Yes — the active ingredient is metabolized by a gene known to vary between individuals.
Relevant genes: CYP2D6
Used for: ADHD (non-stimulant option)Gene2Rx covers this medication using the same CPIC and FDA guidelines GeneSight uses, costs $5-$49 instead of several hundred, and works with your existing 23andMe data.
Strattera (atomoxetine) is the most commonly prescribed non-stimulant ADHD medication, often chosen for patients where stimulants are contraindicated or poorly tolerated. It's also the ADHD drug where pharmacogenetics can be most clinically useful, because atomoxetine is cleared almost entirely by CYP2D6. Poor metabolizers have plasma concentrations roughly ten times higher than normal metabolizers at the same dose, which means they reach therapeutic effect at lower doses, but also that side effects like appetite loss, gastrointestinal upset, and elevated heart rate appear more often. The FDA label for Strattera includes specific dose adjustments for CYP2D6 poor metabolizers.
Atomoxetine plasma levels vary enormously across CYP2D6 phenotypes. The FDA recommends starting poor metabolizers at the standard 40 mg daily but holding there longer (at least 4 weeks) before considering increases, because side effects develop more predictably at the elevated plasma levels that result. For ultrarapid metabolizers, the opposite problem: reaching therapeutic plasma levels may require doses at or near the maximum daily limit (80 to 100 mg), and some patients simply don't respond adequately to atomoxetine and are better served by a different class.
Read the full atomoxetine genetics guide →Published guidance from CPIC and FDA on how atomoxetine should be dosed or substituted based on your CYP2D6 phenotype.
| Phenotype | What it means | Recommendation | Evidence |
|---|---|---|---|
|
Ultrarapid Metabolizer
CYP2D6
|
Your body clears this medicine very quickly, so you may need a higher dose to get the right effect. |
CPIC
Initiate with a dose of 40 mg/day and increase to 80 mg/day after 3 days. If no clinical response and in the absence of adverse events after 2 weeks, consider increasing dose to 100 mg/day. If no clinical response observed after 2 weeks, consider obtaining a peak plasma concentration (1 to 2 hours after dose administered). If <200 ng/ml, consider a proportional increase in dose to approach 400 ng/ml.e,f Dosages greater than 100 mg/day may be needed to achieve target concentrations.
FDA
Initiate therapy with recommended starting dose.
|
Moderate |
|
Normal Metabolizer
CYP2D6
|
You may need a higher dose or monitoring if the medication isn’t working well. |
CPIC + CPIC + CPIC + CPIC
Initiate with a dose of 40 mg/day and increase to 80 mg/day after 3 days. If no clinical response and in the absence of adverse events after 2 weeks, consider increasing dose to 100 mg/day. If no clinical response observed after 2 weeks, consider obtaining a peak plasma concentration (1 to 2 hours after dose administered). If <200 ng/ml, consider a proportional increase in dose to approach 400 ng/ml.e,f Dosages greater than 100 mg/day may be needed to achieve target concentrations.
FDA
Initiate therapy with recommended starting dose.
|
Moderate |
|
Intermediate Metabolizer
CYP2D6
|
Your body processes this drug more slowly, so you may need lower doses or careful adjustments. |
CPIC + CPIC + CPIC + CPIC
Initiate with a dose of 40 mg/day and if no clinical response and in the absence of adverse events after 2 weeks increase dose to 80 mg/day. If response is inadequate after 2 weeks consider obtaining a plasma concentration 2-4 h after dosing. If concentration is <200 ng/ml, consider a proportional dose increase to achieve a concentration to approach 400 ng/ml.e,f If unacceptable side effects are present at any time, consider a reduction in dose.
FDA
Initiate therapy with recommended starting dose.
|
Moderate |
|
Poor Metabolizer
CYP2D6
|
Your body processes this drug very slowly, so you may need a lower dose and close monitoring to avoid side effects. |
CPIC
Initiate with a dose of 40 mg/day and if no clinical response and in the absence of adverse events after 2 weeks increase dose to 80 mg/day. If response is inadequate after 2 weeks consider obtaining a plasma concentration 2-4 h after dosing. If concentration is <200 ng/ml, consider a proportional dose increase to achieve a concentration to approach 400 ng/ml.e,f If unacceptable side effects are present at any time, consider a reduction in dose.
FDA
Extend titration interval and only increase dose if tolerated. Refer to FDA labeling for specific dosing adjustments.
|
Strong |
|
Indeterminate
CYP2D6
|
The impact of your genotype on response to this drug is unknown. |
CPIC + FDA
Initiate therapy with recommended starting dose.
|
— |
|
Not available
CYP2D6
|
The impact of your genotype on response to this drug is unknown. |
CPIC + FDA
Initiate therapy with recommended starting dose.
|
— |
CYP2D6 is the most clinically important pharmacogene. It metabolizes around a quarter of all prescription drugs, including many antidepressants, opioids, and stimulants. The gene is unusually variable: roughly 7 percent of people are poor metabolizers (they barely activate CYP2D6), and another 1 to 3 percent are ultrarapid metabolizers (their enzyme is overactive).
For most CYP2D6 drugs, poor metabolizers feel stronger effects and more side effects at standard doses, while ultrarapid metabolizers may feel almost nothing. For prodrugs like codeine, the relationship flips: poor metabolizers feel less effect because they can't activate the drug.
Strattera is often tried when a patient wants to avoid stimulants or has a history that makes stimulants risky (anxiety, cardiac concerns, substance use). CYP2D6 testing makes atomoxetine dosing a much cleaner conversation: it tells you up front whether you're likely to need a low starting dose and slow titration (poor metabolizer) or whether you may need to push toward the upper dose range to feel any effect (ultrarapid metabolizer). Either way, it's information your prescriber can use.
Unlike stimulants (which work within an hour of the first dose), atomoxetine requires steady-state plasma levels that take 2 to 4 weeks to build up. A CYP2D6 poor metabolizer may feel effects sooner because plasma levels rise faster, while an ultrarapid metabolizer may feel nothing until week 6 or 8 at a higher dose. That disconnect between dose timing and apparent response is one of the reasons knowing CYP2D6 phenotype up front is helpful.
The same gene (CYP2D6), but the interpretation is slightly different because the drugs are so different in structure and effect profile. Both are cleared by CYP2D6, so a poor metabolizer will have elevated plasma levels of either. For Adderall, that translates to stronger stimulant effects. For Strattera, it translates to more non-stimulant side effects (nausea, fatigue, heart rate elevation) at the same dose.
No, not by itself. Many poor metabolizers take Strattera successfully at standard doses. The practical advice is usually to titrate more slowly and to not push the dose up reflexively if initial effects seem strong. Talk to your prescriber rather than changing the regimen on your own.
This page describes the general pharmacogenetics. A Gene2Rx report analyzes your own DNA to tell you which metabolizer group you fall into, across every medication.
Get your report Look up another medicationInformational only — not medical advice. Pharmacogenetic guidance describes population-level patterns; your individual response depends on many factors. Never start, stop, or change a medication without talking to your prescribing clinician.