Customers at The Organic Pharmacy’s flagship store in London can now get their DNA tested in order to determine the best beauty products suited to their skin type.

British firm geneOnyx is launching the reportedly first in-store DNA tests that give London shoppers a helping hand — choosing skincare products genetically suited to their skin type, as well as providing details about how quickly their skin will age.

The service requires little more than a bit of spit from the customer and some 30 minutes’ wait time while their DNA is analyzed in the store, without the hassle of sending it off to a lab.

Once results are obtained, they are cross-referenced with geneOnyx’s database of skincare product ingredients. Then customers can be advised which products they’ll need to purchase to achieve top results — all for a price tag of £295 ($495), that is, not including the products.

“Our DNA determines when we start showing the signs of aging and how quickly our skin ages,” says Margo Marrone, founder of The Organic Pharmacy.

“The technological advances unique to the geneOnyx system now mean that we can assess how likely you are to age early and also your ability to metabolize active anti-aging ingredients used in our products.”