A GeneSight report organizes psychiatric medications into three color-coded categories based on how your genes may affect each drug. Green means no detected gene-drug interactions. Yellow signals moderate interactions. Red flags significant ones. Understanding what drives those categories, and what the numbered notes beside each medication mean, helps you have a more productive conversation with your prescriber about next steps.
The Three Color Categories
Every medication on your report falls into one of three bins, and the color tells you how much your genetic profile may complicate that drug’s performance in your body.
- Green (“Use as Directed”): No clinically meaningful gene-drug interactions were detected. These medications can be prescribed at standard doses based on your genetic profile alone. Green does not guarantee a medication will work for you, only that your genes are unlikely to interfere with how it’s processed or how it acts.
- Yellow (“Moderate Gene-Drug Interaction”): Your genetic results suggest a possible interaction that could affect drug levels or how the medication works. Your prescriber may still choose a yellow medication but might adjust the dose or monitor you more closely.
- Red (“Significant Gene-Drug Interaction”): Your genes suggest a higher likelihood that the medication will behave differently in your body. That could mean the drug builds up to levels that raise side-effect risk, gets cleared too quickly to be effective, or has a reduced chance of working through its intended mechanism. Red does not mean the medication is dangerous or banned for you. It means your prescriber needs to weigh the interaction carefully and may need to adjust the dose significantly or consider an alternative.
If you’re currently taking a medication that landed in the yellow or red category, don’t stop it on your own. The report is a tool for your prescriber to use alongside your clinical history, current symptoms, and response to treatment so far.
What the Numbered Notes Mean
Next to many medications, you’ll see a small number on the right side of the report. These numbered clinical considerations explain the specific type of gene-drug interaction detected. Here’s what each one tells your prescriber:
- 1: Drug levels in your blood may run too high. Lower doses may be needed.
- 2: Drug levels may run too low. Higher doses may be needed.
- 3: You carry conflicting genetic variations that make it hard to predict the right dose. One gene may push drug levels up while another pulls them down.
- 4: Your genotype may reduce the medication’s effectiveness by altering how it works at the brain level, not just how it’s broken down.
- 6: You have an increased risk of side effects, either because the drug accumulates or because of how it acts on its target.
- 7: Smoking changes how this medication is processed. If you smoke, the report includes a separate “Smokers” section with adjusted results for that drug.
- 8: The FDA’s own prescribing label flags a potential gene-drug interaction for this medication and your genotype.
- 9: The FDA states this medication is contraindicated for your genotype. This is the strongest warning on the report.
- 10: No reliable genetic markers exist yet for this medication, so it can’t be categorized. It appears on the report but without a meaningful recommendation.
Notes 1 and 2 are the most common. They reflect differences in how quickly your liver enzymes break a drug down. Note 4 is different in kind: it’s about the drug’s mechanism of action in the brain, not metabolism. If you see a 4 next to a medication, genetic variation may reduce its ability to do what it’s designed to do regardless of dose.
Your Metabolizer Types
Somewhere on your report, usually on a second page or supplemental section, you’ll find your metabolizer phenotype for each gene tested. The test analyzes six liver enzymes (from the cytochrome P450 family) that handle most psychiatric drug metabolism, plus two genes involved in serotonin signaling that affect how certain antidepressants work at the brain level.
For each liver enzyme gene, you’re classified into one of four categories:
- Ultrarapid metabolizer: You break the drug down faster than average. Medication may clear your system before it has a full effect, potentially requiring higher doses.
- Normal (extensive) metabolizer: Standard metabolism. The drug is expected to behave as the manufacturer intended at typical doses.
- Intermediate metabolizer: Slower-than-average breakdown. Drug levels may be somewhat elevated.
- Poor metabolizer: Much slower breakdown. The drug can accumulate significantly, raising side-effect risk and often requiring lower doses.
One enzyme, CYP1A2, is affected by smoking. On the report, a half-shaded dot next to this gene means your phenotype depends on whether you smoke: smokers are classified as ultrarapid metabolizers for CYP1A2, while nonsmokers with the same genotype are classified as normal. If you quit smoking or start smoking after taking the test, mention it to your prescriber because it changes how certain medications are processed.
Your metabolizer types are permanent genetic traits. They won’t change over time, so this part of the report remains relevant even years later. However, new medications or updated genetic evidence could shift which color category a drug falls into on a future version of the report.
How Metabolism and Brain Genes Differ
The report tests two distinct types of genetic influence, and it helps to understand the difference. Six of the eight genes tested are pharmacokinetic: they control how your liver processes medications. Variations in these genes determine whether a drug builds up too much, gets cleared too fast, or lands in the expected range. Most of the color-coding on the report is driven by these genes.
The other two genes, HTR2A and SLC6A4, are pharmacodynamic. They’re involved in serotonin activity in the brain. HTR2A relates to a serotonin receptor, and variations can increase the risk of adverse effects with certain SSRIs. SLC6A4 relates to the serotonin transporter, and variations can reduce how well an SSRI works or increase the time it takes to respond. When these genes contribute to a yellow or red classification, the clinical consideration number is typically 4 (reduced efficacy) or 6 (increased side-effect risk) rather than 1 or 2.
FDA-Recognized Gene-Drug Interactions
Some of the interactions flagged on your report carry extra weight because the FDA has formally recognized them. For psychiatric medications, the strongest evidence involves CYP2D6 poor metabolizers. If your report shows you’re a CYP2D6 poor metabolizer, several common medications have FDA-backed dosing guidance tied to that status. Aripiprazole, brexpiprazole, and clozapine all build up to higher levels in poor metabolizers, and official labeling recommends dose adjustments. Citalopram in CYP2C19 poor metabolizers has a maximum recommended dose of 20 mg because of increased risk of a heart rhythm issue called QT prolongation.
When you see clinical consideration number 8 or 9, that’s the report pointing you to these FDA-level warnings. Number 9, the contraindication flag, is rare but serious: it means the FDA’s own label says the drug should not be used for your genotype.
What the Report Does Not Tell You
GeneSight results reflect your genetics in isolation. The report does not account for other medications you’re taking, which can speed up or slow down the same liver enzymes and change drug levels independently of your genes. It doesn’t factor in your age, kidney or liver health, body weight, diet, or alcohol use, all of which influence how a drug performs. A medication in your green category could still cause side effects for non-genetic reasons, and a medication in the red category might still be the best clinical choice if the alternatives have been tried and failed.
The test also cannot predict whether a medication will actually relieve your symptoms. It identifies genetic barriers to normal drug processing and some factors that affect drug mechanism, but treatment response involves dozens of biological and environmental variables that no current test can capture. Think of the report as one layer of information, not a prescription. Your prescriber combines it with everything else they know about your history to make treatment decisions.
Medications marked with clinical consideration 10 are a reminder of this limitation: for some drugs, the science simply hasn’t identified reliable genetic markers yet. Those medications appear on the report without a meaningful categorization.
How to Use Your Results Productively
Bring your report to your next appointment and look at it together with your prescriber. Start with any medications you’re currently taking. If a current medication is in the yellow or red bin, check the clinical consideration number to understand why. A “1” next to a red medication, for instance, means your blood levels are likely running high, which might explain side effects you’ve been experiencing. That’s actionable information your prescriber can use to adjust your dose rather than switch drugs entirely.
If you’re starting a new medication, scan the green category first to see which options your genetics are least likely to complicate. But keep in mind that “green” and “best for you” aren’t the same thing. Your prescriber may have strong clinical reasons to choose a yellow medication over a green one based on your diagnosis, symptom profile, or past treatment history.
Your metabolizer phenotypes are worth writing down or keeping accessible in your health records. They apply beyond psychiatric medications. CYP2D6 and CYP2C19, for example, influence how you process certain pain medications, heart drugs, and other prescriptions. Sharing your metabolizer status with any new prescriber gives them a head start on choosing the right drug and dose for you.