Beyond the realm of prescription drugs are over-the-counter and herbal alternatives.
Regarding the former, most options include an antihistamine.
Diphenhydramine is a popular choice, found in the U.S. under the brand name Benadryl.
While it seems like these would be inherently less troublesome than, say, a habit-forming benzodiazepine, we still know very little about the risks of using medications like Benadryl for sleeping purposes.
What we do know is as follows: that tolerance for antihistamines builds up quickly so they rapidly become less effective and that it is indeed possible to fatally poison yourself with this type of drug.
Herbal alternatives seem safer by virtue of being natural, but that’s not necessarily true.
Some herbal supplements have been known to cause organ troubles (see the FDA’s 2002 advisory about kava), as well as adverse interactions with other drugs.
Within this category, melatonin and valerian root are commonly used combat mild insomnia, but they may not be as effective in more dramatic cases. For melatonin, data suggests that around five percent of the U.S. population may be utilizing it.
But as the FDA still classifies it as a dietary supplement and not a drug, information on its usage and side effects remains somewhat anecdotal.
However, a 2013 report in PLOS ONE suggests that it is in fact useful in improving sleep quality.