Simple molecular structure of melatonin, a hormone utilised in the human body to regulate sleep-wake cycles(among other things).  It was first discovered in 1958 and isolated from a substance from cow pineal glands that could induce skin lightening in frogs(weird).

In the Fusion 360 file you can change dimensions, thickness and more by changing the parameters.

Roughly 76mm long.

Check out my other molecules! 

https://www.printables.com/@Springytails_2177024/collections/3248832