"Good" is a pretty loose category. Some drugs are very effective, but come with siginficant side effects, or lose their efficacy quickly due to tolerance buildup and are potentially addictive. It's also a matter of your personal response to each drug, of course, and of what your demands for a sleeping aid are - to aid in falling asleep, or in maintaining sleep, or both?
Some of what I have considered very effective drugs for inducing sleep (my main issue, not staying asleep, or falling back asleep if disturbed) that I have used each at least a handful of times, many for prolonged times:
- Benzodiazepines and nonbenzodiazepines, particularly temazepam, nitrazepam, flunitrazepam, lormetazepam, and zopiclone and zolpidem.
- Low doses of neuroleptic drugs such as quetiapine, olanzapine or levomepromazine. The tricyclic depressant amitriptyline has also worked.
- GBL or GHB.
- Tizanidine (Zanaflex, Sirdalud among other trade names), a skeletal muscle relaxant.
- Heavy doses of opioids also reliably induce sleep, but are obviously not an appropriate choice here.
The following have been moderately effective:
- Cannabis, except for when I was younger, when it reliably knocked me out
- Alcohol, especially when combined with cannabis - although obviously drinking enough will make you pass out eventually.
- First-generation antihistamines like hydroxyzine, diphenhydramine
- Mirtazapine, an anti-depressant.
All have various side effects, risks, and other properties that make them suitable for different purposes - long or short term use, or only sporadic, emergency use. They differ in whether or not you can rely on them if you have shit to do tomorrow. Some are addictive, some can be dangerous. Unfortunately, the most efficient ones tend to be the more 'hard' ones, and the ones that are more poorly suited to regular use. I have thankfully shaken off my need to regularly use stronger stuff to get to sleep. Mainly through lifestyle choices and investments in my sleeping environment.
