This isn't an experiment, nor has it been recommended by Bear Grylls. That's it. I have ruled out two of your fears. If you are more paranoid than this and believe that it leads to a complex combination deadlier than Hemlock, this post isn't for you.
But for the rest of you who are less paranoid and think a little lesser than Hemlock, read on.
Ingredients: 1 organic banana (with peel), 1 small pot of water, sprinkle of cinnamon (if you'd like)
Step 1: Cut off both ends of the banana (top and bottom)
Step 2: Put the banana into a pot of water. If the water is spring water or purified in some way, even better! Boil for about 10 minutes.
Step 3: Sprinkle some cinnamon into the water as well. If you'd like to add some stevia for sweetening, do so. Stevia helps to balance blood sugar levels, and will not spike blood sugar levels before bed.
So, give it a try! Boil and banana and drink the water before bed, you will have amazingly healthy sleep.