There's no doubt that cannabis can have a range of effects on sleep, as it has been proven to not only help us fall asleep faster but also stay asleep longer and experience a more restful sleep cycle. It doesn't matter if you suffer from the occasional wakeful night or chronic insomnia, marijuana is a natural sleep aid that nearly every cannabis user has turned to at one point or another. If you're considering using cannabis as a sleep aid, chances are one of your next questions is whether indica or sativa strains are better for sleeping.
The short answer is that indica cannabis strains are usually a better sleep aid than sativas, which are typically thought of as more energizing marijuana varieties. We don't have scientific evidence why indicas are better for sleeping (differences in genetic makeup, terpenes, etc.), but it is generally agreed that their effects are usually more relaxing and sedative than those of sativas. However, the most potent indica strains have high content levels of tetrahydrocannabinol (THC), which can have an adverse effect on sleep and exacerbate one's anxiety and insomnia.
This is just part of what makes knowing whether an indica or sativa will be better for sleeping a very personal, subjective question. We can't forget that everyone experiences cannabis differently and that other factors come into play when considering indica and sativa marijuana strains as sleep aids.
For example, older, dried out cannabis is better for sleeping than freshly harvested flowers. This is because some of the THC has had time to degrade and convert to the compound cannabinol (CBN), which is a much stronger sedative than THC. Also, marijuana strains with high content levels of non-psychoactive compound cannabidiol (CBD) counteract THC-induced anxiety. The way you consume cannabis can affect sleep, as ingesting marijuana-infused products take longer to take effect, are more intense, and last longer than also last longer than inhaling smoke from the herb.
To end, knowing if an indica or sativa is better for sleeping depends on many things, including your personal needs and how a certain strain affects you. For now, we can only suggest that an indica is better than a sativa for sleeping, but you'll have to judge for yourself.