Reddit mentions of Kirkland Signature Nighttime Sleep Aid (Doxylamine Succinate 25 mg), 192 Tablets

I only take 1/2 a pill but its says to take a whole one. It's an antihistamine, like Benadryl, but it works better. They have it on Amazon if you aren't a Costco member.

The first time I went to Europe I had no problem sleeping but I was also drinking a lot so I think that made me crash. The second time I went I didn't sleep more than an hour for the whole first week. It was such a waste and I can't even describe how bad it felt. Plus if you take one on the plane you might actually sleep and feel refreshed when you land instead of starting out feeling like crap.

Sounds pretty standard to me - The active ingredient in ZzzQuil is Diphenhydramine HCI, which is a popular antihistamine, marketed as both allergy medication (smaller doses) and sleep aid (higher doses).

Branded stuff is expensive- you'd be better off getting a generic. I buy this when I want diphenhydramine. Two pills (or 50mg) is the standard dose for sleeping - same as the ZzzQuil.

I work swing shift (1:45PM-10:15PM) so I hear you on the sleep. I'm a notoriously bad sleeper- I'm finicky, I wake up every hour or so, I have to wear earplugs and have white noise and drug myself... to start. I also have pretty mild reactions to medication, so where a lot of sleep aids will cause my partner to be dead to the world for 48 hours, I might get slightly better sleep than I would've elsewise.

I prefer trazodone, which is an old antidepressant which has an off-label use of sleep aid. I do have dysthymia (chronic, but mild, depression) so that is pretty ideal for me, but I've been doing without an rx for it for a while. It helps get you to sleep but it doesn't knock you out.

So far as stuff you can access without a doctor - I've found that while diphenhydramine helps me get to sleep, it's not a "knock-me-out" kind of sleep aid, which is nice. It's not quite as good as the trazodone, but if you're generally a good sleeper (which it doesn't sound like you are) it's probably sufficient. (Again, this stuff is cheap.)

You could also try taking a melatonin supplement before bed. I'm not entirely sold on how it works (or whether it's placebo effect) but my dad has had decent luck with it. I've used it too, only problem is that it makes me far more aware of my dreams, and what dreams I do remember are kind of fucked up. I understand that's not unusual for melatonin. It isn't habit-forming but I've noticed it does get less effective as time goes on.

Most recently I've been using Doxylamine Succinate... it's more apt to knock me out than the above, though I can still get up for work easily enough the next morning. This is my "heavy hitter" right now, though it may just be because I'm not used to it yet.

If you haven't already, consider getting some blackout curtains, earplugs, and white noise (I use an in-room air conditioner on fan).

Doxylamine Succinate.

It's the shit in Nyquil that puts you to sleep. It's dirt cheap when you buy it in tablet form (and without all the other crap in Nyquil). Half a 25mg tablet will put most people into a deep sleep in under 20 minutes.

My only advice is to not take it unless you're ready to sleep right then. Unlike other sleep aids like melatonin, the DS tab won't facilitate a state of sleepiness, it'll shut you the fuck down.