Can estrogen help suppress fsh?

Yes: In a simplified way, the higher the fsh is, the more the body is 'calling out' for estrogen. This makes it a type of reverse test: a high fsh means low estrogen and a low fsh means enough estrogen. If we are trying to prove a woman is going through menopause, we may check an fsh & see if it is very high confirming menopause. If she is on estrogen we might be fooled as her fsh could be then normal.

Why: Why do you want to suppress fsh. Estrogen will suppress lh, who's job it is to stimulate estrogen in the first place. Fsh relates to egg production, not estrogen.