How to Read Your GeneSight Report: Green, Yellow, and Red Explained

You got your GeneSight report and want to know what it actually means. This guide walks through the color-coded tier system, the metabolizer categories (poor, intermediate, normal, rapid, ultrarapid), and what the report does not cover. If you want pharmacogenetic information on medications outside GeneSight's psychiatric focus, you can often get that from your existing 23andMe or AncestryDNA data without paying for a second test.

GeneSight sorts medications into three categories. Green means 'use as directed': no significant gene-drug interaction based on your genotype, so the medication should behave roughly as expected at standard doses. Yellow means 'moderate gene-drug interaction.' Your genotype may affect how the medication works or how you tolerate it, and your prescriber may want to adjust the dose, monitor more carefully, or consider alternatives. Red is GeneSight's strongest warning that a different medication may work better for you.

The color tier is a summary. It collapses several pieces of information into one category: which genes are involved, what phenotype you have (for example, CYP2C19 poor metabolizer), what the clinical guideline says about dose or substitution, and how strong the evidence is. A yellow classification backed by a strong CPIC recommendation is not the same as a yellow classification backed by softer evidence, but both show up as yellow. For the specific recommendation and how much weight to give it, read the genotype and phenotype details on the page for that medication.

Your GeneSight report will assign you a poor, intermediate, normal, rapid, or ultrarapid metabolizer status for each relevant gene (CYP2D6, CYP2C19, CYP2C9, CYP3A4, CYP1A2, CYP2B6). Any reputable pharmacogenetic test working from the same genotype will arrive at the same phenotype. If you want a second look at the same underlying biology, a service like Gene2Rx can interpret your 23andMe or AncestryDNA data against CPIC guidelines and show you how those phenotypes map to medications outside GeneSight's psychiatric panel.

GeneSight's panel is built for psychiatry. It does not report SLCO1B1 (which affects statin response and muscle pain),^[1] DPYD (important for fluoropyrimidine chemotherapy safety),^[2] TPMT and NUDT15 (needed before azathioprine or mercaptopurine),^[3] UGT1A1 (relevant for irinotecan and nilotinib dosing), or VKORC1 (a main determinant of warfarin dose).^[4] If you take or are considering any medication affected by these genes, GeneSight will not cover it, and a broader pharmacogenetic analysis is worth looking at.

GeneSight's report language is built around metabolizer phenotypes. Here is what each one means in practice, with CPIC-based interpretation that holds up across any pharmacogenetic test.

Your metabolizer phenotype for each gene is a lifelong attribute, anchored to the same CPIC^[7] and FDA^[8] guidelines any pharmacogenetic test uses. Once you know it, the information applies to every current and future medication that gene affects. That is why many patients want a broader pharmacogenetic profile than a psychiatry-focused panel gives them. The same CYP2D6 or CYP2C19 status that guides psychiatric prescribing also matters for pain medications, cardiovascular drugs, and PPIs.

You already did the hard part: you have pharmacogenetic genotype data. Getting a broader interpretation of the same underlying data is the lowest-friction next step for understanding your drug response. If you already have 23andMe or AncestryDNA data (many patients do), a direct-to-consumer pharmacogenetic service can interpret that data against CPIC guidelines across every major drug class.

• Looking for a GeneSight Alternative? Here's the Short Answer
• 23andMe Pharmacogenetics: How to Get a Drug Response Report From Your Existing Data
• AncestryDNA for Drug Testing: Get Pharmacogenetics From Your Ancestry Data
• Looking for a Genomind Alternative? Here's What to Know
• MyHeritage Pharmacogenetics: Use Your MyHeritage DNA for a Drug Response Report
• Nebula Genomics Pharmacogenetics: How to Get a Drug Response Report From Your WGS Data

Yellow means your genotype suggests a moderate gene-drug interaction with that medication. Read the genotype and phenotype details on the medication page to see which gene is involved (usually CYP2D6 or CYP2C19) and what CPIC recommends for that phenotype. Yellow is not a directive to stop the medication. It is a flag that your metabolizer status may affect how well the medication works or how you tolerate it, and your prescriber should know about it when making dose decisions.

CYP2D6 affects plenty of non-psychiatric medications too. Poor metabolizers can run higher-than-expected blood levels on tramadol, metoprolol, amphetamine-based ADHD medications, and tamoxifen. They may also get less effect from codeine because poor metabolizers cannot activate it to its active form. GeneSight will not have said anything about these medications. A broader pharmacogenetic report will.

Your genotype is your genotype. A second test on the same DNA will produce the same metabolizer phenotype. What can be worth getting is a broader interpretation of the same underlying data. If you have 23andMe or AncestryDNA data, a service that interprets it against CPIC guidelines will cover medications GeneSight did not, without requiring a new sample.

Pharmacogenetic testing is one input to prescribing, not the only one. Medication response depends on genetics, drug interactions, adherence, underlying conditions, and ordinary person-to-person variability. A green GeneSight tier just means pharmacogenetics is unlikely to be the reason the medication failed you, so the clinical investigation should focus on other factors.

For most medications it means your metabolizer status sits far enough outside the normal range that standard dosing may need adjustment or closer monitoring. It does not mean the medication is unsafe. Your clinician will use the information to decide whether to start at a lower dose, titrate more slowly, watch for specific side effects, or pick an alternative based on the overall picture.