Guanfacine

Prescription ·Exploratory record · not publication-reviewed ·Updated July 13, 2026

Prescription non-stimulant medication approved in its extended-release form (Intuniv) for ADHD in children and adolescents aged 6–17. A selective alpha-2A adrenergic receptor agonist that strengthens prefrontal cortex function. Particularly effective for hyperactivity, impulsivity, and emotional dysregulation components of ADHD. Also used off-label for tic disorders, anxiety, and PTSD-related hyperarousal. Dosage must be determined by your prescribing physician.

Exploratory record, not a reviewed medical publication.

See the editorial and medical-review policies for the publication gate.

This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.

In short

What the research says.

A quick, data-only summary. The full evidence, dosing, and sources are below.

Prescription non-stimulant medication approved in its extended-release form (Intuniv) for ADHD in children and adolescents aged 6–17. NutriStack rates the supporting evidence as moderate. Common adult dosing is 1–4 mg daily for extended-release; 0.5–2 mg daily for immediate-release (as prescribed by your physician), though a prescriber sets the actual dose. This profile indexes 10 sources.

What it's good for

ADHD symptom improvement⁹
Reduced hyperactivity and impulsivity^1,4
Emotional regulation improvement
No abuse potential
Tic disorder improvement (off-label)^1,4

What to watch for

Somnolence and fatigue
Hypotension
Bradycardia
Known hypersensitivity to guanfacine^1,2
Significant bradycardia or heart block

The bottom line

Evidence rating moderate. Most-documented uses: adhd symptom improvement, reduced hyperactivity and impulsivity, emotional regulation improvement. 10 sources indexed (2023–2025), with 0 interaction records on file.

The science

How it works, mechanistically.

Core mechanism

Selectively stimulates postsynaptic alpha-2A adrenergic receptors in the prefrontal cortex, strengthening prefrontal network connectivity and improving working memory, attention regulation, and behavioral inhibition. Unlike clonidine, guanfacine has 15–25 times greater selectivity for alpha-2A over alpha-2B and alpha-2C receptors, resulting in less sedation and hypotension.

Class

Non-Stimulant ADHD Medication

Dosing

Dosing & protocol.

Common range

1–4 mg daily for extended-release; 0.5–2 mg daily for immediate-release (as prescribed by your physician)

Recommended form

Extended-release tablet (Intuniv) or immediate-release tablet (Tenex)

Do not take extended-release tablets with high-fat meals (increases absorption variability). Do not crush, chew, or break extended-release tablets. Taper gradually when discontinuing to avoid rebound hypertension.

Safety

Full safety detail.

Side effects

Somnolence and fatigue
Hypotension
Bradycardia
Dizziness
Dry mouth
Abdominal pain
Constipation

Contraindications

Known hypersensitivity to guanfacine^1,2
Significant bradycardia or heart block
Concurrent strong CYP3A4 inhibitors or inducers (dose adjustment needed)

Sources

Sources, by evidence tier.

Numbered references. Citations throughout the page link here.

Meta-analyses & systematic reviews

1Guanfacine for the Treatment of Attention-Deficit Hyperactivity Disorder: An Updated Systematic Review and Meta-AnalysisPMIDYu S, Shen S, Tao M · Journal of child and adolescent psychopharmacology · 2023
Yu S, Shen S, Tao M. Guanfacine for the Treatment of Attention-Deficit Hyperactivity Disorder: An Updated Systematic Review and Meta-Analysis. Journal of child and adolescent psychopharmacology. 2023

Randomized controlled trials

2A Randomized Double-Blind Placebo-Controlled Trial of Guanfacine Extended Release for Aggression and Self-Injurious Behavior Associated With Prader-Willi SyndromePMIDSingh D, Silver M, Jacob T · American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics · 2025
Singh D, Silver M, Jacob T. A Randomized Double-Blind Placebo-Controlled Trial of Guanfacine Extended Release for Aggression and Self-Injurious Behavior Associated With Prader-Willi Syndrome. American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics. 2025

Reviews & position papers

3Guanfacine Use in the ICU for Management of Sedation WeaningPMIDLee YR, Garza A, Kiama L · Clinical drug investigation · 2025
Lee YR, Garza A, Kiama L. Guanfacine Use in the ICU for Management of Sedation Weaning. Clinical drug investigation. 2025
4Cardiological Findings in Children and Adolescents Before and After Guanfacine Treatment for Attention Deficit and Hyperactivity DisorderPMIDYükcü B, Önal BS, Çobanoğlu Osmanlı C et al. · Children (Basel, Switzerland) · 2025
Yükcü B, Önal BS, Çobanoğlu Osmanlı C et al.. Cardiological Findings in Children and Adolescents Before and After Guanfacine Treatment for Attention Deficit and Hyperactivity Disorder. Children (Basel, Switzerland). 2025
5Comprehensive analysis of Guanfacine treatment in autism spectrum disorder with comorbid attention deficit hyperactivity disorderPMIDÇobanoğlu Osmanlı C, Baykal S, Önal BS et al. · Scientific reports · 2025
Çobanoğlu Osmanlı C, Baykal S, Önal BS et al.. Comprehensive analysis of Guanfacine treatment in autism spectrum disorder with comorbid attention deficit hyperactivity disorder. Scientific reports. 2025
6Efficacy and safety of guanfacine in hospitalized patients with delirium: A scoping reviewPMIDPattamin N, Phongphithakchai A, Spano S et al. · Critical care and resuscitation : journal of the Australasian Academy of Critical Care Medicine · 2024
Pattamin N, Phongphithakchai A, Spano S et al.. Efficacy and safety of guanfacine in hospitalized patients with delirium: A scoping review. Critical care and resuscitation : journal of the Australasian Academy of Critical Care Medicine. 2024
7Hyperadrenergic Postural Tachycardia Syndrome: Clinical Biomarkers and Response to GuanfacinePMIDOkamoto LE, Urechie V, Rigo S et al. · Hypertension (Dallas, Tex. : 1979) · 2024
Okamoto LE, Urechie V, Rigo S et al.. Hyperadrenergic Postural Tachycardia Syndrome: Clinical Biomarkers and Response to Guanfacine. Hypertension (Dallas, Tex. : 1979). 2024

Reference material

FAQ

Common questions.

Quick answers about Guanfacine, drawn from the data on this page.

What is Guanfacine?

What is Guanfacine used for?

Commonly cited benefits of Guanfacine include: ADHD symptom improvement; Reduced hyperactivity and impulsivity; Emotional regulation improvement; No abuse potential; Tic disorder improvement (off-label). NutriStack rates the overall evidence as moderate.

What is a typical dose of Guanfacine?

A typical adult dose of Guanfacine is 1–4 mg daily for extended-release; 0.5–2 mg daily for immediate-release (as prescribed by your physician). The commonly recommended form is Extended-release tablet (Intuniv) or immediate-release tablet (Tenex). These are general ranges, not personalized advice; confirm the right dose with a clinician.

What are the side effects of Guanfacine?

Reported side effects include somnolence and fatigue, hypotension, bradycardia, dizziness, dry mouth, abdominal pain. This is educational information; check with a healthcare professional before use.

How strong is the evidence for Guanfacine?

NutriStack rates this as Moderate, meaning several aligned RCTs or one large RCT plus supporting reviews. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.

Use this with your stack

Guanfacine in NutriStack.

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