Yes tea bags do help to get rid of and reduce dark circles under the eyes.
To use tea bags for dark circles heat up some water and dip the tea bags into the hot water for 5 minutes or so to get them hot enough to apply to your eyes.
Then you can also have a cup of tea as well with the tea made from the tea bags being warmed up.
After the tea bags are warmed up you can place them on your eyes and lay back and relax until the tea bags cool down which is around 10 to 20 minutes.
It can take a few days to a few weeks of applying the tea bags to your eyes to see significant results and see the dark circles under the eyes disappear but they do work.
You can also apply a cool cucumber slice to each eye and lay there for 30 minutes or so.
Or use some dark circle remover cream that you can get online or over the counter.