Drugs like melatonin and African dream herb can cause strange dreams.

When I first took melatonin 10 mg, I had two nightmares. In one, I was in a shower and there was soap everywhere. I began slipping all over the place and I grabbed onto a hand towel hanging from the shelf pole. I was still slipping. For some reason I tried to write a suicide note on the towel.
In the other nightmare I was in the lounge area of one of the school buildings on campus. It was night time and I was stuck to the ceiling. I had to roll away from the fire alarms because they were cooking me with microwaves.
When I woke up I experienced sleep paralysis and felt like I was having a psychedelic flashback. Then I started flying around campus somewhere and there was lots of snow.

I decided to take melatonin an second time. I had a vivid dream that took place in a shopping mall. In one area there was a salon out in the open. In another area there were green metal bathtubs shaped like exotic plants in the display windows. In yet another area there was a bestbuy type store and one of the rooms had a VR headset attached to an xbox 360 controller. The graphics were awful as was the viewing range, and I struggled to keep my eyes open.