A gene for caffeine metabolism

Caffeine has been used by athletes for a long time as a performance-enhancing drug. Studies have shown that taking caffeine improves performance in sports and exercise. Your FitnessGenes result tells you which caffeine-clearing molecule you carry and how long you can expect it to take for caffeine to be removed from the bloodstream.

Caffeine is a stimulant and the most commonly used drug on the planet. What used to be a chemical only associated with coffee is now in chocolate, ice cream, weight-loss pills, energy and alcoholic drinks, mints, study aids, marshmallows, and non-prescription painkillers. There is even caffeine in decaffeinated coffee! Despite its universal acceptance and widespread availability, caffeine is a toxic compound and overdose is lethal — consumption of as little as a few grams can result in death; nevertheless, enough caffeine to kill an adult is still, legally, only a click away.

Although it is socially acceptable in high street coffee shops, caffeine used to be banned as a performance-enhancing drug in athletes. Prior to 2004, the World Anti-Doping Agency restricted the use of caffeine and athletes could be disqualified if levels in their urine were above a set threshold. Caffeine is also still on the list of National Collegiate Athletic Association banned substances. Even the US Food and Drug Administration (FDA) stepped into caffeine regulation in 2013 by encouraging Wrigley to cease production and sales of its caffeine-infused chewing gum and have issued a public warning recommending consumers avoid powdered pure caffeine due to the dangers of an accidental overdose.

We have analysed data on caffeine metabolism from multiple studies (totaling 635 individuals of varying age, sex, and ethnicity) in order to advise you on how long you can expect a 100mg and 200mg dose of caffeine to stay in your system based on your gene result. We test the gene that codes for the CYP1A2 protein, which is responsible for metabolising any caffeine you ingest. Your genetic variation in combination with specific environmental factors can affect the rate at which you metabolise caffeine.

You can find more information about the CYP1A2 gene in our member area at where you can also find your results and what this means for you after your DNA has been analyzed by us. Head over to the shop to order your Fitnessgenes DNA analysis and genetic training system


We have fully reviewed the impact of this gene and the genetic variant we analyse as part of our scientific research process. You can access the full citation list on all studies reviewed here.

Sign up to our newsletter

Keep up to date with the latest gene releases, scientific research and training news from FitnessGenes by subscribing to our weekly newsletter. Exclusive science and training articles from the FitnessGenes team and guest writers will help you understand the full potential of unlocking your Fitness DNA.

FitnessGenes Genetic Guide to Food ebook

Free Genetic Guide to Food ebook

Learn how you can achieve your fitness and body composition goals with our Special Report: Genetics and Your Diet.

Use Facebook to sign up to our newsletter and receive your free ebook