I lodged for a time with a family who were very into 'herbal' supplements. But they weren't drugs, they said, these were 'natural' from plants. For some reason they objected to me suggesting that I bring some other natural plants into the house, I believe I suggested cannabis and opium...

At their suggestion I tried one of their 'natural' supplements which "helps you sleep". It did, indeed -- until they ran out of it, and I was awake for three days straight...