Find out about our business model, our lab testing process and how we calibrate the Gscreen score.

  • About Gscreen
  • The Gscreen Rating
  • Gscreen Testing

We do not accept contributions or donations of any kind from manufacturers to rank products on our site.

How do Gscreen make money?

Greenscreen makes money in two ways. First, we receive a portion of every pound spent by consumers who purchase products directly from our site. Second, we offer testing services for companies that need independent validation of their product quality.

Why does Gscreen sell products? How does it stay unbiased?

We believe that if a product catches your eye, it should be a product you can buy! This is why we sell the products that have been Greenscreened. We avoid bias by selling products regardless of the Gscreen rating they have been given, so you can make an informed decision on what suits your needs best.

Does Gscreen provide professional medical advice?

No - in the UK we are restricted from advertising the medicinal benefits of CBD.



Gscreen Rating is based on independent lab tests, conducted and verified by Gscreen’s partners and in house experts.

Gscreen Rating takes into account a number of factors, including:



The cannabinoid extraction process is volatile and can leave trace elements of harmful compounds.

To make sure all products we list are safe, Gscreen measures:

  • Adherence to the legal limit of THC
  • Heavy metals content
  • Presence of harmful microbes
  • Presence of Gscreen’s watchlist ingredients
  • Adherence industry best manufacturing practices



Because of the popularity of CBD, it’s easy to get tricked into paying premium prices for sub-par products.

To make sure this doesn’t happen, the Greenscreen Rating measures products against others in similar categories with similar amounts of CBD.


Label Accuracy

The Centre for Medicinal Cannabis found in 2019 that 62% of the UK high street products didn’t contain the CBD content promised on the label.

Gscreen measures a product’s measured levels of active ingredients vs. its label claims.

Products are penalised if their active ingredient levels are lower than what they claim.



The bioavailability of products and their mix of cannabinoids alter the way CBD can be absorbed and used.

Each product is assessed on the cannabinoid profile and how well the body can absorb and use it.


Carbon Footprint

Many products are made from materials that come from a different country to where the product is sold.

In order to encourage a reduction in carbon footprint, each product is assessed on whether it was wholly, partly or not at all made in the country where it is being sold.


1. We select products for testing.

2. We select products based on market research of popular products.

3. We collect testing data.

4. Analytical chemistry assays are performed on samples of each product. Default analyses include measurements of active ingredients and potential contaminants.

5. We convert the data into the Gscreen Rating.

6. We calculate the Gscreen Rating using laboratory results and label claims from each product. The Gscreen Rating is comprised of individual scores for Label Accuracy, Efficacy, Safety, Value and Carbon Footprint.

7. We give consumers a clear perspective.

8. We offer consumers a range of the best products on the market and take confusion out of the decision.  

9. We help brands improve their products. There's always room for improvement! We combine our data showing what consumers want with our laboratory analysis in order to provide insights to brands on how to improve their products.