Our method

How the Vitarrow Rating works

Every product in the guide carries a rating from 0 to 10. Here is exactly what that number is, and what it is not.

What goes into it

The rating is built from three pieces of publicly available marketplace performance data, published by the retail platform that sells these products:

How many sellers are successfully recommending it. This is the heaviest input. A product that many independent affiliates are able to sell is a product that holds up with real customers.
Average earnings per visit. A practical signal of whether people who look at the product go on to buy it.
Conversion rate. The share of visitors who complete a purchase.

Ratings are relative within a category

A sleep formula is scored against other sleep formulas, not against weight-loss products. Categories differ enormously in size and competition, so a single global scale would tell you almost nothing. Scoring within the category answers the question you are actually asking: of the options for my concern, which are performing best?

This means the top product in a small category and the top product in a large one can both score highly. That is intentional.

What the rating is not

It is not a clinical or scientific evaluation. We do not run trials, commission lab testing, or assess ingredient safety or efficacy.

It is not a health recommendation. A high rating means a product is selling well and being widely recommended within its category — nothing more.

It is not influenced by payment. No seller can buy a higher rating or better placement.

How often it updates

Marketplace data shifts constantly. We refresh our figures periodically and recalculate every rating at the same time, so the guide reflects what is performing now rather than what performed a year ago.

Where the money comes from

We earn a commission when you buy through our links, at no extra cost to you. Because every product in the guide pays a commission, commission plays no part in ranking. See About for more.