# Self‐Reported Pharmacogenetic Medication Use in the Our Future Health Cohort

## TL;DR

The study found that 25% of 1.78 million UK participants reported using medications influenced by genetic factors, with many using multiple such drugs at once.

## Contribution

The study quantifies the scale of pharmacogenetic medication use in a large UK cohort and identifies demographic patterns and polypharmacy trends.

## Key findings

- 25.2% of participants reported using at least one pharmacogenetically actionable medication group.
- 37% of users were concurrently exposed to two or more PGx-relevant medications.
- Use of PGx-relevant medications increased with age and was more common in females.

## Abstract

The aim of this study was to describe self‐reported use of medications with established pharmacogenetic guidance in the Our Future Health (OFH) cohort. We examined four key pharmacogenes—CYP2C19, CYP2C9, CYP2D6, and SLCO1B1—and medications supported by strong evidence for clinical actionability according to the Clinical Pharmacogenetics Implementation Consortium (CPIC). Self‐reported medication use was summarized, concurrent use assessed, and findings stratified by age, sex, and ethnicity. We studied these data in 1.78 million OFH participants included in the June 2025 release. The cohort was 57.3% female, aged 18–95 years (mean 53.1 years), with 90.2% self‐identifying as “White.” Eighteen medication groups were explicitly listed in the baseline questionnaire, enabling identification of exposure at group level rather than for individual drugs. Medication groups with pharmacogenetic relevance included antidepressants (selective serotonin reuptake inhibitors and tricyclics), statins, proton pump inhibitors, ibuprofen, opioids, clopidogrel, and warfarin. Overall, 25.2% of participants (N = 449,641) reported use of at least one such group. These users tended to be older, more frequently female, and reported more comorbidities than non‐users. Concurrent exposure to two or more pharmacogenetically actionable medications metabolized by different genes was common, occurring in 37% of users. A substantial proportion of the OFH cohort therefore reported exposure to medications with pharmacogenetic guidance. Use was observed across all ages, with prevalence increasing with age. With continued expansion of the cohort and future linkage to prescribing records, OFH will provide a critical resource for population‐scale pharmacogenetic research.

What is the current knowledge on the topic?
○Genetic variation is a major contributor to differences in drug response, and many commonly prescribed medicines have established pharmacogenetic (PGx) guidance. Population‐based studies have shown that exposure to PGx‐relevant drugs is widespread, increases with age, and often occurs in the context of polypharmacy.
What question did this study address?
○This study examined self‐report use of medications with established PGx guidance by over 1.7 million adults in the Our Future Health cohort, and how this use varies by age, sex, and ethnicity. It also assessed the extent of concurrent use of multiple PGx‐relevant medication groups linked to four key pharmacogenes: CYP2C19, CYP2D6, CYP2C9, and SLCO1B1.
What does this study add to our knowledge?
○The study shows that 25% of participants reported using at least one PGx‐relevant medication and that over one‐third of these individuals reported concurrent use of multiple PGx medication groups. It quantifies the scale of PGx exposure in a large UK cohort and highlights demographic patterns and the frequent involvement of multiple pharmacogenes in routine medication use.
How might this change clinical pharmacology or translational science?
○These findings provide new, large‐scale evidence relevant to decisions concerning single‐ and multi‐gene pharmacogenetic testing and provide population‐level evidence relevant to implementation. The results also establish Our Future Health as a valuable platform for evaluating the impact of pharmacogenetic‐guided prescribing once genetic and prescribing/dispensed data are linked for individual patients.

What is the current knowledge on the topic?
○Genetic variation is a major contributor to differences in drug response, and many commonly prescribed medicines have established pharmacogenetic (PGx) guidance. Population‐based studies have shown that exposure to PGx‐relevant drugs is widespread, increases with age, and often occurs in the context of polypharmacy.

Genetic variation is a major contributor to differences in drug response, and many commonly prescribed medicines have established pharmacogenetic (PGx) guidance. Population‐based studies have shown that exposure to PGx‐relevant drugs is widespread, increases with age, and often occurs in the context of polypharmacy.

What question did this study address?
○This study examined self‐report use of medications with established PGx guidance by over 1.7 million adults in the Our Future Health cohort, and how this use varies by age, sex, and ethnicity. It also assessed the extent of concurrent use of multiple PGx‐relevant medication groups linked to four key pharmacogenes: CYP2C19, CYP2D6, CYP2C9, and SLCO1B1.

This study examined self‐report use of medications with established PGx guidance by over 1.7 million adults in the Our Future Health cohort, and how this use varies by age, sex, and ethnicity. It also assessed the extent of concurrent use of multiple PGx‐relevant medication groups linked to four key pharmacogenes: CYP2C19, CYP2D6, CYP2C9, and SLCO1B1.

What does this study add to our knowledge?
○The study shows that 25% of participants reported using at least one PGx‐relevant medication and that over one‐third of these individuals reported concurrent use of multiple PGx medication groups. It quantifies the scale of PGx exposure in a large UK cohort and highlights demographic patterns and the frequent involvement of multiple pharmacogenes in routine medication use.

The study shows that 25% of participants reported using at least one PGx‐relevant medication and that over one‐third of these individuals reported concurrent use of multiple PGx medication groups. It quantifies the scale of PGx exposure in a large UK cohort and highlights demographic patterns and the frequent involvement of multiple pharmacogenes in routine medication use.

How might this change clinical pharmacology or translational science?
○These findings provide new, large‐scale evidence relevant to decisions concerning single‐ and multi‐gene pharmacogenetic testing and provide population‐level evidence relevant to implementation. The results also establish Our Future Health as a valuable platform for evaluating the impact of pharmacogenetic‐guided prescribing once genetic and prescribing/dispensed data are linked for individual patients.

These findings provide new, large‐scale evidence relevant to decisions concerning single‐ and multi‐gene pharmacogenetic testing and provide population‐level evidence relevant to implementation. The results also establish Our Future Health as a valuable platform for evaluating the impact of pharmacogenetic‐guided prescribing once genetic and prescribing/dispensed data are linked for individual patients.