Positives

• A patient with Long COVID found that using famotidine in combination with cetirizine significantly helped resolve their persistent itching and “tamed the cytokine activity” Mayo Clinic Connect.
  
  
• One person with Long COVID reported that famotidine, as an H2 antihistamine, was part of a regimen that “helped significantly” in managing their symptoms Mayo Clinic Connect.
  
  

Negatives

• One patient expressed frustration over the difficulty of obtaining famotidine in the UK without incurring “absurd prices” Reddit.
  
  

Hurdles & Side Effects

• Pepcid AC Maximum Strength 20mg is sold OTC at Costco for $13.49 per 100 tablets, and generic famotidine 20mg can drop to about $5 per fill with a SingleCare or GoodRx coupon at Walmart, CVS, and Walgreens.
• Long COVID/MCAS protocols often push to 40mg twice daily or higher, and one Inspire mast-cell community member said they had to drop back from 40mg twice daily to 20mg twice daily because the higher dose caused nausea and stomach upset before they felt better within 24 hours Inspire.