is there any point in taking collagen capsules?

I have done a lot of research in to anti aging and repairing the damage that pregnancy can do to your body, and i have found some interesting 'supplements' and tips for this kind of thing. However, i would like to know if anyone has actually seen any kind of benefits from taking supplements such as collagen, Gotu Kola, Vitamin E and drinking green tea. Also, does any one have any tried and tested methods for facial anti aging and firming up the loose skin caused by pregnancy, the latter being my main priority.

Thanks :o)