosed—and what that means for label research.
Label literacy · Updated 8/27/2026Serving size vs. servings per container
Learn what serving size and servings per container mean, then calculate amounts per capsule, scoop, packet, bottle, or other unit.
Label literacy · Updated 8/27/2026How to read sodium on a Nutrition Facts label
Read sodium by milligrams, percent Daily Value, serving size, package math, and the exact meaning of low- or reduced-sodium claims.
Label literacy · Updated 8/27/2026Supplement Facts vs. Other Ingredients
Learn which ingredients belong in each section, how to read amounts and sources, and why “other” does not mean unimportant or inactive.
Label literacy · Updated 8/27/2026What does third-party tested mean?
Learn the difference between testing and certification, what USP and NSF marks cover, how to verify a listing, and what no seal can prove.
Supplement basics · Updated 8/27/2026Vitamin 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.
Supplement basics · Updated 8/27/2026Vitamin 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.
Metabolic health · Updated 8/27/2026How to evaluate weight-loss supplement claims
Check fat-burner, appetite, metabolism, and rapid-loss claims against the exact ingredients, amounts, evidence, stimulant total, and safety record.
Supplement basics · Updated 8/27/2026Whey 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.
Metabolic health · Updated 8/26/2026GLP-1 medications: how they work, benefits, and side effects
Understand what GLP-1 receptor agonists do, where their potential benefits come from, common side effects, serious warnings, and why the exact medication matters.