A good home remedy that works for removing spots on your forehead and even acne is to take a lemon and squeeze the lemon juice out of the lemon onto a cotton ball.
Then apply the lemon juice to the spots on your forehead and leave the lemon juice on the spots for 10 minutes.
You may have to repeat the above procedure with the lemon juice and cotton ball for up to a week to see full results and see the spots go away on your forehead but the lemon juice will work to remove the spots and acne from your forehead and even face.