Tren and behavioural changes, infidelity

Is it really the Tren?

My boyfriend (27M) cheated on me for a long time (once every 2 mths). I would always find out and he would initiate a breakup, and id always say no and forgive him, it got to the point where i stayed with him while he talked to another girl.

Recently I started fading away, and he stopped tren (both unrelated) and he suddenly been showering me with love unlike any other time. I cant tell if its his narcisstic personality where hes trying to draw me back to him (that unhealthy cycle of dating a narcissist), or that he's really a different person off Tren.

Does anyone know if its really the Tren? Anyone who has used Tren or dated someone on Tren, please help...