
Originally Posted by
Phate
In short, your body has feedback loops and specialized cells that sense levels of different hormones and enzymes in the blood, when these get out of balance your body tries to correct it
estrogen rebound(for us) normally happens after using a compound letrozole (that reduces estrogen levels by 99%), after the drug leaves the body the feedback loop realizes that there is very little estrogen left so it starts producing a ton of estrogen to bring the body back to homeostasis(balance) and in the process causes a huge flux of estrogen called estrogen rebound