Start with the complete label
Review the ingredients, quantities per serving, suggested use and warnings. Similar product names do not establish equivalent formulas. Compare the actual label rather than a dramatic headline or an ingredient mentioned in isolation.
Discuss personal suitability
Bring the current label and a list of medicines and other supplements to a qualified healthcare professional. This is especially useful when you have a health condition, use medication, are pregnant or are considering a product for a child.
Keep marketing separate from treatment
A supplement listing does not establish that the product treats a disease or is appropriate for you. FDA does not approve dietary supplements for safety and effectiveness before they are marketed. Read the agency’s consumer information and discuss decisions with a qualified professional.
Compare the actual purchase
Look at serving count, total quantity, shipping, taxes and any recurring order option. Check the seller’s current refund rules; a guarantee is a purchase condition, not evidence of a health benefit.
Further reading: FDA: information for consumers using dietary supplements ↗.