To get the effects of great hair and skin, it’s less about increasing your daily dosage and more about consistency and sticking to it.
When our founder, Sally, got burned, she took 10g of collagen twice a day (so in total 20g). Although we can't speak for all, the only thing that happened to her was better skin and better hair!
Recommended dosage varies per person, age, and his or her body type in addition to the health of their kidneys (too much protein can be hard on weaker kidneys).
Collagen is also more effective the more bioavailable it is (marine collagen is more bioavailable than bovine collagen), so lesser amount of marine collagen can be more effective than bovine collagen.
Of course, going overboard with anything can be harmful— even drinking too much water can be harmful for you!— so I recommend that those starting to take collagen ease into the routine (so take 5g for a few days first, and then 10g, and then cap it at 30g).
There’s only so much your body can do with the extra amounts of protein, especially because our bodies cannot store it day to day.