From what I've seen first hand multiple times; Diphenhydramine will worsen some withdrawal symptoms, especially RLS, which I get really bad, if you do not wait at least 4 or 5 days to do it. Maybe more for some people. The problem is that when people are still in the worst of the shit storm, you want to do almost anything to get rid of the chills, shakiness, RLS, etc. So then they will take a sleep aid like Diphenhydramine and just worsen the RLS. This ends up leading to people on hundreds of forums claiming this drug is no good for wd. For me personally, an aleve or two and 40-60 mg of loperamide does wonders. However, the insomnia and RLS will continue, sometimes for weeks. Best thing to do imo is to do whatever you can to get thru the worst of it, if you can do that and all you're still experiencing is some RLS and insomnia, and your 5 maybe 6 days in, try the Diphenhydramine. Larger doses have also been reported to be one reason RLS may get worse, so start small, under 50mg, and see how it affects you. My girlfriends brother swore that the Diphen helped him get sleep more than anything after the first week of heroin wd. He said it made it worse when he tried it on like day two or three. Me personally, Im about to see how it helps me with my heroin wd, as I am about 5 days in since any opiate, however I greatly reduced my tolerance over the last 3 weeks and had only 2 relapses. My withdrawal is no longer as bad after 24-48 hours and by day 3 and 4 my RLS is really the only thing that has been driving me crazy and keeping me awake for days. So I'm taking my friend and gf's bro's advice and trying the Diphenhydramine for this horrible insomnia that's driving me mad. Point is, don't assume diphen doesn't work for wd's because people who couldn't wait long enough took it and felt worse. There's still a good possibility that it can work for post-acute withdrawals. I'm no expert, but I've done opiates for almost a decade, with a brief period of no opiate usage that lasted 3 or 4 years, then recently went back into it after having severe tooth pain that only went away with the use of oxycodone. That got too expensive once my meds ran out, and after 6 months went back to the H that I thought I would never do again and just went a good year straight going hard with it. Now that my kid was just born I'm deciding to be done with it once again, this time for good. Loperamide, weed, naproxen, benzo's, kratom, akuamma, suboxone, and gaba pentin have been my saviors the last 3 weeks. If your going through withdrawal, any of the things listed will help a lot in combination with each other, not all at once. I used them very strategically, this isn't my first rodeo. Please be careful