How we rate products

Every rating answers one question: how well does published research support what this product claims to do?

The four levels

  • Strong evidence

    Several good-quality trials in people, with consistent results. Often a licensed medicine.

  • Some evidence

    At least one decent trial in people, or strong indirect evidence, but results are limited or not yet repeated.

  • Weak evidence

    Small trials, trials in a different group (for example men only), or data published only by the ingredient supplier or brand.

  • No evidence

    No published research in people that we could find. The product may still feel nice to use.

What we check

  • Whether studies were in people, and in women of menopause age.
  • How many people took part and for how long.
  • Who paid for and published the study.
  • Whether the brand's claims match what the study actually found.

What a rating does not mean

A low rating does not mean a product is unsafe or useless for you. It means the research does not yet show it works. A high rating does not mean it suits everyone; always read the label and check with a pharmacist if you take other medicines.

Money and independence

We earn commission when you buy through some of our links. Brands cannot pay for a rating, and we rate products we do not earn from in the same way. Read our affiliate disclosure.

Corrections

If you spot a mistake or a newer study, email [email protected]. We review ratings at least every six months and show the date on each page.