Guanfacine for Alcohol Use Disorder (AUD)

Inclusion Criteria:

* be assigned as a biological male or female at birth and identify as such
* meet current Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM V) criteria for moderate to severe AUD
* be ≥18 years old and have a body mass index (BMI) of 18-35
* express a desire to quit alcohol as determined by the Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES)
* demonstrate a positive urine for alcohol on admission to study procedures
* be able to provide informed verbal and written consent
* be able to read English and complete study evaluations
* be in good health as verified by the intake 1 physical examination

Exclusion Criteria:

* meet criteria for moderate to severe Substance Use Disorder (SUD), excluding alcohol and nicotine
* have a positive screen for substances of abuse, excluding alcohol, nicotine,
* being psychotic or otherwise severely psychiatrically disabled (including suicidal, homicidal, current mania)
* meet criteria for physiological dependence on alcohol requiring medical detoxification
* regular use of medications in the last 6 months that, in the opinion of the site physician may be contraindicated with GXR and be potentially harmful to the participant
* be pregnant or breast feeding
* be using monophasic contraceptives
* have cardiovascular disease including high blood pressure,
* be hypotensive with sitting blood pressure below 100/50 mmHG
* have bradycardia with a sitting heart rate (HR) of \<60 bpm
* show EKG evidence of any clinically significant conduction abnormalities, including a Bazett's corrected QT interval (QTc) \>470 msec for women and QTc\>450 msec for men.