An opioid is a medication prescribed to relieve moderate to severe pain by weakening pain signals from nerves to the brain. Traditional opioid medications, such as oxycodone, codeine and morphine, are derived from a specific species of poppy plant. The opioids activate part of the body’s opioid system in order to relieve pain. However, there are other naturally-occurring and non-opioid substances that also act on the opioid system to relieve pain. These substances, known as opioid peptides, are either found in nature or produced by the body.
Examples of opioid peptides include the following:
- Mitragyna speciosa alkaloids (Kratom) are substances from tropical, evergreen trees in the coffee family. They are composed of opioid-like molecules. The two chemicals in kratom, mitragynine and 7-hydroxymitragynine, have a strong effect on the body’s main opioid receptor.
- Salvinorin A and Collybolide are selective kappa-opioid receptor agonists. Salvinorin A, acquired from a species of Mexican sage bush, and collybolide, derived from Collybia maculata mushrooms, have extremely similar structures. Both substances work on opioid receptors.
- Beta-casomorphin is an opioid peptide that is produced in the body’s gastrointestinal tract by transforming specific proteins into amino acid chains that interact with opioid receptors. They are developed from digesting bovine or human milk.
The impact of these naturally-occurring substances on the body’s opioid receptors makes them a potential source for future pain treatments. However, use of opioid peptides found in nature may have negative side effects. Additional research is needed to understand how opioid peptides may be safely used to treat pain.