I am planning to try these two together for focus and memory:
http://www.vitacost.com/vitacost-pho...ng-60-softgels
http://www.vitacost.com/vitacost-l-t...mg-60-capsules
Omega-3 is supposed to be helpful also, and anyway is good for all-around health (basically fish oil). Don't be fooled into thinking "complete" Omega combos are good. The American diet is way out of balance; more omega-3 is needed to balance the over-abundance of omega-6 we get in our diets. Here's an article that explains this better than I can:
http://www.fitday.com/fitness-articl...ference.html#b
and I may try this one at night to help with sleep, as I tend to wake at night:
http://www.vitacost.com/vitacost-gab...g-100-capsules
Regarding collagen, I am not aware of any supplement that helps with that. Typically you need to use topical creams (such as retinol) or therapies such as micro-dermabrasian. These stimulate the skin to produce more collagen.
Most medical doctors know very little about supplements. They just follow FDA guidelines.