Atomoxetine

What it is

Atomoxetine is a prescription non-stimulant medicine for attention-deficit/hyperactivity disorder, taken as a capsule once or twice a day. Unlike methylphenidate and the amphetamines it is not a controlled substance in the United States. It is a selective inhibitor of the norepinephrine transporter and is broken down mainly by the liver enzyme CYP2D6, which means people with little or no CYP2D6 activity reach much higher blood levels.

What the research says

The randomised evidence shows a real but moderate reduction in ADHD symptoms on clinician ratings in both children and adults, smaller than amphetamines in the same network meta-analysis. The same analysis found that on teachers' ratings, atomoxetine was not shown to beat placebo. It carries a boxed warning for suicidal thoughts and behaviour in children, based on a 0.4% versus 0% difference in short-term trials, and separate postmarketing reports of rare but severe liver injury. It is not habit-forming and needs no taper.

Evidence grade: Well established.

How it works

Drug class: Selective norepinephrine (noradrenaline) reuptake inhibitor; non-stimulant ADHD medicine; not a controlled substance

Nerve cells release noradrenaline into the gap between cells, then pull it back in through a protein called the norepinephrine transporter. Atomoxetine blocks that transporter, so noradrenaline stays in the gap longer. The label is explicit that exactly how this improves ADHD is not known. (Source 1)

Boxed warning

All STRATTERA-treated pediatric patients 6 years of age or older should be monitored and observed closely for suicidal thoughts and behavior, clinical worsening, or unusual changes in behavior, especially during the initial months of therapy or at times of dosage changes. Families and caregivers should be advised of the need for close observation and communication with the health care provider. Consider stopping STRATTERA in patients who experience emergent suicidal thoughts and behavior [see Warnings and Precautions (5.1)].

(Source 2)

What it is used for

• In the largest network meta-analysis of ADHD drugs, atomoxetine beat placebo on clinician-rated core symptoms in both children and adolescents (SMD -0.56) and adults (SMD -0.45), but on teachers' ratings it was not shown to beat placebo. It was also less well tolerated than placebo in adults. A 2025 systematic review of six trials found it comparable to methylphenidate. Evidence: established. (Source 3)
• A meta-analysis of three placebo-controlled trials in 241 children found benefit on parent-rated hyperactivity (SMD -0.73) and inattention (SMD -0.53), with the authors stating the magnitude of the effect is uncertain and that more trials are needed. Evidence: limited. (Source 4)

Interactions

• Monoamine oxidase inhibitors, including linezolid and intravenous methylene blue (case reports): Serious and sometimes fatal reactions have been reported, with fever, rigidity, unstable vital signs and severe agitation. The combination is contraindicated, including within 14 days of stopping an MAOI. (Source 5)
• Strong CYP2D6 inhibitors (for example paroxetine, fluoxetine, quinidine) (pharmacokinetic study): Atomoxetine is broken down by CYP2D6, so blocking that enzyme raises atomoxetine levels in the blood. The label responds by lengthening the dose titration interval. (Source 6)
• Oral albuterol (salbutamol) and other systemic beta2 agonists (pharmacokinetic study): Atomoxetine can amplify the heart-rate and blood-pressure effects of systemically given albuterol. (Source 7)
• Food (label): Food does not require any change: the label states atomoxetine may be taken with or without food. Capsules must be swallowed whole rather than opened, because the contents irritate the eye. (Source 8)
• Antihypertensive drugs and other drugs that raise blood pressure (label): Because atomoxetine itself raises blood pressure and heart rate, combining it with pressor drugs or using it alongside blood-pressure treatment calls for more frequent monitoring. (Source 9)

Stopping it

• Atomoxetine does not need to be tapered. The U.S. label states plainly that no taper is needed when stopping it, and cross-references the drug abuse and dependence sections. (Source 10)
• There is no recognised atomoxetine withdrawal syndrome: section 9.3 of the label reports no evidence of symptom rebound or discontinuation reactions after stopping. (Source 11)
• In a 25-week randomised withdrawal study in adults, the blood-pressure and heart-rate rises caused by atomoxetine returned to baseline after it was stopped, and common side effects took a median of 3 to 53 days to resolve, with male sexual side effects among the slowest. (Source 12)
• Stopping is also the required response to signs of liver injury: the label says atomoxetine should be discontinued and not restarted in patients with jaundice or laboratory evidence of liver injury. (Source 13)
• Stopping atomoxetine does not clear the way for an MAOI antidepressant straight away. The label requires at least 14 days to pass after stopping atomoxetine before an MAOI is started, and the same 14 days in the other direction before atomoxetine is started. (Source 14)

What goes wrong

The boxed warning states that atomoxetine increased the risk of suicidal ideation in children and adolescents aged 6 and over with ADHD in short-term studies. (Source 2)

• Official position, Certainty not rated.
• Size: not applicable.
• Who: Pediatric patients 6 years of age and older treated with atomoxetine.
• How long: not applicable.
• Result: No rate appears in the boxed warning itself; it is a regulatory position on the label dated 30 June 2026.
• Funding: not stated.

STRATTERA increased the risk of suicidal ideation in pediatric patients aged 6 years

The pooled trial data behind the boxed warning show suicidal ideation in 0.4% (5 of 1,357) of children on atomoxetine against 0% (0 of 851) on placebo, an absolute difference of about 0.4 percentage points, with no suicides; all five cases were in 6- to 12-year-olds and all in the first month. (Source 15)

• Meta-analysis, Moderate certainty.
• Size: 12 studies, over 2,200 pediatric patients (1,357 on atomoxetine, 851 on placebo)
• Who: Children and adolescents 6 years and older, 11 studies in ADHD and 1 in another population.
• How long: short-term, 6 to 18 weeks.
• Result: Suicidal ideation 0.4% (5/1,357) vs 0% (0/851); number needed to harm roughly 270; no completed suicides; the same analysis in adults did not show increased risk.
• Funding: not stated (manufacturer's pooled trial analysis reproduced on the label)

STRATTERA increased the risk of suicidal ideation in pediatric patients 6 years and older with ADHD in pooled placebo-controlled short-term studies (6 to 18 weeks). In 12 studies (11 studies in patients with ADHD and 1 study in another population) with over 2,200 pediatric patients, the mean incidence of suicidal ideation in STRATTERA-treated pediatric patients was 0.4% (5/1,357) (including one patient with a suicide attempt) compared to 0% (0/851) in placebo-treated pediatric patients. No suicides occurred in these studies.

Severe liver injury is a rare postmarketing harm: no liver injury appeared in trials of about 6,000 patients, but rare cases of clinically significant injury and of liver failure, including one needing a transplant, have been reported after marketing. (Source 13)

• Case series, Low certainty.
• Size: clinical trials of about 6,000 patients; postmarketing reports.
• Who: People taking atomoxetine.
• How long: liver injury reported within 120 days of starting in most cases.
• Result: No rate can be calculated from spontaneous reports; one reported case recurred on rechallenge with enzymes up to 40 times the upper limit of normal.
• Funding: not stated.

Although no evidence of liver injury was detected in clinical trials of about 6,000 patients, there have been rare cases of clinically significant liver injury that were considered probably or possibly related to STRATTERA use during postmarketing use: Rare cases of liver failure have been reported during postmarketing use, including a case that resulted in a liver transplant.

A manufacturer review of its own safety databases judged three spontaneously reported liver injuries probably caused by atomoxetine, one with a positive rechallenge, out of 351 liver-related reports in four years. (Source 16)

• Case series, Low certainty.
• Size: 7,961 trial patients plus 351 postmarketing liver-related reports.
• Who: Paediatric and adult patients taking atomoxetine.
• How long: first 4 years after launch in 2002.
• Result: 41 of 7,961 trial patients had hepatobiliary events, mostly mild ALT/AST rises; none met Hy's law; of 282 assessable postmarketing cases, 3 were judged probably drug-related and all three recovered on stopping.
• Funding: industry (review of the Eli Lilly and Company atomoxetine databases by company physicians)

Of 7961 paediatric and adult patients treated with atomoxetine in clinical trials, 41 were identified as having hepatobiliary events requiring additional analysis. Most of these events were mild increases in ALT and AST levels. None of these cases met Hy's rule criteria or progressed to liver failure.

In adults, atomoxetine was less well tolerated than placebo: more people dropped out because of side effects. (Source 3)

• Meta-analysis, Low certainty.
• Size: tolerability analysis based on 11,018 children and adolescents and 5,362 adults.
• Who: Adults with ADHD in double-blind randomised trials.
• How long: about 12 weeks.
• Result: Dropout due to side-effects odds ratio 2.33 (95% CI 1.28 to 4.25) in adults; methylphenidate 2.39 (1.40 to 4.08); the effect was not seen in children and adolescents for atomoxetine.
• Funding: independent (Stichting Eunethydis and UK NIHR)

and atomoxetine (2·33, 1·28-4·25), methylphenidate (2·39, 1·40-4·08), and modafinil (4·01, 1·42-11·33) were less well tolerated than placebo in adults only.

Treatment-stopping side effects were about twice as common on atomoxetine as on placebo in short-term paediatric trials. (Source 17)

• Randomized trial, Moderate certainty.
• Size: 1,613 atomoxetine and 945 placebo pediatric patients.
• Who: Children and adolescents 6 years and older with ADHD.
• How long: acute placebo-controlled studies.
• Result: Discontinuation for an adverse reaction 3% (48/1,613) on atomoxetine vs 1.4% (13/945) on placebo, an absolute excess of about 1.6 percentage points; the reactions reported by more than one patient were irritability and somnolence (0.3%, N=5 each), aggression, nausea, vomiting and abdominal pain (0.2%, N=4 each), and constipation, fatigue, feeling abnormal and headache (0.1%, N=2 each)
• Funding: not stated (manufacturer trial data reproduced on the label)

In the acute placebo-controlled studies of pediatric patients 6 years of age and older with ADHD, 3% (48/1,613) of STRATTERA-treated pediatric patients and 1.4% (13/945) of placebo-treated pediatric patients discontinued due to an adverse reaction. Among STRATTERA-treated patients, irritability (0.3%, N=5); somnolence (0.3%, N=5); aggression (0.2%, N=4); nausea (0.2%, N=4); vomiting (0.2%, N=4); abdominal pain (0.2%, N=4); constipation (0.1%, N=2); fatigue (0.1%, N=2); feeling abnormal (0.1%, N=2); and headache (0.1%, N=2) were the reasons for discontinuation reported by more than one patient.

Tachycardia was reported three times as often on atomoxetine as on placebo in adult trials and in 0.3% versus 0% of paediatric patients. (Source 18)

• Randomized trial, Moderate certainty.
• Size: 1,597 atomoxetine and 934 placebo pediatric patients; 540 atomoxetine and 402 placebo adults.
• Who: Children, adolescents and adults with ADHD in placebo-controlled studies.
• How long: short-term placebo-controlled studies.
• Result: Pediatric tachycardia 0.3% (5/1,597) vs 0% (0/934); adult tachycardia 1.5% (8/540) vs 0.5% (2/402)
• Funding: not stated (manufacturer trial data reproduced on the label)

In placebo-controlled studies of pediatric patients 6 years of age and older with ADHD, tachycardia was identified as an adverse reaction in 0.3% (5/1,597) of STRATTERA-treated patients compared with 0% (0/934) of placebo-treated patients.

Children on atomoxetine lost weight over nine weeks while children on placebo gained it, gained less height, and the proportion losing at least 3.5% of body weight rose steeply with dose. (Source 19)

• Randomized trial, Moderate certainty.
• Size: not stated for the pooled short-term analysis.
• Who: Pediatric patients with ADHD in short-term placebo-controlled studies.
• How long: up to 9 weeks.
• Result: Atomoxetine: average 0.4 kg weight loss and 0.9 cm height gain; placebo: 1.5 kg weight gain and 1.1 cm height gain, a difference of about 1.9 kg in weight over 9 weeks. In a fixed-dose trial, the proportion losing at least 3.5% of body weight rose with dose: 1.3% on placebo, 7.1% at 0.5 mg/kg/day, 19.3% at 1.2 mg/kg/day and 29.1% at 1.8 mg/kg/day.
• Funding: not stated (manufacturer trial data reproduced on the label)

In short-term, placebo-controlled studies (up to 9 weeks), STRATTERA-treated patients lost an average of 0.4 kg in weight and gained an average of 0.9 cm in height, compared to a gain of 1.5 kg in weight and 1.1 cm in height in the placebo-treated patients. In a fixed-dose controlled trial, 1.3%, 7.1%, 19.3%, and 29.1% of patients in the placebo, 0.5, 1.2, and 1.8 mg/kg/day STRATTERA groups, respectively, lost at least 3.5% of their body weight.

People who are CYP2D6 poor metabolisers reach roughly tenfold higher atomoxetine exposure, which the label links to a higher risk of adverse reactions. (Source 20)

• Blood level study, Moderate certainty.
• Size: not stated in the pharmacogenomics section.
• Who: People with two nonfunctional CYP2D6 alleles compared with other metabolizer types.
• How long: not applicable.
• Result: AUC approximately 10-fold higher and Css,max approximately 5-fold higher in CYP2D6 poor metabolizers.
• Funding: not stated (manufacturer data reproduced on the label)

Atomoxetine AUC was approximately 10-fold higher and atomoxetine Css, max was approximately 5-fold higher in CYP2D6 poor metabolizers compared to other CYP2D6 metabolizer types

The U.S. label directs that patients be screened for a personal or family history of bipolar disorder, mania or hypomania before atomoxetine is started, because of the risk of activating a manic episode. (Source 21)

• Official position, Certainty not rated.
• Size: Not applicable (regulatory position)
• Who: Anyone being considered for atomoxetine.
• How long: Before initiation.
• Result: No incidence figure is given in this section; the label cross-references its warning on activation of mania or hypomania.
• Funding: not stated (U.S. prescribing information)

Prior to initiating treatment with STRATTERA, screen patients for a personal or family history of bipolar disorder, mania, or hypomania [see Warnings and Precautions (5.6)].

What the evidence supports

Atomoxetine reduced clinician-rated ADHD core symptoms more than placebo in both children and adults, but by less than amphetamines in the same analysis. (Source 3)

• Meta-analysis, Low certainty.
• Size: 133 double-blind randomised trials; efficacy analysis at about 12 weeks based on 10,068 children and adolescents and 8,131 adults.
• Who: Children, adolescents and adults with ADHD.
• How long: timepoints closest to 12 weeks; the authors found insufficient data for 26 and 52 weeks.
• Result: Children and adolescents, clinician-rated SMD -0.56 (95% CI -0.66 to -0.45); adults SMD -0.45 (95% CI -0.58 to -0.32); amphetamines SMD -1.02 (-1.19 to -0.85) and methylphenidate -0.78 (-0.93 to -0.62) in children.
• Funding: independent (Stichting Eunethydis and the UK National Institute for Health Research Oxford Health Biomedical Research Centre)

For ADHD core symptoms rated by clinicians in children and adolescents closest to 12 weeks, all included drugs were superior to placebo (eg, SMD -1·02, 95% CI -1·19 to -0·85 for amphetamines, -0·78, -0·93 to -0·62 for methylphenidate, -0·56, -0·66 to -0·45 for atomoxetine).

A 2025 systematic review of six comparative studies found atomoxetine comparable in effect to methylphenidate in children and adolescents, with nausea, fatigue and appetite change the commonest adverse effects. (Source 22)

• Systematic review, Low certainty.
• Size: 6 studies, 905 participants.
• Who: Children and adolescents aged 6 to 16 with ADHD.
• How long: not stated; the authors call for long-term studies.
• Result: No pooled effect size reported; the review reports comparable symptom reduction to methylphenidate.
• Funding: not stated.

The six included studies involved a total of 905 participants. Atomoxetine demonstrated comparable efficacy to methylphenidate in reducing ADHD symptoms. The most common adverse effects were nausea, fatigue, and appetite changes.

In children with autism and ADHD, atomoxetine improved parent-rated hyperactivity and inattention, but the reviewers said the magnitude of the effect is uncertain. (Source 4)

• Meta-analysis, Low certainty.
• Size: 3 randomised placebo-controlled trials, 241 children.
• Who: Children and adolescents with autism spectrum disorder and ADHD symptoms.
• How long: not stated in the abstract.
• Result: Parent-rated hyperactivity SMD -0.73 (95% CI -1.15 to -0.34); parent-rated inattention SMD -0.53 (95% CI -0.93 to -0.12)
• Funding: not stated.

Atomoxetine had a benefit on improving parent-rated hyperactivity (standardized mean difference [SMD] = -0.73, 95% Confidence Interval, CI = -1.15 to -0.34) and parent-rated inattention (SMD = -0.53, 95% CI = -0.93 to -0.12) but the magnitude of effects is uncertain.

What the evidence does not support

On teachers' ratings, the rater group furthest from the prescriber, atomoxetine was not shown to be more effective than placebo; only methylphenidate and modafinil were. (Source 3)

• Meta-analysis, Low certainty.
• Size: 133 double-blind randomised trials; teacher-rated comparisons were available for a subset.
• Who: Children and adolescents with ADHD.
• How long: timepoints closest to 12 weeks.
• Result: Methylphenidate SMD -0.82 (95% CI -1.16 to -0.48) and modafinil -0.76 (-1.15 to -0.37) beat placebo on teachers' ratings; atomoxetine was not among the drugs shown to do so.
• Funding: independent (Stichting Eunethydis and UK NIHR)

By contrast, for available comparisons based on teachers' ratings, only methylphenidate (SMD -0·82, 95% CI -1·16 to -0·48) and modafinil (-0·76, -1·15 to -0·37) were more efficacious than placebo.

An independent meta-analysis of 32 placebo-controlled atomoxetine trials found the excess of suicidal behaviour or ideation was not statistically significant, which tempers the boxed warning without removing it. (Source 23)

• Meta-analysis, Moderate certainty.
• Size: 3,883 pediatric and 3,365 adult patients.
• Who: Children, adolescents and adults with ADHD in double-blind placebo-controlled trials.
• How long: acute phases of 23 pediatric and 9 adult trials completed 1998 to 2011.
• Result: Combined suicidal behaviour or ideation 0.37% vs 0.07% placebo in children, MHRR 1.57, p=0.42; 0.11% vs 0.12% in adults, MHRR 0.96, p=0.96; suicidal ideation alone in children MHRR 1.63, p=0.41.
• Funding: not stated (authors include manufacturer-affiliated investigators; the data are the manufacturer's trial database)

The frequency of combined suicidal behavior or ideation with atomoxetine treatment was 0.37% in pediatric patients (vs. 0.07% with placebo) and 0.11% in adults (vs. 0.12% with placebo) and the risk compared with placebo was not statistically significant (MHRR=1.57; p=0.42 and MHRR=0.96; p=0.96, respectively). In pediatric patients, suicidal ideation only was reported more frequently compared with placebo (MHRR=1.63; p=0.41).

In a 279,315-patient Medicaid cohort, starting atomoxetine rather than a stimulant was not associated with more suicidal events, though the confidence interval was wide. (Source 24)

• Cohort study, Low certainty.
• Size: 279,315 patients in the first-line cohort and 220,215 in the second-line cohort.
• Who: Medicaid patients aged 5 to 18 starting ADHD treatment, 2002 to 2006.
• How long: first year of follow-up.
• Result: Adjusted hazard ratio 0.95 (95% CI 0.47 to 1.92, P=0.88) first-line; 0.71 (95% CI 0.30 to 1.67, P=0.43) second-line.
• Funding: independent (NCATS NIH)

The first-line treatment cohort included 279 315 patients. During the first year of follow-up, the adjusted hazard ratio for current atomoxetine use compared with current stimulant use was 0.95 (95% CI 0.47-1.92, P = .88). The second-line treatment cohort included 220 215 patients. During the first year of follow-up, the adjusted hazard ratio for current atomoxetine use compared with current stimulant use was 0.71 (95% CI 0.30-1.67, P = .43).

In a randomised placebo-controlled abuse-potential study in adults, atomoxetine showed no stimulant or euphoriant properties, and across large trial programmes only isolated incidents of inappropriate self-administration were seen. (Source 25)

• Randomized trial, Low certainty.
• Size: One randomised abuse-potential study in adults, plus clinical study data in over 2,000 adults and pediatric patients with ADHD and over 1,200 adults with depression.
• Who: Adults in the abuse-potential study; adults and children with ADHD, and adults with depression, in the pooled trial data.
• How long: Not stated.
• Result: No quantified abuse-liability measure is given on the label; the stated outcome is absence of stimulant or euphoriant properties and only isolated incidents of inappropriate self-administration.
• Funding: not stated (manufacturer trial data reproduced on the label)

In a randomized, double-blind, placebo-controlled, abuse-potential study in adults that compared effects of STRATTERA and placebo, STRATTERA was not associated with stimulant or euphoriant properties. Clinical study data in over 2,000 adults and pediatric patients with ADHD and over 1,200 adults with depression (STRATTERA is not indicated for the treatment of depression) showed only isolated incidents of inappropriate STRATTERA self-administration.

Where the evidence is mixed

The certainty of the network meta-analysis estimates was not uniformly high; the authors rated confidence as low or very low for most indirect comparisons. (Source 3)

• Meta-analysis, Low certainty.
• Size: 133 double-blind randomised trials.
• Who: Children, adolescents and adults with ADHD.
• How long: about 12 weeks.
• Result: No single effect size; this is the authors' GRADE assessment of their own network.
• Funding: independent (Stichting Eunethydis and UK NIHR)

The confidence of estimates varied from high or moderate (for some comparisons) to low or very low (for most indirect comparisons).

Where the research disagrees

Whether atomoxetine really increases suicidal thinking in children enough to warrant a boxed warning

• U.S. prescribing information for STRATTERA (Eli Lilly and Company), label dated 30 June 2026, regulatory position based on pooled short-term placebo-controlled trials: STRATTERA increased the risk of suicidal ideation in pediatric patients aged 6 years (Source 2)
• Bangs and colleagues, meta-analysis of 32 placebo-controlled atomoxetine trials (2014), meta-analysis of 3,883 pediatric and 3,365 adult trial participants: the risk compared with placebo was not statistically significant (MHRR=1.57; p=0.42 and MHRR=0.96; p=0.96, respectively) (Source 23)
• Linden and colleagues, Medicaid cohort study (2016), retrospective propensity-score-adjusted cohort of 279,315 patients: First- and second-line treatment of youths age 5 to 18 with atomoxetine compared with stimulants was not significantly associated with an increased risk of suicidal events. The low incidence of suicide and suicide attempt resulted in wide confidence intervals (Source 26)

Whether atomoxetine should be a first-choice ADHD medicine

• Cortese and colleagues, network meta-analysis of 133 trials (2018), systematic review and network meta-analysis: Taking into account both efficacy and safety, evidence from this meta-analysis supports methylphenidate in children and adolescents, and amphetamines in adults, as preferred first-choice medications for the short-term treatment of ADHD. (Source 27)
• Authors of a 2025 systematic review of atomoxetine in children and adolescents, systematic review of 6 studies, 905 participants: Atomoxetine demonstrated comparable efficacy to methylphenidate in reducing ADHD symptoms. (Source 22)

How much

• Reference intake: There is no reference intake for a prescription medicine; the dose is set by the prescriber and titrated. As a position, the U.S. label dated 30 June 2026 states that no additional benefit has been demonstrated above 1.2 mg/kg/day in patients under 70 kg. (Source 28)
• Upper limit: No tolerable upper intake level exists. The U.S. label dated 30 June 2026 states a maximum of 100 mg/day and says there is no data supporting greater effectiveness above that. (Source 28)
• Studied: A 25-week randomised withdrawal study used 40 to 100 mg/day open-label for 12 weeks, then 80 or 100 mg/day double-blind for 12 weeks before randomisation. (Source 29)
• Studied: The label states atomoxetine may be taken with or without food, and the capsules are to be swallowed whole. (Source 8)
• Studied: The label's exposure-response analysis compared atomoxetine 0.5, 1.2 or 1.8 mg/kg/day against placebo. (Source 30)

A common belief, and what the research shows

The belief: Because atomoxetine is not a stimulant and not a controlled substance, it is the gentler, safer choice.

What the research shows: Not being a controlled substance is real: the label states "STRATTERA contains atomoxetine which is not a controlled substance." and "After STRATTERA discontinuation, there was no evidence of symptom rebound or adverse reactions suggesting a STRATTERA-discontinuation or withdrawal syndrome." But gentler is not the same as safer. Atomoxetine is the ADHD drug carrying a boxed warning for suicidal thoughts in children, it has caused rare liver failure, and in the largest network meta-analysis it was less well tolerated than placebo in adults: "and atomoxetine (2·33, 1·28-4·25), methylphenidate (2·39, 1·40-4·08), and modafinil (4·01, 1·42-11·33) were less well tolerated than placebo in adults only."

Questions and answers

What is it?

Atomoxetine is a prescription capsule for ADHD in adults and in children aged 6 and over. It is a non-stimulant: in the United States it is not a controlled substance, unlike methylphenidate or the amphetamines. It is approved as part of a wider treatment programme that may also include psychological, educational and social measures. (Source 31)

What does it do in the body?

It blocks the protein that pulls noradrenaline back into nerve cells, so noradrenaline lingers longer in the gap between them. The label is candid that the precise mechanism by which this improves ADHD is unknown, and that the inference comes from laboratory uptake and neurotransmitter-depletion studies rather than from human brain measurements. (Source 1)

Is it good or bad for you?

Both, depending on who takes it. In the largest network meta-analysis it reduced clinician-rated ADHD symptoms more than placebo in children (SMD -0.56) and adults (SMD -0.45), although it did not beat placebo on teachers' ratings and was less well tolerated than placebo in adults. Against that, it carries a boxed warning for suicidal thoughts in children, with suicidal ideation in 0.4% on drug versus 0% on placebo in short-term trials, and rare postmarketing liver failure. (Source 3)

How do you get more of it?

Atomoxetine is available only on prescription; it is not a nutrient and there is no dietary or over-the-counter route to it. The prescriber sets and titrates the dose. As a position, the U.S. label dated 30 June 2026 states that no additional benefit has been demonstrated above 1.2 mg/kg/day in people under 70 kg, and that there is no data supporting better effectiveness above 100 mg/day. These are label positions, not advice for anyone. (Source 28)

If it is harmful, what reduces it?

If atomoxetine is causing harm, it is simply stopped; there is no taper and no withdrawal syndrome, and in the randomised withdrawal study the blood-pressure and heart-rate rises it caused returned to baseline once it was stopped. Side effects took a median of 3 to 53 days to resolve, so some persist for weeks after the last capsule. Stopping is mandatory, and restarting is ruled out, if there is jaundice or laboratory evidence of liver injury. (Source 13)

Why might someone be low in it or missing it?

Nobody is naturally short of atomoxetine. What varies enormously is how much of a given dose reaches the bloodstream, because the drug is cleared by the CYP2D6 enzyme. People with two non-working CYP2D6 genes have roughly tenfold higher exposure, and drugs that block CYP2D6 raise levels the same way; people with fast CYP2D6 clear it quickly. Skipped doses matter too, because the effect builds over weeks rather than hours. (Source 20)

Which whole foods contain it or feed it?

No whole food contains atomoxetine; it is a synthetic molecule available only on prescription. Food does not interfere with it either: the label states it may be taken with or without food. The capsules must be swallowed whole and not opened. No documented food or supplement interaction specific to atomoxetine was found in the sources searched for this write-up. (Source 8)

What happens if you do not have it?

Not taking atomoxetine is the normal state for almost everyone, and stopping it causes no withdrawal reaction. For someone with ADHD who stops, what returns is the untreated condition; in the 25-week randomised withdrawal study, responders were re-randomised to atomoxetine or placebo precisely to measure that. The physiological effects of the drug, including its blood-pressure and heart-rate rises, reverse. (Source 32)

How can you test for it?

Atomoxetine blood levels are not routinely measured, and there is no test to diagnose ADHD or to confirm the drug is working. The one laboratory test the label does describe is CYP2D6 genotyping, which identifies poor metabolisers who reach much higher drug exposure and in whom the label lengthens the titration interval. Liver enzyme and function tests are used reactively, at the first sign of liver trouble, not as routine screening. (Source 33)

References

1. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 12.1 Mechanism of Action. 2026. Read the source
2. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - BOXED WARNING section. 2026. Read the source
3. The lancet. Psychiatry. Comparative efficacy and tolerability of medications for attention-deficit hyperactivity disorder in children, adolescents, and adults: a systematic review and network meta-analysis.. 2018. PMID 30097390, DOI 10.1016/s2215-0366(18)30269-4. Read the source
4. Autism research : official journal of the International Society for Autism Research. Atomoxetine for attention deficit hyperactivity disorder in children and adolescents with autism: A systematic review and meta-analysis.. 2019. PMID 30653855, DOI 10.1002/aur.2059. Read the source
5. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 7 DRUG INTERACTIONS, Table 8 (Monoamine Oxidase Inhibitors row). 2026. Read the source
6. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 7 DRUG INTERACTIONS, Table 8 (Strong CYP2D6 Inhibitors row). 2026. Read the source
7. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 7 DRUG INTERACTIONS, Table 8 (Albuterol or Other Beta2 Agonists row). 2026. Read the source
8. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 2.2 Administration Instructions. 2026. Read the source
9. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 7 DRUG INTERACTIONS, Table 8 (Antihypertensive Drugs row). 2026. Read the source
10. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 2.8 Recommendations for Discontinuation. 2026. Read the source
11. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 9.3 Dependence. 2026. Read the source
12. Postgraduate medicine. Time-to-onset and -resolution of adverse events before/after atomoxetine discontinuation in adult patients with ADHD.. 2015. PMID 26329980, DOI 10.1080/00325481.2015.1083394. Read the source
13. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 5.2 Severe Liver Injury. 2026. Read the source
14. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 2.6 Switching to or from a Monoamine Oxidase Inhibitor Antidepressant. 2026. Read the source
15. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 5.1 Suicidal Thoughts and Behaviors in Pediatric Patients. 2026. Read the source
16. Drug safety. Hepatic events associated with atomoxetine treatment for attention-deficit hyperactivity disorder.. 2008. PMID 18366245, DOI 10.2165/00002018-200831040-00008. Read the source
17. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 6.1 Clinical Trials Experience (discontinuation due to adverse reactions, pediatric patients 6 years and older). 2026. Read the source
18. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 5.4 Increase in Blood Pressure and Heart Rate. 2026. Read the source
19. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 5.11 Growth (Weight and Height in Short-Term, Placebo-Controlled Studies in Pediatric Patients). 2026. Read the source
20. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 12.5 Pharmacogenomics. 2026. Read the source
21. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 2.1 Recommendations Prior to Initiating STRATTERA Treatment. 2026. Read the source
22. Frontiers in child and adolescent psychiatry. Efficacy and safety of atomoxetine in the treatment of ADHD in children and adolescents: a systematic review.. 2025. PMID 41567279, DOI 10.3389/frcha.2025.1731330. Read the source
23. Journal of child and adolescent psychopharmacology. Meta-analysis of suicide-related behavior or ideation in child, adolescent, and adult patients treated with atomoxetine.. 2014. PMID 25019647, DOI 10.1089/cap.2014.0005. Read the source
24. Pediatrics. Risk of Suicidal Events With Atomoxetine Compared to Stimulant Treatment: A Cohort Study.. 2016. PMID 27244795, DOI 10.1542/peds.2015-3199. Read the source
25. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 9.2 Abuse. 2026. Read the source
26. Pediatrics. Risk of Suicidal Events With Atomoxetine Compared to Stimulant Treatment: A Cohort Study.. 2016. PMID 27244795, DOI 10.1542/peds.2015-3199. Read the source
27. The lancet. Psychiatry. Comparative efficacy and tolerability of medications for attention-deficit hyperactivity disorder in children, adolescents, and adults: a systematic review and network meta-analysis.. 2018. PMID 30097390, DOI 10.1016/s2215-0366(18)30269-4. Read the source
28. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 2.3 Recommended Dosage, Table 1 with footnotes. 2026. Read the source
29. Postgraduate medicine. Time-to-onset and -resolution of adverse events before/after atomoxetine discontinuation in adult patients with ADHD.. 2015. PMID 26329980, DOI 10.1080/00325481.2015.1083394. Read the source
30. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 12.2 Pharmacodynamics. 2026. Read the source
31. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 1 INDICATIONS AND USAGE. 2026. Read the source
32. Postgraduate medicine. Time-to-onset and -resolution of adverse events before/after atomoxetine discontinuation in adult patients with ADHD.. 2015. PMID 26329980, DOI 10.1080/00325481.2015.1083394. Read the source
33. DailyMed (U.S. National Library of Medicine), Structured Product Label. STRATTERA (atomoxetine hydrochloride) capsules - U.S. prescribing information - 8.7 Use in Genomic Subgroups. 2026. Read the source