The specific drug studied was diphenhydramine (Benadryl), which Ray Peat recommends for several problems including endotoxin protection and liver support. http://psychcentral.com/news/2013/10/23 ... 61082.html http://www.pnas.org/content/early/2013/ ... l.pdf+html However, I have seen pretty similar results for cyproheptadine, which is also antihistamine in action. http://www.ncbi.nlm.nih.gov/pubmed/9606583 http://www.ncbi.nlm.nih.gov/pubmed/10964879 So, it seems that this may be a general property of the antihistamines. I wonder what the mechanism of action is. Based on Peat's ideas anxiety/PTSD/panic are probably caused by serotonin so that explains why cyproheptadine is effective since it's a general serotonin inverse agonist. But if Benadryl is working as well, then does that imply Benadryl has anti-serotonin action as well??? Maybe somebody already exchanged emails with Peat on Benadryl and how he thinks the drug achieves its effects. So, please share what you know.