Supplement guides
Supplement guides, page 8
Plain-English guides on labels, doses, real prices, free trials and refunds. Written to help you check a product, not to sell you one.
Is the 6-bottle supplement bundle worth it? The price-per-bottle math
The bottle math behind 1, 3 and 6 bottle supplement bundles, and why the refund window matters more than the discount.
EvidenceSleep aid supplements: what NIH says on valerian and magnesium
What NIH's NCCIH says about valerian, melatonin, magnesium and other sleep supplements, and how to read a sleep formula before you buy.
EvidenceSmall and industry-funded supplement trials: how much to trust
Sample size, funding bias and replication: how to weigh the one trial a supplement page is built on.
RegulationStructure/function claims vs disease claims on supplement labels
How to tell what a supplement may legally claim, what the FDA disclaimer means, and how disease claims are defined.
SafetySupplement and drug interactions: what to check before you buy
How supplements can interact with medicines, the St. John's wort example, what sales pages leave out, and questions to ask a pharmacist before you order.
LabelsSupplement expiration dates and storage: what the label date really means
FDA rules make expiration dates optional on supplements. See what dates mean, how to store bottles, and what to check before a six-bottle bundle.
ResearchSupplement review sites and affiliate bias: how to judge one
How affiliate commissions can bias supplement reviews, what the FTC says about disclosure, and a checklist for judging any site, including our own.
SafetyAre supplements safe for older adults on several medications?
What the NIA, NCCIH and FDA say about mixing supplements and medicines after 50, and which ingredients to raise with a pharmacist.
SafetyIs it safe to stack supplements that share the same ingredient?
How overlapping ingredients add up across products, the adult upper limits for zinc, vitamin A, niacin and more, and a six-step way to check your own stack.
PricingSupplement upsell pages: what to decline and how to spot them
One-click bottles, pre-checked add-ons and exit offers: what our reviews recorded, four questions to ask, and how to fix an accidental add-on.
Guides are general information, not medical advice. Read how we review and our medical disclaimer.