Clinical Trials

Numerous clinical trials evaluate the therapeutic efficacy and safety of immediate- and extended-release Guanfacine Hydrochloride for conditions including Attention Deficit Hyperactivity Disorder (ADHD), smoking cessation, postural orthostatic tachycardia syndrome (POTS), dysautonomia, and alcohol or cocaine dependency. Spanning Early Phase 1 through Phase 4, these completed, active, and upcoming studies demonstrate the drug's broad therapeutic potential across diverse medical indications. Research is supported by both pharmaceutical companies, such as Shire and Takeda, and major academic medical centers, including Yale University, Johns Hopkins University, and the Icahn School of Medicine at Mount Sinai.

NCT Number Recruitment Conditions Sponsor/Collaborators Start Date Phases
NCT07300956 NOT_YET_RECRUITING
Attention-Deficit/Hyperactivity Disorder (ADHD)
Children's Hospital Medical Center, Cincinnati
 2026-02 PHASE4
NCT06629259 RECRUITING
Alcohol Use Disorder
Indiana University
 2025-10-03 PHASE2
NCT06408246 RECRUITING
Depression
Stanford University
 2026-03-03 PHASE2
NCT07757555 NOT_YET_RECRUITING
Postural Orthostatic Tachycardia Syndrome (POTS); Dysautonomia; Orthostatic Intolerance; Autonomic Nervous System Diseases
Johns Hopkins University
 2026-08-15 EARLY_PHASE1
NCT03764098 RECRUITING
Alcohol Use
Yale University
 2020-08-10 PHASE2
NCT06642181 RECRUITING
Mindfulness; Guanfacine; Opioid Use Disorder
Rutgers, The State University of New Jersey
 2025-07-15 PHASE1
NCT05957848 RECRUITING
Cannabis Use Disorder
Orygen
 2023-07-27 PHASE2
NCT04085172 COMPLETED
Attention Deficit Hyperactivity Disorder
Shire
 2019-09-18 PHASE4
NCT06042257 TERMINATED
Hyperactivity in Children With Down Syndrome; Impulsivity in Children With Down Syndrome
Rachel G. Greenberg, MD, MB, MHS
 2024-12-09 PHASE2
NCT04198116 COMPLETED
Smoking Cessation
Yale University
 2020-11-01 PHASE2
NCT03333668 COMPLETED
ADHD
King's College London
 2018-10-01
NCT03116126 UNKNOWN
Alzheimer Disease
Imperial College London
 2019-01-04 PHASE3
NCT04742673 COMPLETED
Critical Illness; Delirium; Cognitive Impairment
Vanderbilt University Medical Center
 2021-05-04 PHASE2
NCT04181736 COMPLETED
Major Depressive Disorder
Stanford University
 2022-09-14 PHASE4
NCT05657860 COMPLETED
Prader-Willi Syndrome; Aggression; Self-Injurious Behavior; Pathologic Processes; Behavioral Symptoms; Intellectual Disability; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Abnormalities, Multiple; Congenital Abnormalities; Chromosome Disorders; Genetic Diseases, Inborn; Obesity; Overnutrition; Nutrition Disorders; Antihypertensive Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Physiological Effects of Drugs; Skin-Picking
Maimonides Medical Center
 2020-12-17 PHASE4
NCT03865940 COMPLETED
Trigeminal Neuralgia
Vanderbilt University Medical Center
 2019-11-04 PHASE2
NCT05273567 COMPLETED
Cannabis Use
New York State Psychiatric Institute
 2022-06-01 PHASE2
NCT04578886 COMPLETED
Delirium
University of Alabama at Birmingham
 2020-11-23 PHASE3
NCT01681264 TERMINATED
Chronic Pain
Massachusetts General Hospital
 2014-09 PHASE4
NCT03980184 COMPLETED
Substance Use Disorders
Yale University
 2019-11-01 PHASE2
NCT02192398 TERMINATED
Chronic Pain
Massachusetts General Hospital
 2014-09
NCT02259517 TERMINATED
Attention Deficit Hyperactivity Disorder
New York State Psychiatric Institute
 2014-09
NCT00773357 COMPLETED
Smoking
Yale University
 2008-10 PHASE2
NCT03137082 COMPLETED
Alcohol Abstinence
Stony Brook University
 2017-07-12 PHASE1; PHASE2
NCT02051309 COMPLETED
Smoking Cessation
Yale University
 2014-03 PHASE2
NCT04066088 WITHDRAWN
Prader-Willi Syndrome
NYU Langone Health
 2019-12-01 PHASE4
NCT02164422 COMPLETED
Alcohol Drinking
Yale University
 2014-06 PHASE2
NCT03258476 WITHDRAWN
Stress Disorder
UConn Health
 2019-03-01 PHASE4
NCT04866030 Completed
Attention Deficit Hyperactivity Disorder (ADHD)
Shire|Takeda
 2019-03-11 --
NCT02788851 UNKNOWN
Attention Deficit Hyperactivity Disorder (ADHD)
McGill University Health Centre/Research Institute of the McGill University Health Centre
 2016-04
NCT05870605 Completed
Attention Deficit Hyperactivity Disorder (ADHD)
Shire|Takeda
 2018-11-15 --
NCT02882854 COMPLETED
Postoperative Nausea and Vomiting; Pain, Postoperative
Vanderbilt University Medical Center
 2016-11
NCT02524899 COMPLETED
Schizotypal Personality Disorder; SPD
Icahn School of Medicine at Mount Sinai
 2014-01 PHASE2
NCT00223717 COMPLETED
Hypertension
Vanderbilt University
 2001-01 PHASE1
NCT01904526 COMPLETED
Smoking
Yale University
 2013-07 PHASE2
NCT01547000 COMPLETED
Tourette Disorder; Tourette Syndrome
Yale University
 2012-04 PHASE4
NCT00585754 COMPLETED
Cocaine Dependent; Alcohol Dependent
Yale University
 2006-04 PHASE1
NCT02699125 COMPLETED
Obstructive Sleep Apnea
University of California, San Diego
 2015-01 PHASE4
NCT01467999 COMPLETED
Cannabis Dependence
New York State Psychiatric Institute
 2012-02 PHASE1
NCT01500694 COMPLETED
Attention Deficit Hyperactivity Disorder (ADHD)
Shire
 2012-03-20 PHASE3
NCT01133847 COMPLETED
Attention Deficit Hyperactivity Disorder; Reading Disabilities
The University of Texas Health Science Center, Houston
 2010-11 PHASE4
NCT01985581 COMPLETED
Attention Deficit Hyperactivity Disorder
JPM van Stralen Medicine Professional
 2013-10 PHASE4
NCT01600885 COMPLETED
NMDA Receptor Function
Yale University
 2008-08
NCT02141113 COMPLETED
Adult Attention-Deficit Hyperactivity Disorder
Rochester Center for Behavioral Medicine
 2012-11 PHASE4
NCT00955253 COMPLETED
Stroke; Hemispatial Neglect
Imperial College London
 2010-04 PHASE2
NCT01238575 COMPLETED
Pervasive Development Disorders
Yale University
 2011-12 PHASE4
NCT01709695 COMPLETED
ADHD; Attention Deficit Hyperactivity Disorder
Icahn School of Medicine at Mount Sinai
 2011-03 PHASE4
NCT01177306 COMPLETED
Attention Deficit Hyperactivity Disorder
Lori A. Schweickert, MD
 2010-07 PHASE4
NCT03662763 COMPLETED
Attention Deficit Disorder
Maastricht University Medical Center
 2011-09 PHASE3
NCT01470469 COMPLETED
Generalized Anxiety Disorder (GAD); Anxiety, Separation; Phobia, Social
Shire
 2012-01-04 PHASE2
NCT01904526 Completed
Smoking
Yale University|National Institute on Drug Abuse (NIDA)
 2013-07 Phase 2
NCT01081145 COMPLETED
Attention-deficit/Hyperactivity Disorder
Shire
 2010-05-11 PHASE3
NCT01081132 COMPLETED
Attention-Deficit/Hyperactivity Disorder
Shire
 2011-09-19 PHASE3
NCT01244490 COMPLETED
Attention Deficit Hyperactivity Disorder
Shire
 2011-01-17 PHASE3
NCT01146002 COMPLETED
Attention-deficit/Hyperactivity Disorder
Neurology Group of Bergen County, P.A.
 2010-06 PHASE4
NCT00935493 COMPLETED
Cognitive Aging
Yale University
 2009-06
NCT00613015 COMPLETED
Cocaine Related Disorders
Medical University of South Carolina
 2008-05 PHASE2
NCT01156051 TERMINATED
Attention-Deficit/Hyperactivity Disorder; Attention Deficit Disorder; Insomnia; Sleep Disorders
Children's Specialized Hospital
 2010-06 PHASE4
NCT01069523 COMPLETED
Attention Deficit Disorder With Hyperactivity
The University of Texas Health Science Center at San Antonio
 2010-03 PHASE4
NCT00429273 COMPLETED
Attention Deficit Disorder With Hyperactivity
University of California, Los Angeles
 2007-01 PHASE4
NCT00997984 COMPLETED
Attention-Deficit/Hyperactivity Disorder
Shire
 2009-11-17 PHASE3
NCT00389675 TERMINATED
Hypertension
Gilead Sciences
 2007-05 PHASE3
NCT00389779 COMPLETED
Hypertension
Gilead Sciences
 2006-09 PHASE3
NCT00672984 COMPLETED
Healthy Volunteers
Shire
 2008-04-18 PHASE1
NCT00469664 UNKNOWN
Schizophrenia; Schizoaffective Disorder; Cognitive Impairment
Research Foundation for Mental Hygiene, Inc.
 2000-02 PHASE4
NCT00367835 COMPLETED
ADHD
Shire
 2006-12-04 PHASE3
NCT00150592 COMPLETED
Attention Deficit Disorder With Hyperactivity
Shire
 2005-05-12 PHASE2
NCT00151996 COMPLETED
Attention Deficit Disorder With Hyperactivity
Shire
 2004-08-16 PHASE2
NCT00025779 COMPLETED
Attention Deficit Disorder With Hyperactivity; Autistic Disorder; Pervasive Development Disorders
National Institute of Mental Health (NIMH)
 2001-10
NCT00152009 COMPLETED
Attention Deficit Disorder With Hyperactivity
Shire
 2003-01-29 PHASE3
NCT00353379 TERMINATED
Schizotypal Personality Disorder; Personality Disorders
Icahn School of Medicine at Mount Sinai
 1995-09 PHASE4
NCT00004376 COMPLETED
Tourette Syndrome
National Center for Research Resources (NCRR)
 1994-09 PHASE3
NCT00358969 UNKNOWN
Borderline Personality Disorder
Icahn School of Medicine at Mount Sinai
 2006-07
NCT00018603 COMPLETED
Post-Traumatic Stress Disorder
US Department of Veterans Affairs
 1999-11 PHASE1

(data from https://clinicaltrials.gov, updated on 2026-01-07)

Check the Guanfacine Hydrochloride product page for in-depth specifications, including solubility, stock solutions, MOA, and working concentrations.

Compliance for Clinical Use

Mechanism and Biochemical Profile

Guanfacine Hydrochloride functions as a selective agonist of presynaptic α2A-adrenoceptors, which inhibits adenylate cyclase activity and decreases intracellular cAMP synthesis to suppress central sympathetic outflow. This reduction in noradrenergic signaling enhances prefrontal cortical network connectivity and lowers peripheral vascular resistance, providing the physiological basis for its therapeutic efficacy in clinical trials for Attention Deficit Hyperactivity Disorder and autonomic conditions.

Appendix RUO and cGMP Quality Standards

Quality Dimension RUO (Research Use Only) cGMP (Current Good Manufacturing Practice)
Clinical Applicability Prohibited in human clinical trials or medical diagnostics. Mandatory for human clinical trials (Phase I–III) and therapies.
Regulatory Status Non-regulated grade; exempt from drug manufacturing laws. Legally enforced by health authorities (e.g., FDA, EMA, NMPA).
Facility Environment Unclassified analytical or research laboratories. Validated Cleanrooms (ISO Class 5–8) with continuous monitoring.
Quality Control Basic purity and activity testing. Rigorous safety release testing (Sterility, Endotoxin, Mycoplasma).
Process Validation Basic equipment calibration; no process validation required. Full qualification (IQ/OQ/PQ) and complete batch records.
Quality Assurance Vendor self-declared without required formal QMS. Mandatory QA/QC unit, Change Control, CAPA, and vendor audits.
Regulatory Impact High risk of IND rejection if used as a critical raw material. Required for IND/NDA filings, supported by Drug Master Files (DMF).

Footnotes

Regulatory Note: Governed by FDA (21 CFR Parts 210/211/312), EMA (EudraLex Vol 4), ICH Guidelines (E6/Q7/Q9/Q10), and compendial standards (USP <71>/<85>/<1043>).

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Note: Technical data last updated: Sep 1, 2026.