# How we grade evidence

Source: https://shilajit.uk/about/evidence-grades/
Author: Sam Rowan · Updated 2026-10-16

**Short answer:** Shilajit.uk grades every health claim as strong, moderate, weak or no evidence, based on how many human trials have tested it, how well they were run and whether their results agree. Animal and lab studies alone can never earn more than a weak grade.

## The four grades

| Grade | What it means |
| --- | --- |
| **Strong** | Several well-run randomised controlled trials in humans agree, ideally confirmed by a systematic review. |
| **Moderate** | At least one well-run randomised controlled trial in humans supports the claim, but it hasn't been independently repeated. |
| **Weak** | The only human evidence is small, short or poorly controlled, or the claim rests on animal and laboratory studies alone. |
| **None** | No human studies support the claim, or the studies that exist found no effect. |

## What we look at

- **Who was studied:** humans count far more than animals or cells in a dish.
- **Size and length:** a 12-week trial with 100 people tells us more than a 4-week trial with 20.
- **Design:** randomised, placebo-controlled and double-blind trials are the most reliable.
- **Funding:** we note when a study was paid for by a company that sells the product tested.
- **Product:** results from one standardised extract don't automatically apply to every shilajit product.

## When grades change

Grades are reviewed whenever a page is updated. If new research changes a grade, we say so on the page.