Yes AIs are always necessary on any test or test + whatever(& w/19nors as Tren and Nandrolone both are progestins) which raise prolactin and can cause serious sides(hence a DA like caber or Prami in addition to AI - or on hand til you pull your mid cycle bloods and make adjustments) if you can control your estro in a successful manner than prolac will be much easier to control or keep controlled...