What Is Guanfacine? Uses, Dosage, and What You Need to Know in 2026

Guanfacine is a prescription medication used to treat attention deficit hyperactivity disorder (ADHD) and high blood pressure (hypertension). It's one of the few non-stimulant options for ADHD and is often chosen for patients who cannot tolerate or don't respond well to stimulant medications like Adderall or Ritalin.

Brand Names and Generic Names

Guanfacine is the generic name. It's available under two main brand names:

Intuniv: The extended-release (ER) formulation, approved for ADHD in children and adolescents ages 6–17. Available as 1 mg, 2 mg, 3 mg, and 4 mg tablets. Generic versions are widely available.

Tenex: The immediate-release (IR) formulation, originally approved for hypertension. Brand Tenex is no longer manufactured; generic Guanfacine IR (1 mg and 2 mg tablets) is available.

What Is Guanfacine FDA-Approved For?

Guanfacine has two main FDA-approved indications:

ADHD (Guanfacine ER / Intuniv): FDA-approved in 2010 for the treatment of ADHD in children ages 6–17 as monotherapy or adjunctive therapy to stimulant medications. Off-label use in adults with ADHD is common.

Hypertension (Guanfacine IR / Tenex): FDA-approved in 1986 for adults with high blood pressure, used alone or with other blood pressure medications.

Common Off-Label Uses

Beyond its FDA-approved indications, Guanfacine is commonly prescribed off-label for:

Adult ADHD (not formally FDA-approved but widely used)

Anxiety disorders, including generalized anxiety disorder (GAD)

Post-traumatic stress disorder (PTSD), particularly nightmares and hyperarousal symptoms

Tourette syndrome and tic disorders

Opioid, nicotine, and alcohol withdrawal support

Is Guanfacine a Stimulant?

No. Guanfacine is not a stimulant and is not a controlled substance. This distinguishes it from first-line ADHD medications like Adderall (amphetamine) and Ritalin (methylphenidate). Guanfacine works through a completely different mechanism and has no abuse potential or DEA scheduling.

Guanfacine Dosage and Forms

Guanfacine comes in two formulations with different dosing:

Guanfacine IR (for Hypertension)

Available as 1 mg and 2 mg immediate-release tablets

Typical starting dose: 1 mg at bedtime; may increase to 2 mg after 3–4 weeks

Maximum: 3 mg/day

Take at bedtime to minimize daytime drowsiness

Guanfacine ER (for ADHD)

Available as 1 mg, 2 mg, 3 mg, and 4 mg extended-release tablets

Starting dose: 1 mg once daily; dose is weight-based (0.05–0.12 mg/kg/day target)

Dose adjustments: no more than 1 mg per week

Maximum: 4 mg/day for ages 6–12; 7 mg/day for ages 13–17

Take once daily, consistently at same time; do NOT take with high-fat meals

Swallow whole — do NOT crush or chew ER tablets

Important Safety Points

Never stop abruptly: Rebound hypertension risk. Always taper under medical supervision.

Monitor blood pressure and heart rate: Before starting and periodically during treatment.

Avoid high-fat meals: With ER formulation; can increase absorption rate and risk of side effects.

Pregnancy: If pregnant and taking Guanfacine ER, register with the National Pregnancy Registry for ADHD Medications: 1-866-961-2388.

How Long Does Guanfacine Take to Work?

For ADHD, it may take 2 weeks or longer to notice the full benefit of Guanfacine ER. Blood pressure effects from the IR formulation typically begin within a few days. Dose adjustments are made gradually to balance effectiveness and side effects. For more on how Guanfacine works, see: How Does Guanfacine Work? Mechanism of Action Explained.