Guanfacine: Uses, Side Effects, Dosage

Published on: 28 Jun 2023
Clinically Reviewed by Bisma Anwar, LMHC

Guanfacine is a generic medication that belongs to the class of drugs known as alpha-2A agonists. It acts on specific receptors in the brain, potentially leading to lower blood pressure and improved focus and concentration. 

Guanfacine medication treats various medical and mental health conditions, including hypertension and cardiovascular disease, attention-deficit hyperactivity disorder (ADHD), and oppositional defiant disorder (ODD) that occurs comorbidly with ADHD. Studies done in 2017 and 2013 also suggest Guanfacine can be helpful in treating anxiety in children, too — although it hasn’t been FDA-approved for this use. 

If you’ve wondered what Guanfacine is used for, or the side effects of this drug, keep reading — we’re covering everything you need to know here. 

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What is Guanfacine?

Guanfacine is a drug that treats ADHD and hypertension. It affects the brain chemicals involved in impulse control, concentration, and hyperactivity. As a result, when used for ADHD, Guanfacine helps reduce impulsivity, improve focus, increase self-control, and reduce hyperactivity symptoms associated with ADHD.

“Guanfacine is a non-stimulant medication often used to address inattention when stimulants are not warranted. It may be considered more benign for children and non-addictive, while it has been prescribed short-term at times. Always work with your physician to stay attentive to potential negative side effects and to understand optimal effectiveness for you or your loved one.”

Talkspace therapist Elizabeth Keohan, LCSW-C, LICSW, LCSW

How does Guanfacine work?

Guanfacine is a member of the alpha-2A agonist class of drugs, which stimulate particular brain receptors that control neurotransmitter release. By stimulating these receptors, Guanfacine increases the release of norepinephrine in the prefrontal cortex, which is associated with promoting low blood pressure, improved cognitive abilities, and reduced impulsivity.

How does Guanfacine make you feel?

Guanfacine can help you feel calm and able to focus, but it can also cause sleepiness and dizziness, among other various side effects.

Guanfacine Uses

What is Guanfacine used for? The extended-release formula of Guanfacine has been FDA-approved to treat ADHD symptoms in children 6 years and older, either alone or with other medications like stimulants or antidepressants. 

While Guanfacine for anxiety has been studied and does appear to be potentially effective, more research is needed before we know its true efficacy. 

Guanfacine for ADHD and oppositional behavior

Because Guanfacine acts on the alpha-2A adrenergic receptor in the brain, it decreases activity within certain regions associated with overstimulation or excitation. Thus, it can effectively treat ADHD and oppositional defiant disorder, according to research

Off-label uses

Guanfacine can also be used off-label — which means it wasn’t intended for but is effective in treating — to treat several other conditions besides ADHD. It’s sometimes used to treat: 

Pros & Cons of Guanfacine

Pros of GuanfacineCons of Guanfacine
Bolsters attentiveness & focusSide effects can include fatigue & dizziness
Reduces impulsive behaviorIn rare cases, can cause low white blood cell count or liver damage
Controls high blood pressurePotential for increased anxiety
Can prevent stroke & heart attackCan interact negatively with other drugs

Side Effects of Guanfacine

While Guanfacine medication can be an effective treatment for several conditions, like most drugs, there are some side effects associated with use. 

Common side effects of Guanfacine may include dizziness, fatigue, nausea, dry mouth, and headache.

  • Drowsiness: Guanfacine can cause drowsiness in some people, especially at higher doses. It’s important to use great caution to prevent severe drowsiness while driving or operating machinery while taking this medication.
  • Headache: Headaches are a commonly reported side effect of Guanfacine use. If headaches persist, consult your doctor to determine if an alternate course of treatment is a better option.
  • Nausea: Some people may feel queasy or vomit after taking Guanfacine, particularly if they take too much or rapidly up their dosage. Taking smaller doses more frequently throughout the day may help reduce these symptoms.
  • Dry mouth: Dry mouth is another possible side effect of Guanfacine use. Staying hydrated can help alleviate the discomfort of dry mouth associated with Guanfacine use.
  • Possible weight gain: Guanfacine is linked to appetite stimulation and, as a result, may lead to weight gain. Learn more about weight gain from Guanfacine.

If side effects don’t go away over time, it’s recommended that you talk to a doctor before stopping any medication. If you quit the medication suddenly, you may experience Guanfacine withdrawal symptoms.

Guanfacine Dosage

Guanfacine is available as both immediate and extended-release tablets, with different recommended dosages for each. 

Guanfacine dosage should only be determined by a medical professional based on individual needs and responses to treatment. 

How to take Guanfacine

Take Guanfacine exactly as directed. Do not break, chew, or crush the tablet. Instead, take it whole with a glass of water or milk. 

Be sure to inform a doctor of any significant weight changes in a child who’s taking Guanfacine so the dosage can be appropriately adjusted if needed. 

Additional Considerations

Before beginning Guanfacine, it’s important to consider any potential interactions with other drugs and warnings.  

“All medications have the possibility of side effects and some contraindications. Educating yourself when implementing something new into your or your child’s routine is super important. At the same time, staying attentive to life changes, routines, and stressors is necessary. Though not a stimulant, extended-release medications should still be managed and never abruptly stopped. Tap your physician when things change to maintain an effective treatment plan for optimal health.”

Talkspace therapist Elizabeth Keohan, LCSW-C, LICSW, LCSW


Guanfacine can interact with certain medications, including antidepressants and antipsychotics. Before starting it, inform your doctor of any other drugs you currently use — prescription and over-the-counter — to avoid a potential drug interaction and prevent undesired reactions.


People who’ve had an allergic reaction to clonidine or any of its components should also avoid using Guanfacine. Anyone with kidney problems or heart disease should seek medical advice before taking Guanfacine, as it may be hazardous to their health. Women expecting or nursing a baby should consult their doctor on specific drug information before taking Guanfacine — it could cause harm to the baby.

Look for signs of depression, suicidal ideation, agitation, irritability, aggression, panic attacks, or hallucinations while taking Guanfacine. These could indicate deeper underlying mental health conditions that may need prompt medical attention. 

Guanfacine Alternatives

For some people, an alternative ADHD medication aside from Guanfacine might better treat oppositional symptoms.  


One option is stimulant medications such as methylphenidate or dextroamphetamine. These drugs work by increasing the amount of dopamine and norepinephrine in the brain, helping to improve focus and reduce impulsivity. Although usually well-tolerated, they can cause unwanted effects like sleeplessness, decreased appetite, accelerated or slow heart rate, and uneasiness. 


Another option is Strattera (atomoxetine), an antidepressant drug that works differently than stimulants to help with ADHD symptoms. It boosts norepinephrine levels in the brain but not dopamine, thus avoiding potential issues caused by an overstimulation of dopamine pathways, such as addiction or elation. However, atomoxetine can still cause adverse effects, including nausea, migraine, lightheadedness, weariness, and irritability.  

Online Guanfacine Prescription With Talkspace Psychiatry

Talkspace is an online platform that provides people with access to various mental health treatments, including online Guanfacine medication prescriptions.  

After consulting with an online psychiatrist, you can receive a prescription to treat ADHD or other mental health conditions if included in your treatment plan. Learn more at Talkspace today. 


  1. Strawn JR, Compton SN, Robertson B, Albano AM, Hamdani M, Rynn MA. Extended release guanfacine in pediatric anxiety disorders: A pilot, randomized, placebo-controlled trial. Journal of Child and Adolescent Psychopharmacology. 2017;27(1):29-37. doi:10.1089/cap.2016.0132. Accessed March 27, 2023.
  2. Connor DF, Grasso DJ, Slivinsky MD, Pearson GS, Banga A. An open-label study of Guanfacine extended release for traumatic stress related symptoms in children and adolescents. Journal of Child and Adolescent Psychopharmacology. 2013;23(4):244-251. doi:10.1089/cap.2012.0119. Accessed March 27, 2023.
  3. Srour H, Pandya K, Flannery A, Hatton K. Enteral guanfacine to treat severe anxiety and agitation complicating critical care after cardiac surgery. Seminars in Cardiothoracic and Vascular Anesthesia. 2018;22(4):403-406. doi:10.1177/1089253218768537. Accessed March 27, 2023.
  4. Pringsheim T, Hirsch L, Gardner D, Gorman DA. The pharmacological management of oppositional behaviour, conduct problems, and aggression in children and adolescents with attention-deficit hyperactivity disorder, oppositional defiant disorder, and conduct disorder: A systematic review and meta-analysis. part 1: Psychostimulants, alpha-2 agonists, and Atomoxetine. The Canadian Journal of Psychiatry. 2015;60(2):42-51. doi:10.1177/070674371506000202. Accessed March 27, 2023.

Talkspace articles are written by experienced mental health-wellness contributors; they are grounded in scientific research and evidence-based practices. Articles are extensively reviewed by our team of clinical experts (therapists and psychiatrists of various specialties) to ensure content is accurate and on par with current industry standards.

Our goal at Talkspace is to provide the most up-to-date, valuable, and objective information on mental health-related topics in order to help readers make informed decisions.

Articles contain trusted third-party sources that are either directly linked to in the text or listed at the bottom to take readers directly to the source.

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