What to check before buying any supplement
Last updated: June 2026 · Reviewed by the FactoWiki Editorial Team for clarity and source accuracy
Before buying any supplement, check seven things: the ingredients, dosage transparency, safety warnings, refund policy, seller reputation, credible source links, and whether the claims are realistic rather than miraculous.
Key takeaways
- Disclosed doses beat hidden “proprietary blends.”
- Realistic “support” language beats cure or “guaranteed” claims.
- A credible seller and real refund policy reduce your risk.
Ingredients and disclosed doses
Start with the supplement facts panel, not the sales page. You want to see each active ingredient listed with its specific dose, at amounts comparable to what studies actually used — not buried in a single “proprietary blend” figure that hides how much of anything you’re getting. A long list of trendy ingredients at trace doses is padding designed to impress. Transparency about what’s inside, and how much, is the foundation of a trustworthy product.Claims, safety and sources
Read the claims critically. Honest products describe “support” for normal function; ones to avoid promise to cure, reverse, or guarantee results, or to replace medication — none of which a supplement can legitimately claim. Look for honest safety information (who should avoid it, interactions) and credible source links to real research or health bodies, rather than vague “studies show” hand-waving. A brand that states limits and cautions is signalling more credibility than one offering only miracles.Seller, guarantee and pressure tactics
Finally, judge who you’re buying from. Look for a real company with contact details, transparent sourcing, third-party testing where possible, and a clear, genuinely usable refund policy. Treat fake urgency — countdown timers, “only a few left,” invented testimonials — as a warning, not a reason to hurry. If you can’t easily find who’s behind a product or how to get your money back, that uncertainty alone is a good reason to choose a more transparent option.Key ingredients to understand
If you’re weighing up a blood sugar & metabolism product, these are two of the ingredients worth knowing about — what they may do, and where the evidence stands:
- Berberine — Berberine is a plant compound studied mainly for blood sugar, cholesterol and related metabolic markers. It has some of the strongest human research of any natural supplement ingre…
- Magnesium — Magnesium is an essential mineral involved in hundreds of body processes, including nerve and muscle function, energy and blood-sugar control. Many people fall short of the recomme…
What to check before you buy
Across every category, the same rules apply: look for fully disclosed doses (not hidden proprietary blends), realistic language, clear seller details and refund terms, and credible source links. Treat any “cure”, “guaranteed” or “instant” claim as a red flag, and loop in a healthcare professional if you take medication or manage a condition.
Frequently asked questions
What’s the single most important thing to check?
Disclosed, meaningful doses — a “proprietary blend” that hides amounts makes a product impossible to judge.
What claims should make me walk away?
Anything about curing or reversing disease, guaranteeing results, or replacing medication — these are red flags.
Does a money-back guarantee prove it works?
No — it’s consumer protection, not proof of efficacy, though a clear refund policy signals a more trustworthy seller.
Related on FactoWiki
- Blood Sugar & Metabolism supplements — the full category
- Berberine — ingredient guide
- Magnesium — ingredient guide
- Java Burn review
- Gluco Extend review
- Nervora review
This article is general information, not medical advice. FactoWiki may earn a commission from links on product review pages (never on comparisons). Always check with a qualified healthcare professional about your own situation.