Understanding Evidence Ratings
Every rating on this page describes the state of the research, not a judgment about whether something is right for you. Ratings apply to one outcome and one group of people at a time, so the same ingredient can be rated differently in different rows.
- Proven
- Multiple human studies consistently show it works for this.
- Promising
- Human studies show it works, but there are only a few of them.
- Early
- Results look good in lab or animal research, but it hasn't been properly tested in people yet.
- Untested
- No meaningful research exists for this specific use.
- Doesn't work
- It has been studied for this, and the research shows it doesn't help.
Separately, each row notes what's known about safety: whether long-term use has been studied, whether there are cautions to be aware of, or whether safety data is still missing. Strong evidence that something works is not the same as evidence that it's safe to take indefinitely.
If your practitioner has recommended something rated Early or Untested, that isn't a contradiction. Clinicians often work ahead of published research, and they know things about your situation that a general rating can't account for. Bring the question to them.
Every other supplement type is rated on a 1-10 effectiveness score. Read about effectiveness scores.