CYP2D6 Gene

Cytochrome P450 Family 2 Subfamily D Member 6 (CYP2D6) is a gene involved in drug metabolism that has been studied in relation to immune function, metabolism, and chronic illness. Variants in CYP2D6 may influence how the body responds to infection, inflammation, and long-term recovery.

This page is for educational and informational purposes only. Not a diagnostic tool. Always consult a qualified healthcare provider.

What is the CYP2D6 gene?

CYP2D6 encodes cytochrome p450 family 2 subfamily d member 6, a protein involved in drug metabolism. It belongs to the Metabolism category and is part of the Pharmacogenomics biological cluster. CYP2D6 metabolizes ~25% of all prescription drugs including opioids, antidepressants, antipsychotics, and beta-blockers. Extensive polymorphism creates four phenotypic groups: poor, intermediate, normal, and ultrarapid metabolizers.

Biological role and pathway

CYP2D6 is involved in the drug metabolism pathway, which plays a central role in regulating physiological processes relevant to immune defence, cellular energy, and systemic homeostasis. Genes within the Pharmacogenomics cluster work together to maintain balanced function across interconnected biological systems.

Variants in genes within this pathway may influence an individual's predisposition to altered function in these systems — particularly under conditions of physiological stress such as viral infection or prolonged illness.

CYP2D6 and Long COVID / ME-CFS research

CYP2D6 metabolizer status affects response to antidepressants, tricyclics, and pain medications commonly used in Long COVID symptom management. Poor metabolizers may experience drug toxicity while ultrarapid metabolizers may have treatment failures.

This information is based on published research and does not constitute medical advice. See references below.

Known genetic variants

The following variants (SNPs) in the CYP2D6 gene have been studied in relation to metabolism and chronic illness. Each variant represents a single nucleotide position where individuals may carry different alleles.

Conditions studied in relation to CYP2D6

Research into CYP2D6 variants has explored associations with the following conditions. These are areas of scientific investigation and do not imply that CYP2D6 causes or treats any condition.

Long CovidPharmacokineticsPain ManagementNeurological

Genetic insights from DNA data

Consumer DNA files from 23andMe, AncestryDNA, and MyHeritage contain raw SNP data. When you upload your file to ChronicDNA, the analysis engine checks your genotype against a curated panel of 80+ genes selected for their relevance to Long COVID, ME/CFS, and connected biological pathways - some of which may include CYP2D6 and related genes in the pharmacogenomics pathway.

The report is educational - it explains which variants you carry, what the research says about them, and how they fit into the biological pathways most relevant to chronic illness. Results are presented in plain English with appropriate scientific context, no medical jargon, no scare tactics. All results should be discussed with a qualified healthcare provider.

Related genes in the Pharmacogenomics pathway

CYP2D6 does not act in isolation. The following genes are functionally related and may be analysed together for a more complete picture of your genetic predispositions.

Frequently asked questions

What is the CYP2D6 gene and what does it do?

CYP2D6 (Cytochrome P450 Family 2 Subfamily D Member 6) is involved in drug metabolism. CYP2D6 metabolizes ~25% of all prescription drugs including opioids, antidepressants, antipsychotics, and beta-blockers. Extensive polymorphism creates four phenotypic groups: poor, intermediate, normal, and ultrarapid metabolizers.

How may CYP2D6 gene variants relate to Long COVID or ME/CFS?

CYP2D6 metabolizer status affects response to antidepressants, tricyclics, and pain medications commonly used in Long COVID symptom management. Poor metabolizers may experience drug toxicity while ultrarapid metabolizers may have treatment failures.

Can a DNA test reveal information about my CYP2D6 gene?

Consumer DNA data from 23andMe, AncestryDNA, and MyHeritage includes SNP variants for many genes. ChronicDNA analyses your raw DNA file and reports on variants that have been studied in relation to chronic illness, immune function, and metabolism. This is not a diagnostic service — results are informational and educational only.

Explore your CYP2D6 genetic insights

Upload your DNA data from 23andMe, AncestryDNA, or MyHeritage and receive a personalised report covering >80 genes relevant to Long COVID and ME/CFS.

Get Your Personalised DNA Report

Informational and educational only · Not a diagnostic tool · GDPR compliant

References

The following publications were used in compiling the research context for CYP2D6. This is not an exhaustive literature review.

  • [1]PMID: 25758654
  • [2]Clinical Pharmacology & Therapeutics
  • [3]Nature Reviews Drug Discovery