Last reviewed: July 23, 2026 Last updated: July 23, 2026

Written by: Jay Hastings, CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

This article is part of the PlexusDx Education Hub — your resource for evidence-based guidance on precision health. Browse all Precision Health education

Pharmacogenomics — PGx for short — is the study of how your genes affect the way your body processes and responds to medications. It is one of the most established branches of precision health, and it explains a common frustration: the same drug at the same dose can work well for one person and poorly for another. This beginner's guide explains what PGx is and how it differs from the PlexusDx Precision Peptide Genetic Test.

What Pharmacogenomics Is

Traditional prescribing often relies on population averages, which can mean trial and error before the right medication and dose are found. PGx testing analyzes specific genetic variations that influence drug metabolism, aiming to reduce that guesswork. It is a distinct field with its own science and its own dedicated tests — separate from genetic testing focused on nutrition, fitness, or peptide-related pathways.

How Genes Change Drug Metabolism

Most medications are broken down by liver enzymes coded by genes that vary widely. CYP2C19 and CYP2D6 influence how quickly many common drugs are metabolized, classifying people as poor, normal, or rapid metabolizers. VKORC1, TPMT, and DPYD affect specific drug classes. These are the genes pharmacogenomic testing is built around.

What PGx Testing Can and Cannot Do

A pharmacogenomic test, ordered and interpreted with a clinician, can help inform medication and dose decisions and flag adverse-reaction risk for the drugs it covers. It cannot replace clinical judgment or cover every medication. Results are one input among many, which is why PGx belongs in a prescriber's hands.

How PGx Differs From the Precision Peptide Genetic Test

This distinction matters, and PlexusDx states it plainly: PlexusDx does not sell or offer a pharmacogenomic (PGx) test. The PlexusDx Precision Peptide Genetic Test is not a pharmacogenomic test. It does not analyze drug-metabolizing enzymes and does not predict your response to any medication. Instead, it examines peptide-related biological pathways — spanning 14 pathways, 49 peptides, 150+ genetic insights — to offer pathway-level context about your baseline biology. If you want insight into how you metabolize a specific prescription, that is a separate pharmacogenomic conversation to have with your provider. Genetics is a guide, not a guarantee.

Using Genetic Information Responsibly

Whatever genetic testing you pursue, the principle is the same: never start, stop, or change a medication based on a genetic result alone. Bring any report to a qualified healthcare provider or pharmacist who can interpret it in the full context of your care, including your other prescriptions and health history. Used that way, genetic insight turns guesswork into a more informed conversation — genetics is a guide, not a directive.

Frequently Asked Questions

What does PGx testing actually measure?

PGx testing measures genetic variations in drug-metabolizing genes such as CYP2C19, CYP2D6, VKORC1, TPMT, and DPYD. These variants influence how quickly your body processes specific medications, helping a clinician anticipate effectiveness or adverse-reaction risk for the drugs the test covers.

Is the Precision Peptide Genetic Test a pharmacogenomic test?

No. The Precision Peptide Genetic Test is not a pharmacogenomic test and does not predict response to any medication. PlexusDx does not sell a PGx test. The Precision Peptide Genetic Test analyzes peptide-related biological pathways for pathway-level context about your biology. For insight into how you metabolize a specific drug, ask your provider about dedicated pharmacogenomic testing.

Can I change my medications based on a genetic test?

No. Never start, stop, or adjust any medication based on a genetic result alone. Genetic information is one input among many, including your diagnosis, other drugs, and organ function. Always review any report with a qualified healthcare provider or pharmacist before making medication decisions.

Curious about your own peptide-pathway genetics? The Precision Peptide Genetic Test analyzes 14 pathways, 49 peptides, 150+ genetic insights — pathway-level context you can bring to your healthcare provider. It is educational insight into your biology, not a diagnosis, a prescription, or a pharmacogenomic test.

This article is part of the PlexusDx Education Hub. Browse all Precision Health education

PlexusDx does not sell or offer a pharmacogenomic (PGx) test. The Precision Peptide Genetic Test analyzes how your genes influence peptide-related biological pathways. It does not predict response to any specific medication and does not recommend, prescribe, or determine which peptides or drugs you should use. Consult a qualified healthcare provider before making any medication or peptide decision.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. PlexusDx does not offer a pharmacogenomic test. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.