Short answer: A useful supplement quality check starts with the label, not a marketing slogan. Read the Supplement Facts panel and serving size, compare ingredient amounts, look at other ingredients and warnings, and check whether any independent certification can be verified for the exact product. Then consider the evidence for its claims, your own medicines and health needs, and the seller’s contact and return information. Dietary supplements are generally not approved by the FDA for safety or effectiveness before sale.
By · Last updated: October 15, 2026
Use these eight checks when comparing any brand. They help you ask better questions; they cannot guarantee that a supplement is effective or right for you. If you take medicines, are pregnant, or have a health condition, discuss supplements with a qualified health professional before use.
| Check | What to ask |
|---|---|
| Supplement Facts | Does the panel show serving size and servings per container? |
| Ingredient amounts | Can you see the amount of each dietary ingredient per serving? |
| Other ingredients | Have you read the full ingredient list and warnings? |
| Manufacturing | Does the seller explain its quality controls without treating FDA registration as product approval? |
| Independent verification | Can you verify a claimed seal for this exact product? |
| Evidence | Is the claimed benefit supported by relevant research? |
| Personal safety | Could an ingredient interact with your medicines or health conditions? |
| Seller information | Can you identify the responsible business and read its return terms? |
1. Read the Supplement Facts panel
Start with Serving Size and Servings Per Container. A bottle containing 60 capsules is not necessarily 60 servings: if the serving size is two capsules, it contains 30 servings. The FDA’s dietary supplement labeling guide explains the information that belongs in the panel. Compare products on a per-serving basis before comparing prices.
If you are new to the panel, our guide to reading a Supplement Facts label explains the serving size, ingredient and capsule-count fields.
2. Compare ingredient amounts, not just names
Two bottles can name the same nutrient while providing very different amounts per serving. Read the unit beside the amount, such as milligrams or micrograms, and do not confuse a bottle’s total capsule count with a daily dose. Some dietary ingredients have no established Daily Value; the FDA still requires their amounts to be listed in the Supplement Facts panel. A proprietary blend may give a total blend weight without listing each component’s individual amount, which makes direct comparison harder.
For questions about a particular vitamin, mineral or herb, use the NIH Office of Dietary Supplements fact sheets rather than assuming a larger number is always better.
3. Read the other ingredients and warnings
The ingredients outside the active dietary ingredients matter too. Read the complete ingredient list for capsules, flavors, colors and other substances you may wish to avoid. Check the physical label for directions and warnings, especially if you have a known sensitivity. A website summary may leave out details that appear on the package. If the full label is not available online, ask the seller for it before ordering.
4. Understand manufacturing claims
Manufacturers, packers and holders of dietary supplements are subject to FDA current good manufacturing practice requirements. These rules address identity, purity, quality, strength and composition, but the phrase “FDA-registered facility” does not mean that the FDA approved an individual supplement. The FDA generally does not approve supplements or their claims before marketing. Its dietary supplement Q&A explains the distinction. Ask a brand for the specific quality documentation behind a claim instead of treating a registration statement as a seal of approval.
5. Verify any independent seal
Use the third-party testing guide and official certification directories to match the exact product and check the scope of the claim.
A named third-party program can offer useful evidence about quality when the exact product is certified. For example, the USP Verified program checks declared ingredients and amounts, specified contaminants, manufacturing practices and product performance. Look up the particular product in the issuing organization’s directory; a vague “lab tested” statement is not the same as a verifiable certification. A quality seal does not show that a supplement will produce a claimed health benefit for everyone.
6. Ask what supports the benefit claim
Separate research on an ingredient from evidence on the finished product and its actual dose. A promising study of a different formula does not prove that the bottle in your cart works the same way. The FTC’s health-products guidance explains that health-related advertising claims should be truthful, not misleading and supported by appropriate evidence. Be skeptical of promises to cure a disease or deliver guaranteed rapid results.
7. Check whether it is suitable for you
Supplements can interact with medicines and may be unsuitable for some people. Consider everything you already take, including other supplements. The NIH consumer guide recommends discussing supplement use with your health care providers. Do not replace a prescribed treatment with a supplement based on an online claim. The right choice can depend on your medicines, health conditions, age and other individual factors.
8. Check the seller and the practical terms
The package should identify the manufacturer, packer or distributor; the FDA’s general labeling guide describes required label statements. Check that a seller’s product page, bottle count and label photographs match what you intend to buy. Read the posted return policy before ordering. A return policy is useful customer information, but it is not evidence that a supplement is safe or effective.
Before you choose
Save a clear image of the Supplement Facts and ingredient lists, confirm the serving size, and write down the specific claim you want to evaluate. If you take medication or have a health concern, bring that information to a doctor or pharmacist. You can browse available Valdivia Life listings and apply the same questions to any product you compare. This article is general consumer information, not personal medical advice or a guarantee about any product.
This article is for general information only and is not medical advice. Supplements are not a substitute for diagnosis or treatment by a qualified healthcare provider. Statements about dietary supplements have not been evaluated by the Food and Drug Administration, and supplements are not intended to diagnose, treat, cure, or prevent any disease.