After many phone calls today, I have learned that there is a world-wide shortage of the ingredient, Diamine Oxidase or "Daosin". In the past I found alternate brands like "Histamine Block" but suddenly all of the prices got jacked up and then the products disappeared (from Amazon, Swanson, Seeking Health, etc). Today I made some calls and learned there is a world-wide shortage of this ingredient. I no longer take the bucket-load of MCAS meds that I did in 2015 b/c I don't need them. But I had continued to take Daosin (in some form) along w/my 4 main meds b/c I did not want to mess with something that was working so well. I stopped it about a week ago (b/c the product unavailable) and noticed some return of symptoms. Nothing to the dangerous/anaphylaxis level, and sometimes nothing at all, but I definitely feel better when taking some form of Daosin prior to eating food. The only company that seems to have this product is: http://umbrelluxdao.com/ I was wondering if any other MCAS peeps have heard of this brand or purchased it before? Am very curious how there is a world-wide shortage but one company can still get the ingredient? This makes me hesitant to buy it. I am okay without it but would continue taking it if given the chance. Thanks in advance to anyone who knows anything about this!