Millions of Americans currently take acid reflux or ulcer medications.
Over half of all medications including many acid reflux and ulcer medications, such as Prilosec® (omeprazole) and Nexium® (esomeprazole), are metabolized by two enzymes found primarily in the liver called CYP3A4 and CYP2C19.[1,18]
Population Frequency of Cytochrome P450 (CYP) Metabolizer Types 
(no or low enzyme levels)
|Intermediate(reduced enzyme levels)||Normal (normal enzyme levels)||Rapid or Ultra Rapid Metabolizer(high enzyme levels)|
*CYP2C19 variability depends on ethnicity.