O's are compounds that positively effect the natural O neurotransmitter system. Menthol is the most well known and consumed O commonly found in mint teas and otc medications. Casomorphin is a natural protein found in milk. Mitragyna speciosa is also a popular plant widely used in the US and Asian countries. These compounds are best used as needed for quick acting mood enhancement or Pain modulation and recommended to be used as needed or cycling off on weekends.