Compendium supplements, read carefully
Safety 29 July 2026 2 min read 3 sources

How to read a supplement label: seven checks

Supplements are not tested for effectiveness the way medicines are. That leaves the label — and it is worth reading properly.

Bottles on a pharmacy shelf
Bottles on a pharmacy shelf

A dietary supplement is not registered as a medicine: the manufacturer does not have to prove a therapeutic effect. The label is therefore your main tool.

Seven things to check

  1. The active compound and its form. "Magnesium 500 mg" and "magnesium citrate 500 mg" are different amounts of elemental magnesium.
  2. The dose per serving and the serving size. Sometimes the advertised dose takes three capsules.
  3. The percentage of the daily value. Numbers in the hundreds are a reason to look closer, not a selling point.
  4. The full ingredient list, including fillers, colours and allergens.
  5. Who made it, and whether batches are independently tested (USP, NSF, Informed Choice).
  6. Expiry date and storage conditions.
  7. The wording on the pack. "Treats", "restores your liver" or "flushes out toxins" means marketing has outrun the evidence.

Red flags

  • A proprietary blend with no doses for its components.
  • Testimonials where the ingredient list should be.
  • Sold only through a closed chat group or a personal consultant.
  • "WHO approved" — the WHO does not approve supplements.

A calm approach

A supplement earns its place when there is a deficiency or a specific goal supported by data. The rest is expensive urine, and that is a literal description of what happens to surplus water-soluble vitamins.

Sources

  1. U.S. Food and Drug Administration. Dietary Supplements: What You Need to Know.
  2. NIH Office of Dietary Supplements. Dietary Supplement Label Database.
  3. European Food Safety Authority. Food supplements — general guidance.
This is information, not advice. It does not prescribe treatment and does not replace a conversation with a doctor or pharmacist. Doses, indications and whether something fits alongside your other medicines are decisions for a clinician who knows your history.

Back to all articles