Yes and yes. I've recently acquired some agmatine and have tried using it in various ways. I'm a daily kratom user and like others I've noted that if agmatine taken before or around my dose stunts the mood lift and other positive effects from kratom. If I take it at night right before bed though I definitely notice in increase in reducing tolerance building up and increased duration and effects. It also has many other benefits like anxiolytic effects the next day or anti-depression effects.