Evening Primrose Oil seemed to help me sleep a bit more, but it was just a slight improvement. I'm not sure that it was still helping before I had to stop using it while trying to figure out what was causing me other problems.
For me, it's more of a matter of figuring out what makes my sleep worse. Physical or cognitive exertion past 2PM, and quickly-digested carbs past 2PM both give me insomnia.
The only thing that works for me reliably and with no side effects apart from mildly hung over the next day is 1mg of melatonin. It's advised not to go above 1mg because you will get used to it. Semi regular breaks of say 2 days or 3 per week are also recommended. In American you can buy liquid melatonin, this is illegal in the UK buy you can buy life extension melatonin capsules instead and use that just as effectively.
You could also try 5-htp as that worked well for me too after @Mary recommended it.
Melatonin here too. And the 1mg advice is correct but the tolerance part i don't know.
But i have been left with non 24 hour circadian rhythm disorder, i have to take it one our later each day otherwise the body clock goes haywire.
We're all different, and many would not do well with that dose of niacin, but it works for me. It does cause the niacin flush, but that's fine with me - it helps put me to sleep.
The glycine and gelatin, which is high in glycine, can be tricky because when I first tried gelatin several years ago at night for sleep (1 tablespoon), it caused a severe detox reaction. I then learned that glycine is important for Phase II liver detoxification. I then went to a very small dose, gradually increased it over 6 months, until I finally stopped reacting to it and now can take it with no detox reaction. And my detox reactions in general have basically stopped - it used to be a weekly occurrence.
So I was taking 2000 mg of glycine for several years, but recently started gelatin before bed - 2 teaspoons dissolved, and it seems to be more effective than the glycine.
All of this puts me to sleep for about 4 hours. Then in the middle of the night I take
A few more things: If your cortisol is high at night, I don't think any of this would touch that insomnia. So it might be good to get your cortisol levels checked. I think the Adrenal Stress Index Test is best - it's a saliva test which measures cortisol levels via 4 saliva samples taking during the day/evening. Most doctors only order a blood test which is done first thing in the morning which tells you nothing about your night time level. when my cortisol was found to be high at night, I was told to take Seriphos (phosphorylated serine, NOT phosphatidyl serine, not the same thing) and this worked amazingly well. I found it was best to take it in the morning (had to do with circadian rhythm). When taken at night it caused a weird awful insomnia for me, but in the morning it just calmed me down and helped with sleep hours later at night. I had to experiment, titrate up, to find out the dose I needed.
Unisom can be very helpful too - an old antihistamine - it's different than benadryl, and much more effective for me. but my body easily adjusts to it so it can lose its effectiveness in a few weeks. It's also very strong! I save it for when I absolutely have to get 8 hours, and taking 1/4 tablet in the middle of the night (along with everything else) always does the job.
And a couple of more things you might try: This post talks about a pose when done daily, worked very well for me to help with sleep. After some weeks though it started to rev up my thyroid, causing insomnia. Some time I want to try it again, and this time try cutting my thyroid med, instead of stopping the pose.
Grounding has also been helpful for me. When the weather is warm enough, I aim to sit outside with my feet on cement (no grass where I live) for at least an hour - and it helps put me back to sleep quickly. But it's too cold to do that right now.
Finally (and I think this really is my last suggestion!) - humming believe it or not is very calming. It helps produce nitric oxide and can switch you from sympathetic to parasympathetic. I've been combining humming (Ommmm or just mmmmm) with the box breathing - (1) inhale, (2) hold breath; (3) exhale while humming; (4) hold breath again, all the while inhaling and exhaling through your nose, no mouth breathing! - see above link.
as wishful says the best thing for me has been to figure out what is stopping me from sleeping and for me it was eating carbs after 6pm, anxiety, and also for some reason sleeping under synthetic fibres - I guess because my body doesn't sweat properly I need my covers to breather properly, bizarrely though, a weighted blanket also helps - the fine line is really odd. I do now use 1.5mg of melatonin, I think I've got dependant on it, but I don't seem to be building tolerance and I generally sleep well if I do the things I've mentioned. Other things that help are cannabis, but I find it annoying in that sometimes, randomly, it can make anxiety worse.
I'll add in another unexpected cause of poor sleep for me: proline. For a year or more I'd been waking multiple times during the night. Waking every 90 minutes was quite common. When I discovered that proline was making my ME symptoms worse, I reduced the amount of proline in my diet, and my sleep periods went up to 2-4 hours. I'm not claiming that everyone is sensitive to that amino acid, but there may be something in your diet that affects your sleep. Proline was tough to figure out, since it's in almost all foods, and the responses to it weren't immediate.
Likewise, there may be activities you do every day that affect your sleep. Maybe reading messages here in the morning does something that results in waking the next morning at 2AM. Maybe brushing your teeth before bed does it. If you do those same activities every day, how do you know that they aren't having an effect? You can try shifting at least the time you do such things, to see if it has any effect.
Of course, changing a strongly-held habit, such as going to bed without brushing/flossing, can possibly screw up your sleep too.