Back to Guanfacine (Intuniv)

Safety question

Is Guanfacine (Intuniv) safe?

Generally yes, with attention to dose and timing. Guanfacine (Intuniv) scores 4/5. Adverse reactions are uncommon, minor, and reversible on stopping. The main risks are dose-related — starting at the low end of the clinical range and titrating up gives the best safety margin.

Safety score

4 / 5

Evidence grade

A

Severe reactions on file

0

Pubmed cites

1400

Key facts

typical dose
1–4 mg
dose frequency
1 dose
timing
evening
with food
optional
onset
120 minutes
half-life
18 hours
safety score
4/5
evidence grade
A
class
stimulant
PubMed citations
1400
legal status (US)
Prescription-only
legal status (UK)
Prescription-only
legal status (EU)
Prescription-only
legal status (AU)
Prescription-only
primary mechanism
Selective alpha-2A adrenergic receptor agonist concentrated in prefrontal cortex.

Common side effects

Uncommon side effects

Who should not take Guanfacine (Intuniv)

What "safe" means here

Our safety scoring reflects (a) published clinical and observational literature on healthy-adult use at standard supplement doses, (b) the spectrum of adverse-event reports in the medical and supplement-pharmacovigilance record, and (c) the regulatory status across major jurisdictions. It does notreflect long-term outcomes in populations that haven’t been studied, and it does not substitute for clinical judgement applied to your individual situation.

A 5/5 score does not mean “no risk” — it means risk has been quantified as low in healthy adults at usual doses. Idiosyncratic and allergic reactions are possible with virtually any compound, including those we rate highest.

Full mechanism, citations, and dose guidance for Guanfacine (Intuniv) are on the main reference page — see Guanfacine (Intuniv). For the dose-by-dose breakdown, see Guanfacine (Intuniv) dosage. To check stack interactions, use the interaction checker.

This page is informational. It is not medical advice and does not establish a clinician-patient relationship. Individual risk varies with genetics, medications, pre-existing conditions, and dose. Always consult a qualified clinician before starting a new compound. See our full disclaimer and terms.