If you are looking for an anecdote, I can give you one, but individual variability will ultimately rule-the-roost here, in terms of efficacy and side effects. Maybe it might be advantageous to Google the product monograph. Usually clinical trials are briefed there. These might give you a better idea of what's possible across the board, but will also detail mechanism of action, metabolism, etc.
In terms of side effects, I never look at these before trying a drug. I'm terribly "contagious" to printed "side effects". LOL. Soooo, usually too quick to x-nay a drug when I think I might be developing one of them. I also seem to be somewhat of a Queen of Side Effects even if I can stay from away knowledge to do with potential adverse reactions. *Sigh* :-) :-).
I've tried amitriptyline, nortriptyline, and trazodone. Trazadone: "paradoxical effect". Made my insomnia way worse...and it was already pretty bad--not sleeping for days and such. I tried it for two weeks and by that time I was picking non-existent bugs out of the air from lack of sleep :-) :-). Kidding, but IF you have insomnia, you catch my drift :-).
Nortriptyline (10 mg) gave me a panic attack. Never want to feel that again. Another paradoxical effect. People who have organic panic/anxiety? Man, I would DO NOT want to be you. That glimpse was enough. Anyway, the Amitriptyline (10 mg) increased my sex drive to an uncool level. And, where sex is concerned, for most people, this might NOT be a problem.....ummmm, right? But, let me just say that it got to the point where that was all I thought about, very difficult to think of anything else. I was a prowler, sex-addiction group member, in the making, man. LOL. Weird feeling though, 'cuz I knew those thoughts weren't mine. Anyway, after the second week of that nonsense, my mood changed, and I just became VERY sad, for no apparent reason. Amitriptyline and the closely related Nortriptyline, are definitely not for me. BUT, both are typically well tolerated by most people and it IS a popular choice for chronic insomnia.
Typically 1-2 weeks are needed for it to kick in. Perhaps, you can do a "drug interactons" check (there's tons of them abound) or call the pharmacy, make sure, Gravol, Tylenol PM, or Chlor-Tripolon doesn't interact with the dose of amitriptyline you're taking. Perhaps, you may wish to take one of these drugs alongside the amitriptyline for 1-2 weeks, until the stuff starts working for you.
I hope it works for you, man. Insomnia is awful.
Have you tried Imovane? I have had more success with it than much else (~7.5 mg, I think--too lazy to check). Kinda get "rebound insomnia" if I don't take it the following night, but I find if I DO take it everyday, I get incredibly fatigue, then tolerance is an issue. These things are mediated by a GPCR, so best to take it only 4 times a week, max. You might choose to take it 4 days during your work week, take a break, suffer on the weekend (or, just sleep in if you can't sleep). Or, take it every second day during the week. Key is to avoid tolerance, though.
Good luck. Hope you can get some good sleep soon :-) :-). Lack of sleep can make ya feel like you're going crazy. Been there ;-).