Can I bring omega 3 pills 10 boxes/100pills in each box?

Daniem, the customs require that all passengers can bring things for personal use and within reasonable quantity. How long are you planning to stay in China? If you just stay for a few days, then I am afraid that you may not bring so many boxes.

However, the customs doesn't check everyone's luggage. If you are lucky, you won't have the problem when you pass the customs as long as you put them in your checked luggage.