NPA can generate negative effects… but you must take into account all pheremones do. The way I see it.. if androstenone gives an extra sex vibe, I’m sure I can put up with alittle bitchiness=) Then again things like too much -nols or comfort mones may have a happy or relaxing vibe.. yet at the same time they can also give a “weakness” and “my P**sy hurts” vibe when used in excess. Well I should know, because I like to OD when I first get any new pheremone.