Is it safe to take doxylamine for insomina on a regular basis for months?

Do you need to?: That's a better question, and the follow up is why do you need it? The drug itself is similar to Benadryl (diphenhydramine) with similar side effects. It's never wise to take sleeping aids for long term without looking for an underlying cause for the sleep problem. I would suggest yo speak to your doctor about your sleep problems and see if you can find out what's causing you to not sleep well in the first place.