Treatment Database

A combination of guanfacine, an α2A-adrenoceptor agonist FDA-approved for ADHD that strengthens prefrontal cortex network function, and N-acetylcysteine (NAC), an antioxidant and glutathione precursor. Yale researchers proposed it for Long COVID brain fog after noting its resemblance to post-concussive cognitive deficits. In their case series of 12 patients (Fesharaki-Zadeh, Arnsten et al., Neuroimmunology Reports 2022), guanfacine 1 mg at bedtime, increased to 2 mg after a month, plus NAC 600 mg daily, 8 reported substantial improvement in memory, multitasking and organization. Two stopped because of low blood pressure and dry mouth, two were lost to follow-up, and the team later switched to extended-release guanfacine to reduce side effects. A 2024 case report described marked cognitive improvement on extended-release guanfacine alone. No placebo-controlled trials have been published, and a 2024 health technology assessment (WorkSafeBC) rated the evidence as low quality. Guanfacine lowers blood pressure and heart rate, which matters for people with POTS or orthostatic intolerance, and it should be tapered rather than stopped abruptly to avoid rebound hypertension.