MVIIIHealth The MVIII app
← Back

Research · Medication

Buspirone

Meta-analyses found buspirone and related drugs reduced generalized anxiety symptoms more than placebo, with about 4 to 5 people treated for one extra person improved. Added to an SSRI for depression, it did not beat placebo in two trials. Dizziness occurred in 12% against 3% on placebo, drowsiness matched placebo, and studies found no withdrawal or misuse.

Add to Bio HackChecked 2026-11-13
Status
Prescription drug in the US, FDA-approved for the management of anxiety disorders or the short-term relief of anxiety symptoms, based on trials in generalized anxiety disorder. It is not a controlled substance and its label carries no boxed warning. It is not approved for depression, panic disorder or sexual side effects of antidepressants.
Also called
buspirone hydrochloride, BuSpar, Buspar, azapirone, 5-HT1A partial agonist
Taken for
anxiety, generalized anxiety disorder, adding to an SSRI, sexual side effects of SSRIs, panic attacks, coming off benzodiazepines, indigestion and bloating

Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on

Shown to help2

Reported risks8

What people take it for, and what was found

Shown to help2

StrongVery common

Generalized anxiety

Shown to reduce generalized anxiety symptoms more than placebo, with about 4 to 5 treated for one extra person improved in trials of 4 to 9 weeks.

The numbers and sources
How common
Very common: more than 1 in 10 people.
Effect
In generalized anxiety disorder, azapirones, the drug group that buspirone belongs to, lowered anxiety scores more than placebo (MD -4.91, 95% CI -5.91 to -3.90, 22 studies) and raised response (RR 1.64, 95% CI 1.45 to 1.86, 9 studies) [1]. A Cochrane review found azapirones, including buspirone, superior to placebo, with a number needed to treat of 4.4 (95% CI 2.16 to 15.4) on a global improvement scale [2]. In a network meta-analysis of drugs for generalized anxiety, buspirone beat placebo, in a small sample [3].
Population
2,567 participants in 22 placebo-controlled studies, within a review of 70 studies [1]; 5,908 participants in 36 trials lasting 4 to 9 weeks, one lasting 14 [2]; 25,441 adult outpatients in 89 trials of 22 drugs [3].
Sources
[1], [2], [3], [4]
Caveats
The pooled figures are for azapirones as a group. The label states that benefit beyond 3 to 4 weeks has not been shown in controlled trials [4], and the Cochrane authors called for longer studies [2].
LimitedVery common

Sexual side effects from SSRIs

One trial found 58% of people with SSRI-related sexual problems improved on added buspirone over 4 weeks, against 30% on placebo.

The numbers and sources
How common
Very common: more than 1 in 10 people.
Effect
Among people on citalopram or paroxetine who reported decreased libido or problems with orgasm or ejaculation, about 58% improved in sexual function on added buspirone and 30% on added placebo. The difference was larger in women and appeared in the first week [9].
Population
47 of 117 participants who reported sexual dysfunction at baseline, in a trial of buspirone 20 to 60 mg a day added to an SSRI [9].
Sources
[9]
Caveats
A secondary analysis of 47 people from a trial designed to test something else [9]. Not an approved use.

Mixed results1

Moderate

Compared with benzodiazepines

Mixed results: anxiety scores fell as much as on benzodiazepines, while response was slightly less likely and more people stopped treatment.

The numbers and sources
Effect
Against benzodiazepines in generalized anxiety, azapirones gave the same reduction in symptoms (MD -0.12, 95% CI -0.70 to 0.45, 34 studies) and a slightly lower response rate (RR 0.94, 95% CI 0.90 to 0.99). More people stopped azapirones (RR 1.33, 95% CI 1.16 to 1.53). Azapirones caused less sedation, fatigue, drowsiness, weakness and cognitive complaints than benzodiazepines, at a level resembling placebo, and more headache and nausea [1]. An earlier Cochrane review judged that azapirones may reduce anxiety less than benzodiazepines and found fewer people stopped benzodiazepines [2].
Population
3,160 participants in 34 studies comparing azapirones with benzodiazepines [1]; 36 trials [2].
Sources
[1], [2]
Caveats
Confidence in the comparison with benzodiazepines was rated moderate to low [1]. Short trials.

Not shown to help5

Moderate

Added to an SSRI for depression

Not shown to raise response over placebo when added to an SSRI for depression in two placebo-controlled trials of about 100 people each.

The numbers and sources
Effect
In people who had not responded to citalopram or paroxetine, 50.9% responded after 4 weeks of added buspirone and 46.7% after added placebo, a difference that was not significant [5]. In a second trial in people not responding to fluoxetine or citalopram, depression scores at 6 weeks did not differ between added buspirone and placebo overall. A subgroup with severe symptoms improved more on buspirone [6]. In a large trial without a placebo arm, remission was 30.1% with added buspirone and 29.7% with added bupropion, and more people stopped buspirone for intolerance (20.6% vs 12.5%) [7]. An open-label trial of 89 people found no significant benefit from adding buspirone to escitalopram [8].
Population
119 adults [5]; 102 outpatients [6]; adults whose depression had not remitted on citalopram [7]; 89 adults [8].
Sources
[5], [6], [7], [8]
Caveats
The authors of [5] argued their own trial may have been inconclusive. The severe-symptom result in [6] is a subgroup finding. Not an approved use.
Moderate

Panic disorder

Not shown to help panic disorder: two reviews found no benefit over placebo, and more people dropped out on buspirone.

The numbers and sources
Effect
In three trials of buspirone, dropout for any reason was about twice as frequent as on placebo (RR 2.13, 95% CI 1.11 to 4.07). Effects on general anxiety (MD -2.20, 95% CI -5.45 to 1.06) and agoraphobia were uncertain, and no trial gave usable response data [10]. A later meta-analysis found azapirones did not outperform placebo in panic disorder or social anxiety disorder [1].
Population
170 adults with panic disorder in 3 trials [10]; trials of azapirones across anxiety disorders [1].
Sources
[10], [1]
Caveats
Few small trials, all rated at high risk of attrition bias [10].
Moderate

Anxiety in children and teenagers

Not shown to reduce generalized anxiety symptoms in children and teenagers in two placebo-controlled trials of 559 patients aged 6 to 17.

The numbers and sources
Effect
In two 6-week trials at 15 to 60 mg a day, buspirone and placebo did not differ on symptoms of generalized anxiety disorder [4]. A reanalysis of the two trials found buspirone did not separate from placebo in the fixed-dose trial or the flexible-dose trial, and more children dropped out for adverse events on buspirone [11].
Population
559 pediatric patients aged 6 to 17 with generalized anxiety disorder [4]; the same two trials, with 341 and 227 participants [11].
Sources
[4], [11]
Caveats
The reanalysis judged both trials underpowered to detect small effects [11].
Moderate

Indigestion and gastroparesis symptoms

Not shown to improve functional dyspepsia or gastroparesis symptoms more than placebo. Bloating alone improved in two small trials.

The numbers and sources
Effect
Across three trials, buspirone did not improve functional dyspepsia or gastroparesis symptoms against placebo (SMD -0.14, 95% CI -0.44 to 0.17). Bloating severity improved (SMD -0.41, 95% CI -0.77 to -0.04, 2 studies) [12]. In a 4-week trial in people with gastroparesis symptoms, early fullness scores did not differ from placebo (difference -0.11, 95% CI -0.68 to 0.45) [13].
Population
283 people in 10 studies, 5 of them RCTs [12]; 96 patients, 92% women [13].
Sources
[12], [13]
Caveats
Small trials, most lasting 4 weeks. Not an approved use.
Limited

Easing benzodiazepine withdrawal

One small trial found buspirone did not ease withdrawal in long-term benzodiazepine users, and 7 of 11 on buspirone dropped out.

The numbers and sources
Effect
In people withdrawing from diazepam, buspirone 5 mg three times a day did not relieve withdrawal symptoms, and 7 of 11 on buspirone dropped out against 1 of 12 on placebo [14]. The label states buspirone does not show cross-tolerance with benzodiazepines and will not block their withdrawal syndrome [4].
Population
23 long-term benzodiazepine users [14].
Sources
[14], [4]
Caveats
One trial of 23 people, in which the buspirone group started on higher diazepam doses [14].

Doses studied

The label lists 15 mg a day to start, as 7.5 mg twice daily, raised by 5 mg a day every 2 to 3 days up to 60 mg a day, and notes that trials allowing dose changes commonly used 20 to 30 mg a day in divided doses [4]. The pediatric trials used 15 to 60 mg a day [4].

The trials adding buspirone to an SSRI used 20 to 60 mg a day, with a mean of 48.5 mg at the end in one trial [9], and 10 to 30 mg twice daily in another [6]. The six-month withdrawal comparison used 10 to 40 mg a day [15]. The benzodiazepine withdrawal trial used 5 mg three times a day [14].

Risks

Reported risks7

StrongVery common

Dizziness, nausea and headache

Shown to raise dizziness, in 12% against 3% on placebo across 17 trials, along with nausea, headache and nervousness.

The numbers and sources
How common
Very common: more than 1 in 10 people.
Effect
In pooled data from 17 four-week trials: dizziness 12% vs 3% on placebo, nausea 8% vs 5%, headache 6% vs 3%, nervousness 5% vs 1% and lightheadedness 3% vs under 1%. About 10% of 2,200 patients in premarketing anxiety trials stopped for an adverse event [4]. A meta-analysis of 13 trials found higher odds than placebo of dizziness (OR 4.66, 95% CI 2.07 to 10.47), constipation (OR 4.11, 95% CI 1.34 to 12.55) and gastric distress (OR 1.97, 95% CI 1.03 to 3.78) [16]. A second found more nausea and dizziness than placebo [1].
Population
477 patients on buspirone and 464 on placebo in 17 trials [4]; 13 randomized trials reporting side effects [16]; 70 studies of azapirones [1].
Sources
[4], [16], [1]
Caveats
The label trials lasted 4 weeks.
LimitedUncommon

Sexual side effects

The label lists decreased or increased libido in between 1 in 100 and 1 in 1,000 people, and delayed ejaculation and impotence in fewer than 1 in 1,000.

The numbers and sources
How common
Uncommon: between 1 in 1,000 and 1 in 100 people.
Effect
In premarketing studies, decreased or increased libido was classed as infrequent, meaning 1 in 100 to 1 in 1,000 patients, and delayed ejaculation and impotence as rare, meaning fewer than 1 in 1,000. No placebo rates are given [4].
Population
About 3,000 subjects who took multiple doses in premarketing studies [4].
Sources
[4]
Caveats
Uncontrolled counts, so the share caused by the drug is unknown.
LimitedUncommon

Weight change

The label lists both weight gain and weight loss in between 1 in 100 and 1 in 1,000 people in premarketing studies.

The numbers and sources
How common
Uncommon: between 1 in 1,000 and 1 in 100 people.
Effect
Weight gain and weight loss were each classed as infrequent, meaning 1 in 100 to 1 in 1,000 patients. No placebo rates are given [4].
Population
About 3,000 subjects who took multiple doses in premarketing studies [4].
Sources
[4]
Caveats
Uncontrolled counts with no measured change in weight.
LimitedHow often is not known

Use with MAOIs

The label lists MAOIs as a contraindication, within 14 days in either direction, citing reports of raised blood pressure and a risk of serotonin syndrome.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
The label states there have been reports of elevated blood pressure when buspirone was added to a regimen including a monoamine oxidase inhibitor, and lists the combination as contraindicated because of an increased risk of serotonin syndrome, elevated blood pressure or both. It applies the same to the antibiotic linezolid and intravenous methylene blue [4].
Population
Reports summarized in labeling [4].
Sources
[4]
Caveats
No rate is given.
LimitedHow often is not known

Serotonin syndrome

The label reports serotonin syndrome with buspirone, mostly when taken with other serotonergic drugs such as SSRIs, SNRIs or triptans. It gives no rate.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
The label states that potentially life-threatening serotonin syndrome has been reported with serotonergic drugs including buspirone, alone but particularly with other serotonergic drugs including triptans, with MAOIs, or with antipsychotics and other dopamine antagonists. Serotonin syndrome also appears among voluntary reports since marketing [4].
Population
Postmarketing reports summarized in labeling [4].
Sources
[4]
Caveats
Voluntary reports with no denominator.
LimitedHow often is not known

Raised buspirone levels with other medicines and grapefruit juice

The label reports buspirone blood levels rising 3 to 50 times with certain antibiotics, antifungals, heart drugs, nefazodone and large amounts of grapefruit juice.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
In studies in healthy volunteers, total exposure to buspirone rose 6-fold with the antibiotic erythromycin, 19-fold with itraconazole, 5.5-fold with diltiazem, 3.4-fold with verapamil, up to 50-fold with the antidepressant nefazodone and 9.2-fold with double-strength grapefruit juice. The erythromycin and itraconazole studies also recorded more buspirone side effects. The antibiotic rifampin lowered exposure by 89.6%. Buspirone raised blood levels of haloperidol in one study [4].
Population
Healthy volunteers in drug interaction studies, 9 in the diltiazem and verapamil study [4].
Sources
[4]
Caveats
Small single-dose studies of drug levels, not rates of harm.
LimitedHow often is not known

Restlessness and movement symptoms

The label reports a syndrome of restlessness soon after starting in a small fraction of patients, and rare voluntary reports of movement disorders.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
The label states that controlled trials did not identify significant antipsychotic-like activity, and that a syndrome of restlessness appearing shortly after the start of treatment has been reported in a small fraction of patients. Voluntary reports since marketing include rare cases of dystonia, parkinsonism, akathisia, dyskinesia and restless leg syndrome [4].
Population
Controlled trials and postmarketing reports summarized in labeling [4].
Sources
[4]
Caveats
No rate is given, and the label says cause has not been established for the voluntary reports.

Mixed results1

LimitedHow often is not known

Raised liver enzymes with trazodone

Mixed results: one report linked buspirone taken with trazodone to liver enzyme rises of 3 to 6 times in a few patients, and a repeat study did not.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
The label describes one report suggesting that taking trazodone and buspirone together may have caused 3-fold to 6-fold elevations in the liver enzyme ALT in a few patients. A similar study attempting to replicate the finding identified no effect on liver enzymes [4].
Population
A few patients in one report, and a follow-up study, both summarized in labeling [4].
Sources
[4]
Caveats
One unreplicated report. The label gives no numbers.

Checked, no increase found4

Moderate

Drowsiness and sedation

Not shown to cause more drowsiness than placebo: 10% against 9% across 17 trials, and less sedation than benzodiazepines.

The numbers and sources
How common
Common: between 1 in 100 and 1 in 10 people.
Effect
Drowsiness was reported by 10% on buspirone and 9% on placebo [4]. In trials against benzodiazepines, azapirones caused less sedation, fatigue, drowsiness and cognitive complaints, at a level resembling placebo [1]. The label states that buspirone did not prolong or intensify the sedative effects of triazolam or flurazepam when given together [4].
Population
477 patients on buspirone and 464 on placebo [4]; trials comparing azapirones with benzodiazepines [1].
Sources
[4], [1]
Caveats
The label adds that effects on any one person may not be predictable.
Moderate

Sleep effects

Not shown to raise insomnia: 3% against 3% on placebo across 17 trials. Dream disturbances were reported in at least 1 in 100.

The numbers and sources
How common
Common: between 1 in 100 and 1 in 10 people.
Effect
Insomnia was reported by 3% on buspirone and 3% on placebo. In the wider premarketing program, dream disturbances were classed as frequent, meaning at least 1 in 100 patients, with no placebo rate given [4].
Population
477 patients on buspirone and 464 on placebo, and about 3,000 subjects in premarketing studies [4].
Sources
[4]
Caveats
Four-week trials relying on reported events.
Moderate

Dependence, misuse and withdrawal

Not shown to cause withdrawal or misuse: after six months, abrupt stopping produced no withdrawal reaction, unlike a benzodiazepine in the same trial.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
After six months of treatment, blind and abrupt stopping brought a significant rise in symptoms consistent with withdrawal in the group on the benzodiazepine clorazepate and not in the group on buspirone [15]. The label states that human and animal studies showed no potential for abuse or diversion and no evidence of tolerance or dependence, and that volunteers with a history of recreational drug or alcohol use could not tell buspirone from placebo in two studies [4].
Population
Anxious outpatients treated for six months with buspirone 10 to 40 mg a day or clorazepate [15]; volunteers in two double-blind studies [4].
Sources
[15], [4]
Caveats
The buspirone group had a higher dropout rate over the six months [15]. The label notes that experiments cannot fully predict misuse once a drug is marketed.
Limited

Alcohol

Not shown to add to impairment from alcohol in the formal interaction studies described in the label.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
The label states that formal studies of buspirone with alcohol indicate it does not increase alcohol-induced impairment in motor and mental performance [4].
Population
Volunteers in interaction studies summarized in labeling, with no head count given [4].
Sources
[4]
Caveats
The label gives no study details.

Possible, not studied in people1

Untested

Pregnancy

Not studied in people. Animal studies found no fertility impairment or fetal damage at about 30 times the maximum human dose.

No study in people. This rests on animal studies.

The numbers and sources
Effect
The label states that reproduction studies in rats and rabbits at about 30 times the maximum labeled human dose showed no fertility impairment or fetal damage, and that adequate and well-controlled studies in pregnant women have not been performed [4].
Population
Rats and rabbits [4].
Sources
[4]
Caveats
Animal reproduction studies do not always predict what happens in people, as the label itself notes.

Claims tested and not found

  1. That buspirone treats panic disorder. A Cochrane review of three trials could not show benefit and found more dropouts than on placebo [10], and a later meta-analysis found azapirones did not outperform placebo in panic disorder [1].
  2. That adding buspirone to an SSRI lifts depression that has not responded. Response did not differ from added placebo in two trials [5][6].
  3. That buspirone eases coming off a benzodiazepine. In a placebo-controlled trial of 23 long-term users, it did not relieve withdrawal symptoms [14].
  4. That buspirone relieves anxiety in children and teenagers. Two placebo-controlled trials in 559 patients aged 6 to 17 found no difference from placebo [4][11].
  5. That buspirone relieves indigestion or gastroparesis symptoms. Pooled trials and a 96-patient trial found no difference from placebo on overall symptoms [12][13].

Sources

  1. Rossano F, Caiazza C, Zotti N, et al. The efficacy, safety, and adverse events of azapirones in anxiety disorders: A systematic review and meta-analysis of randomized controlled trials. European Neuropsychopharmacology. 2023. https://doi.org/10.1016/j.euroneuro.2023.07.008
  2. Chessick CA, Allen MH, Thase ME, et al. Azapirones for generalized anxiety disorder. Cochrane Database of Systematic Reviews. 2006. https://doi.org/10.1002/14651858.CD006115
  3. Slee A, Nazareth I, Bondaronek P, et al. Pharmacological treatments for generalised anxiety disorder: a systematic review and network meta-analysis. The Lancet. 2019. https://doi.org/10.1016/S0140-6736(18)31793-8
  4. U.S. Food and Drug Administration. Buspirone hydrochloride tablets, prescribing information (Accord Healthcare). 2026. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3da22999-f5fb-49fd-acde-c3006598e985
  5. Landén M, Björling G, Ågren H, et al. A Randomized, Double-Blind, Placebo-Controlled Trial of Buspirone in Combination With an SSRI in Patients With Treatment-Refractory Depression. The Journal of Clinical Psychiatry. 1998. https://doi.org/10.4088/jcp.v59n1204
  6. Appelberg BG, Syvälahti EK, Koskinen TE, et al. Patients With Severe Depression May Benefit From Buspirone Augmentation of Selective Serotonin Reuptake Inhibitors: results from a placebo-controlled, randomized, double-blind, placebo wash-in study. The Journal of Clinical Psychiatry. 2001. https://doi.org/10.4088/jcp.v62n0608
  7. Trivedi MH, Fava M, Wisniewski SR, et al. Medication Augmentation after the Failure of SSRIs for Depression. New England Journal of Medicine. 2006. https://doi.org/10.1056/NEJMoa052964
  8. Shin C, Ko YH, Shim SH, et al. Efficacy of Buspirone Augmentation of Escitalopram in Patients with Major Depressive Disorder with and without Atypical Features: A Randomized, 8 Week, Multicenter, Open-Label Clinical Trial. Psychiatry Investigation. 2020. https://doi.org/10.30773/pi.2020.0017
  9. Landén M, Eriksson E, Ågren H, et al. Effect of Buspirone on Sexual Dysfunction in Depressed Patients Treated With Selective Serotonin Reuptake Inhibitors. Journal of Clinical Psychopharmacology. 1999. https://doi.org/10.1097/00004714-199906000-00012
  10. Imai H, Tajika A, Chen P, et al. Azapirones versus placebo for panic disorder in adults. Cochrane Database of Systematic Reviews. 2014. https://doi.org/10.1002/14651858.CD010828.pub2
  11. Strawn JR, Mills JA, Cornwall GJ, et al. Buspirone in Children and Adolescents with Anxiety: A Review and Bayesian Analysis of Abandoned Randomized Controlled Trials. Journal of Child and Adolescent Psychopharmacology. 2018. https://doi.org/10.1089/cap.2017.0060
  12. Mohamedali Z, Amarasinghe G, Hopkins CWP, et al. Effect of Buspirone on Upper Gastrointestinal Disorders of Gut-Brain Interaction: A Systematic Review and Meta-analysis. Journal of Neurogastroenterology and Motility. 2025. https://doi.org/10.5056/jnm24115
  13. Parkman HP, Yates KP, Sarosiek I, et al. Buspirone for early satiety and symptoms of gastroparesis: A multi-centre, randomised, placebo-controlled, double-masked trial (BESST). Alimentary Pharmacology & Therapeutics. 2023. https://doi.org/10.1111/apt.17479
  14. Ashton CH, Rawlins MD, Tyrer SP. A Double-Blind Placebo-Controlled Study of Buspirone in Diazepam Withdrawal in Chronic Benzodiazepine Users. British Journal of Psychiatry. 1990. https://doi.org/10.1192/bjp.157.2.232
  15. Rickels K, Schweizer E, Csanalosi I, et al. Long-term Treatment of Anxiety and Risk of Withdrawal: Prospective Comparison of Clorazepate and Buspirone. Archives of General Psychiatry. 1988. https://doi.org/10.1001/archpsyc.1988.01800290060008
  16. Du Y, Li Q, Dou Y, et al. Side effects and cognitive benefits of buspirone: A systematic review and meta-analysis. Heliyon. 2024. https://doi.org/10.1016/j.heliyon.2024.e28918

Everything in the library