Positives

• Some Long COVID patients have explored losartan based on the ACE2/microclot hypothesis that SARS-CoV-2 infection downregulates ACE2, leaving angiotensin II signaling unopposed; some report symptom benefit on the regimen PMC.

Negatives

• Long COVID patients given losartan in outpatient and hospitalized settings reported no symptom benefit, and the hospitalized cohort had to be stopped early because of significantly higher rates of serious adverse events and hypotension ScienceDaily.
• On WebMD, one patient reported developing severe dizziness and inner-ear problems that persisted for weeks after stopping losartan, and another described feeling worse on it than off WebMD.

Hurdles & Side Effects

• Losartan’s biggest practical caveat is hypotension — many Long COVID patients with overlapping POTS already run low blood pressure, and adding an ARB without close monitoring can worsen orthostatic symptoms PLOS One.