Guanfacine: uses, dosing, side effects & brands
Guanfacine is a central alpha-2 adrenergic agonist sold in the U.S. under 2 brand and generic names, for attention deficit disorder with hyperactivity and hypertension. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Central Alpha-2 Adrenergic Agonist
- Treats
- Attention Deficit Disorder with Hyperactivity and Hypertension
- Available as
- Tablet
- Sold as
- 2 products — Guanfacine Hydrochloride and Tenex
- Prescription?
- Prescription only
- Generic available?
- Yes
- What the pharmacy pays
- about $5 for a 30-count supply — not your price
Get treated for Guanfacine conditions online
Licensed online providers — consult & get prescribed if eligible.
Advertising disclosure: We may earn a commission, at no extra cost to you. This never affects our ratings. Details
How guanfacine is dosed
From the FDA label for Guanfacine Hydrochloride (application ANDA200881). Other guanfacine products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Recommended dose: 1 mg to 7 mg (0.05 to 0.12 mg/kg target weight based dose range) once daily in the morning or evening based on clinical response and tolerability ( 2.2 ). Begin at a dose of 1 mg once daily and adjust in increments of no more than 1 mg/week ( 2.2 ). Do not crush, chew or break tablets before swallowing ( 2.1 ). Do not administer with high-fat meals, because of increased exposure ( 2.1 ). Do not substitute for immediate-release guanfacine tablets on a mg-per-mg basis, because of differing pharmacokinetic profiles ( 2.3 ). If switching from immediate-release guanfacine, discontinue that treatment and titrate with guanfacine extended-release as directed ( 2.3 ). When discontinuing, taper the dose in decrements of no more than 1 mg every 3 to 7 days to avoid rebound hypertension ( 2.5 ). 2.1 General Instruction for Use Swallow tablets whole. Do not crush, chew, or break tablets because this will increase the rate of guanfacine release. Do not administer with high fat meals, due to increased exposure. 2.2 Dose Selection Take guanfacine extended-release tablets orally once daily, either in the morning or evening, at approximately the same time each day. Begin at a dose of 1 mg/day, and adjust in increments of no more than 1 mg/week. In monotherapy-clinical trials, there was dose- and exposure-related clinical improvement as well as risks for several clinically…
Guanfacine side effects
The following serious adverse reactions are described elsewhere in the labeling: Hypotension, bradycardia, and syncope [see Warnings and Precautions ( 5.1 )] Sedation and somnolence [see Warnings and Precautions ( 5.2 )] Cardiac conduction abnormalities [see Warnings and Precautions ( 5.3 )] Rebound Hypertension [see Warnings and Precautions ( 5.4 )] Most common adverse reactions (≥5% and at least twice placebo rate) in fixed-dose monotherapy ADHD trials in children and adolescents (6 to 17 years): hypotension, somnolence, fatigue, nausea, and lethargy ( 6.1 ). Flexible dose-optimization ADHD trials in children (6 to 12 years) and adolescents (13 to 17 years): somnolence, hypotension, abdominal pain, insomnia, fatigue, dizziness, dry mouth, irritability, nausea, vomiting, and bradycardia ( 6.1 ). Adjunctive treatment to psychostimulant ADHD trial in children and adolescents (6 to 17 years): somnolence, fatigue, insomnia, dizziness, and abdominal pain ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Actavis at 1-800-432-8534 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The…
Who shouldn’t take guanfacine
Guanfacine extended-release is contraindicated in patients with a history of a hypersensitivity reaction to guanfacine extended-release or its inactive ingredients, or other products containing guanfacine. Rash and pruritus have been reported. History of hypersensitivity to guanfacine extended-release, its inactive ingredients, or other products containing guanfacine ( 4 ).
Guanfacine drug interactions
Table 14 contains clinically important drug interactions with guanfacine extended-release [see Clinical Pharmacology ( 12.3 )] . Table 14: Clinically Important Drug Interactions: Effect of other Drugs on Guanfacine Extended-Release Concomitant Drug Name or Drug Class Clinical Rationale and Magnitude of Drug Interaction Clinical Recommendation Strong and moderate CYP3A4 inhibitors, e.g., ketoconazole, fluconazole Guanfacine is primarily metabolized by CYP3A4 and its plasma concentrations can be significantly affected resulting in an increase in exposure Consider dose reduction [see Dosage and administration ( 2.7 )] Strong and moderate CYP3A4 inducers, e.g., rifampin, efavirenz Guanfacine is primarily metabolized by CYP3A4 and its plasma concentrations can be significantly affected resulting in a decrease in exposure Consider dose increase [see Dosage and administration ( 2.7 )] Strong and moderate CYP3A4 inhibitors increase guanfacine exposure. Decrease guanfacine extended-release to 50% of target dosage when coadministered with strong and moderate CYP3A4 inhibitors ( 2.7 ). Strong and moderate CYP3A4 inducers decrease guanfacine exposure. Based on patient response, consider titrating guanfacine extended-release dosage up to double the target dosage over 1 to 2 weeks ( 2.7 ).
Every guanfacine product we track (2)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
| # | Drug | Rating | Type | Form | Generic? | Pharmacy pays | |
|---|---|---|---|---|---|---|---|
| 1 | 72/100 | Prescription | Tablet | Generic | $5 | View → | |
| 2 | Not yet rated | Prescription | Tablet | Generic | $5 | View → |
What guanfacine pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
Can you crush or split guanfacine?
At least one guanfacineproduct is labelled to be swallowed whole — crushing an extended-release tablet releases the whole day’s dose at once. Which applies depends on the form you were given.
What each guanfacine label says about crushing, splitting and chewingHow long guanfacine keeps
No guanfacine label we read sets a separate limit for after opening, but they do specify how it must be stored — and the stability behind any date assumes those conditions.
Does guanfacine expire? The in-use limits and storage rules from its labelsGuanfacine and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for guanfacine: levels in milk, effects in breastfed infants, and the drugs it would consider insteadBecause no information is available on the use of guanfacine during breastfeeding and its possible negative effects on lactation, other agents may be preferred, especially while nursing a newborn or preterm infant.
National Institute of Child Health and Human Development, record revised November 15, 2024. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about guanfacine
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 1,046 reports naming guanfacine, and the FDA flagged 61% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- fatigue60 reports
- somnolence57 reports
- aggression46 reports
- insomnia46 reports
- agitation42 reports
- headache42 reports
- dizziness39 reports
- vomiting37 reports
Read these as a signal, not a rate. A report does not mean guanfacine caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved August 25, 2026.
Related calculators
Frequently asked questions
What is guanfacine?
Guanfacine Extended-Release is a once-daily, extended-release formulation of guanfacine hydrochloride (HCl) in a matrix tablet formulation for oral administration only. The chemical designation is N-amidino-2-(2, 6-dichlorophenyl) acetamide monohydrochloride.
What kind of drug is guanfacine?
The FDA classifies guanfacine as a central alpha-2 adrenergic agonist. These drugs activate alpha-2 receptors in the brainstem, which tells the nervous system to send out less norepinephrine and reduce sympathetic (fight-or-flight) signaling to the body. With less of this stimulation, blood vessels relax and heart rate slows, lowering blood pressure. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take guanfacine with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run guanfacine against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is guanfacine sold under?
We track 2 guanfacine-containing products in the U.S.: Guanfacine Hydrochloride and Tenex. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does guanfacine come in?
Across the brands we track, guanfacine is currently marketed as tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic guanfacine?
Yes. Our catalog lists 1 generic guanfacine product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Cite this page
- APA
- pharmaranks. (2026, July 24). Guanfacine: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/guanfacine
- MLA
- “Guanfacine: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/guanfacine.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for guanfacine on DailyMed (NIH) ↗.