Have you heard of the Derma E skincare line? It is sold in Whole Foods and larger health food stores in the US, and the products I've tried from them are quite impressive (and affordable). Are you still in Germany? I don't know offhand if this line is sold there, they are currently not listed on the international distributer list:
I am 29, and have been using a retinol product off and on for the past three years for preventative reasons (but more to clear up acne and even out my skintone, which tends to be blotchy) at night. I have tried the Ester C Moisturizing Serum with E Skin Recovery Complex and the Ester C Moisturizing Creme. I like both of them, but prefer the serum slightly because the creme can get a bit heavy when the weather is warmer. They have other creams that feature retinol as well.
Their website is pretty thorough, and you can get a good idea of what they offer, the benefits of their products, and an ingredient listing.
I tried the line initially through their sample package offer. You get a very generous package of samples (about 12 packets) for just the price of shipping. Here is the link for that:
The "less natural" option that I am using now is Neutrogena's Healthy Skin Anti-Wrinkle Cream, which I have also had good results with, but I wish it didn't have some of the ingredients in it that it does (parabens being the worst). However, this is much easier to find in drugstores for me.
Sorry for the book, but I hope I've helped some