PGx Testing

Introduction to Pharmacogenomic (PGx) Testing

Pharmacogenomics - PGx (Drug-Gene-Disease Testing) plays an important role in identifying respondents and non-respondents to medications, avoiding adverse events, and optimizing drug dose.

Cheek swabs are collected and shipped back using our simple and versatile DNA Collection Kit (shipped to your home address after purchase). 

Comp-PGx, especially, tests for mutations in genes implicated in all important drug-gene interactions. It's Once in a Lifetime test that can help your provider write a targeted prescription in case you are confronted with a serious health event in your lifetime.

Results from a PGx Test can help your provider to determine the following pharmacologic outcomes of drugs prescribed in all important specialties:

  • Adverse Drug Reactions
  • Drug Metabolism
  • Drug Effectiveness
  • Drug Dosage Optimization
  • Drug-Drug Interactions

Private Pay

Buying this kit online is easy. We'll mail the kit to your home address with complete instructions immediately after the purchase. Once we receive your cheek swab, we'll sent the test results to your email ID in a password protected file within 5 business days.

Paid by Insurance:

PGx Tests are covered (once in a lifetime) by all major insurances including Medicare and Medicaid (if ordered by your provider). If you are currently taking one of these medications and have not performed a PGx test before, ask your healthcare provider is this test is right for you? You can download an order form here and take it to your provider. After filling it up completely, your healthcare provider's office will need to fax it to TopBlood at (512) 686-8972. A patient consent form that can be downloaded here is also required. The consent form can be separately emailed to us at Once we receive the documents, we'll mail you the kit to your home address for sample collection. Once we receive your cheek swab, we'll fax the test results to your healthcare provider within 5 business days.

Our PGx tests use a simple cheek swab to test a combination of genes related to the metabolism of drugs used in several conditions.

Single nucleotide polymorphism is a genetic trait exhibited by several Cytochrome P450 (CYP) genes. Genetic variations in these and other genes result in an altered metabolic activity of a wide range of pharmaceutical products implicated in a variety of human disease conditions. This altered metabolic activity leads to drug toxicity.

40–70% of patients exhibit a lack of efficacy of pharmacological treatment or adverse drug reactions due to highly variable in drug response between individuals. CYP enzymes and their roles in drug metabolism have been extensively studied and constitute major determinants of drug response, as they are responsible for 80% of phase 1 drug metabolism and 65–70% of drug clearance.

CYP genes have, therefore, been established as the prime pharmacogenetic biomarkers for drug dosing, efficacy and safety. Since the distribution of these genetic biomarkers vary considerably between the populations, healthcare programs directed toward personalized drug therapy are gaining ground.

FDA recommends getting tested to determine if you have a gene mutation that could render a drug ineffective, cause unwanted side effects or result into a life-threatening event. Based on this information, your healthcare provider can suggest a different drug that can be safer and more effective. 

For further understanding, please refer to the United States FDA recommendations on Pharmacogenomic Biomarkers in Drug Labeling.

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