It's an empathogen drug. It makes you release high levels of serotonin at once which causes feelings of tranquility, peace, wellness, love and bliss.
It's in the late stages to become an approved therapy drug because it helps people with PTSD and trauma better than any other treatment. Sometimes people recover after many years of PTSD after just one treatment.
At the moment it's often used as a party drug because it majorly enhances emotions. People will take it before seeing their favorite band for example to ensure it'll be the best concert of their lives.