I'm a biochemist, and I think it's completely useless in cosmetics or food supplements. It's a protein that normally is in many human tissues, including skin. But it cannot be transfered into the skin without a needle (so it will remain onto the suface). And if you eat collagen, it simply digests as any other protein, like those from meat or other food. Cosmetic companies, unlike farmaceutical, generally don't need any strong proof about positive effects. So they think: "There is collagen in skin normally, let's smear skin with some more collagen. It won't cause any harm." P.S. If it helped you, could you correct my grammatical mistakes here:)

Sometimes it's ok to say or write "я имею". For example: У меня есть право = Я имею право = I have a right У меня есть возможность = Я имею возможность = I have a possibility there's also a phrase where you cannot use "У меня есть": Я имею в виду = I mean

So, you already know about meaning of "такой" :) Some remarks: it can be used with nouns (такой дом), adjectives (такой большой), but you should use "так" with adverbs. "He is running so fast"=="Он так быстро бежит"=="Он бежит так быстро".