Well not really. Peptides are short chains of amino acids which help tell your body how to behave. We get peptides in food and they are made in our body's.
In fact, when you have a thought a peptide is created. Peptides make people feel good or bad as well as other emotions. For example Endorphens are released when we have a pleasurable experience like exercising. There are also exorphens which are found in foods and plants such as potatoes, grains and marijana.
That's right, we can make the THC like structures in our own brains based on our thoughts and experiences.
The next time you go to the supermarket watch how people are addicted to bread (grain) and potatoes. These foods are called "comfort food". Even cats like to get high by eating catnip for the same reasons.
So you better watch what you think or you may be getting stoned the natural way.