I'd like to block histamine 2, but avoid blocking histamine 1. when i block H1, i get heart palpitationons and rises in BP. I have tried pepcid but it gives me a stomach ache and I cannot try tagamet since supresses mao-a further. I also checked the 3rd one people talk about, but it has ingredients it can't have. I then looked into the mast cell stabalizer keto....but it also blocks histamine 1 and i believe cromylyn sodisum also blocks H1. when i look for natural alternatives to pharma, i see a bunch on classic histamine (H1) and on mast cells (like taking quercitan) but nothing on H2. Just feel like if i can find that, perhaps i can tolerate more foods. And that in turn will help me gain much needed weight (can't stop losing). Pehraps part of a plan to try to heal gut as one arm of this octopus beast. Thanks.