Guanabenz (pronounced GWAHN-a-benz, sold under the trade name Wytensin) is an alpha agonist that is selective to the alpha-2 adrenergic receptor.

[1][2] The most common side effects during guanabenz therapy are dizziness, drowsiness, dry mouth, headache and weakness.

[3] Guanabenz can make one drowsy or less alert, therefore driving or operating dangerous machinery is not recommended.

[4] Guanabenz was found in one study to exert an inhibitory effect by decreasing the abundance of the enzyme CH25H, a cholesterol hydroxylase linked to antiviral immunity.

Therefore, it is suggested that the drug and similar compounds could be used to treat type I interferon-dependent pathologies and that the CH25H enzyme could be a therapeutic target to control these diseases,[5] including amyotrophic lateral sclerosis.