Iron defficiency and fixing it

sorry maybe this isn't the right sub, but i found nowhere to post this.

i always had dark circles around my eyes and pale skin, always exhausted, i recently found out it's because of my iron defficiency ( probably because of my green tea abuse),i'm now taking iron pills

is there anyone who had same issue and fixed it ? did you notice any improvements in your cognition and overall energy levels? and how long did it take for you to notice change ? i just started taking these pills