Cytochrome P450 2C19
CYP2C19 handles several SSRIs (citalopram, escitalopram, sertraline), proton pump inhibitors (omeprazole, esomeprazole), and the blood thinner clopidogrel.[1] About 2 to 5 percent of people of European descent and 15 to 20 percent of people of East Asian descent are poor metabolizers. Another 30 percent carry a rapid-metabolizer variant.[2]
Gene2Rx reports your CYP2C19 genotype across 36 named star alleles, built from 32 variants curated by PharmVar.
Star alleles (like *1, *2, *4) are standardized names for distinct versions of a pharmacogene. *1 is the reference; higher numbers identify variants discovered later that change the enzyme's activity.
You inherit one allele from each parent, so your genotype is a pair (e.g. *1/*4). The pair determines your predicted phenotype — for example, whether you metabolize a drug at a normal, decreased, or no-function rate.
PharmVar is the international registry that defines and curates these allele names. Gene2Rx tests the variants required to call every CYP2C19 allele in the PharmVar catalog.
Gene2Rx covers 21 medications with published pharmacogenetic guidance for CYP2C19, drawn from CPIC and FDA sources. Each drug links to its full pharmacogenetics page.
These branded medications include at least one active ingredient whose metabolism or action involves CYP2C19. Each links to its full pharmacogenetic breakdown.
This page lists drugs affected by CYP2C19. A Gene2Rx report tells you which metabolizer group you fall into, and what that means for every medication on this list.
Get your report Look up a medicationInformational only, not medical advice. The presence of a CYP2C19 pharmacogenetic guideline does not mean every patient needs to change their dose. Never start, stop, or change a medication without talking to your prescribing clinician.