Guanfacine: Side Effects, Uses & Monitoring
Guanfacine tablets, USP are indicated in the management of hypertension.
- Data source
- FDA labeling via NIH DailyMed (label a81b956b…)
- Label version
- current
- Last reviewed
- 2026
Reported adverse reactions
Reactions listed in current FDA labeling, with the highest frequency reported across summarized placebo-controlled trials.
| Adverse reaction (as reported in labeling) | Reported frequency* |
|---|---|
| Dry mouth | 54% |
| Somnolence | 39% |
| Drowsiness | 33% |
| Percent dropouts | 32% |
| Dizziness | 15% |
| Constipation | 15% |
| Headache | 13% |
| Fatigue | 10% |
| Asthenia | 7% |
| Impotence | 7% |
| Weakness | 5% |
| Insomnia | 4% |
*Highest percentage reported for the active moiety across placebo-controlled trial tables in current FDA labeling. Values reflect trial reporting, not your individual risk.
Labeled uses (from FDA prescribing information)
Guanfacine tablets, USP are indicated in the management of hypertension. Guanfacine tablets, USP may be given alone or in combination with other antihypertensive agents, especially thiazide-type diuretics.
Conditions associated with Guanfacine in labeling
Frequently Asked Questions
What is Guanfacine used for?
FDA labeling lists the approved uses shown above under "Labeled uses." This summary is informational; only a qualified prescriber can determine whether a medication is appropriate for you.
What are the most commonly reported side effects of Guanfacine?
The table above shows adverse reactions and the highest frequencies reported in placebo-controlled trials summarized in current FDA labeling for Guanfacine. Individual risk varies.
Does Guanfacine require lab monitoring?
Monitoring needs vary. Ask your healthcare provider whether any lab tests apply while taking Guanfacine.
Where does this information come from?
All clinical facts on this page were extracted from the current FDA-registered product labeling for this ingredient, published by manufacturers through NIH DailyMed. See the source link below.
Medical disclaimer: Educational content extracted from public FDA labeling. Not medical advice. Always consult a qualified healthcare professional before starting, stopping, or changing any medication.