Reviewed by the HeyPsych Medical Review Board
Board-certified psychiatrists and mental health professionals
Clinical summary for Guanfacine (Intuniv): Guanfacine (Intuniv) is a non-stimulant used to help ADHD symptoms like impulsivity, hyperactivity, and emotional “overdrive,” especially when stimulants aren’t a great fit or tics/Tourette’s are involved. It can also be used alongside a stimulant. The tradeoff is sedation and cardiovascular effects like low blood pressure and slower heart rate. Don’t stop it suddenly—withdrawal can cause rebound hypertension and nervous, agitated symptoms.
Guanfacine is one of those meds where the “feel” can be the whole story—because the same calming effect that helps ADHD can also make you sleepy or lightheaded.
Calmer Body, Quieter Reactivity
"It didn’t hype me up. It just made me less… spring-loaded."
This is not a “take it and feel it in 30 minutes” medication for ADHD symptoms. The behavioral benefits build over time, while side effects (especially sleepiness and dizziness) can show up early.
Intuniv (guanfacine extended-release) is used to treat ADHD—especially symptoms like hyperactivity, impulsivity, and emotional overreacting. It’s often considered when stimulants cause side effects, don’t work well enough, or aren’t a good idea due to diversion/misuse risk. It can be used alone or alongside a stimulant.
No. Guanfacine is not a stimulant. It’s an alpha-2A adrenergic agonist that tends to calm and steady the nervous system rather than “rev it up.”
The ADHD benefits usually build over days to weeks, especially as the dose is slowly titrated. Side effects like sleepiness and dizziness often show up earlier—sometimes within the first few days and after dose increases.
Because it reduces norepinephrine signaling in a way that can lower arousal. That can be helpful for wind-down and impulsive overactivation, but it can also cause daytime drowsiness—especially early in treatment or at higher doses.
For some people with ADHD, yes—mainly because sedation can be a side effect. If sleepiness is the main benefit, dose timing (evening dosing) sometimes helps. The goal is controlled calm, not being knocked out.
Yes. Guanfacine ER can be used as an adjunct to stimulants. This combo is often used when stimulants help attention but impulsivity, emotional reactivity, or rebound symptoms still break through. Blood pressure, heart rate, and sedation should be monitored.
It can for some people, especially when ADHD is also present. Results are mixed across studies, so it’s not a guaranteed tic medication—but it’s commonly considered in the tics + ADHD overlap zone.
Don’t do it. Abrupt discontinuation can trigger withdrawal symptoms and rebound hypertension (a blood pressure spike). People may feel jittery, anxious, agitated, get headaches or tremors, and have a noticeable rise in blood pressure. Tapering is the safer move.
Missed doses matter because of withdrawal/rebound risk. If you miss two or more consecutive doses of extended-release guanfacine, clinicians often consider restarting at a lower dose and re-titrating rather than jumping right back to the previous dose.
It’s a bad idea. Alcohol can stack sedation and dizziness and increase the risk of fainting or falls. If alcohol is part of your life, talk about it directly so dosing and timing can be safer.
Because guanfacine reduces sympathetic tone. That can lower blood pressure and slow heart rate, sometimes enough to cause dizziness, orthostatic symptoms, or fainting—especially early on, after dose increases, or with dehydration.
No. Immediate-release and extended-release guanfacine are not interchangeable mg-for-mg. They have different pharmacokinetics and exposure profiles. Switching between them should be done deliberately with a clinician’s plan.
Yes. Grapefruit can increase guanfacine levels, which can mean more sedation and more blood pressure/heart rate effects. Many clinicians recommend avoiding grapefruit products while taking guanfacine.
This medication information is for educational purposes only and is not a substitute for professional medical advice. Always consult your healthcare provider before starting, stopping, or changing any medication. Never take medication without a prescription from a licensed healthcare provider.
This information is for educational purposes. Always consult with a qualified healthcare provider before starting any new treatment.