Periactin is an antihistamine which has sedating effects and some studies show it increase stage 4 deep sleep. I have been using either zopiclone or zolpidem to initiate sleep with periactin for sleep maintenance no more than every second night and its giving me a good 8hrs sleep. I have used it in the past and it has helped some but eventually stopped working, so i havent used it in a long time. I think its worth while retrying things one has used in the past even if they didnt help, for some reason they can work again, maybe our physiology changes as well as taking long breaks can help reduce any tolerance that has built up. So at the moment im enjoying the good sleep im getting from it cheers!!