I can't speak for ketamine, having never used it myself, but I do have experience with Ambien. Long story short, once it kicks in, your ability to remember what

I can't speak for ketamine, having never used it myself, but I do have experience with Ambien. Long story short, once it kicks in, your ability to remember what you've done is essentially nil, limited to maybe a few minutes at most (or at least that was my experience). The medical term is "anterograde amnesia". As long as you take it on an empty stomach and immediately go to bed and stay there until you fall asleep, it's reasonably safe (as long as you don't sleep walk or anything). That said, I personally recommend against Ambien, vehemently so, unless you have a family member/roommate who lives with you and can keep an eye on you while you're on it. Personal story follows: I was originally prescribed Ambien for insomnia back in 2008 or 2009 (quite a while ago!). At first it was like a miracle drug - about 30 to 60 minutes after taking it, I got sleepy and went right to bed. But after about six months on it, that changed... One day I went to fill the monthly prescription as normal - 30 tablets. I took one that night and waited for it to kick in. The next thing I remember, it was the following afternoon. The bottle with the Ambien in it was knocked over on the night stand next to my bed, lid on the floor, with two pills having slightly emerged out of the open bottle. I looked inside and to my surprise, found only 11 pills left. Out of THIRTY. So what happened? I decided to record myself that night right when I was to take the normal dose (one pill) and found that it was no longer making me sleepy, BUT I STILL COULDN'T REMEMBER ANYTHING I'D DONE, INCLUDING FORGETTING THAT I'D ALREADY TAKEN THE MEDICATION. In other words, I took the drug, didn't get sleepy, forgot I'd taken it, and took another. Lather, rinse, repeat. The next day I was down to 3 pills. Moral of the story: the anterograde amnesia caused by Ambien can be extremely dangerous and lead to overdose if you're not careful, so if you're going to use it, make sure you have somebody who can watch you to make sure you don't OD on accident. Thankfully I had zero consequences from that accidental OD - nothing bad happened thankfully - but I was a lot younger and in better health back then; if that happened today, I'm not so sure I'd have emerged unscathed. If you want to try something in that class of drug, talk with your doctor about Lunesta and/or Sonata first. The former causes a weird strong metallic taste in the mouth for some people (myself included), but AFAIK isn't nearly as dangerous. I've heard people have good luck with Sonata as well, but in my case it doesn't work for me at all for some reason (my body just doesn't process it I guess...). There are a lot of other RX medications for sleep you can try too, so talk with your doctor before jumping to any conclusions. But I still recommend putting Ambien at the bottom of your list because it's definitely not safe for everybody.