Annyeong, Everyone~ Fasting month/Ramadhan is coming to an end soon omg! I feel like this year is the fastest Ramadhan month that I am going through. Time. Flies. So. Fast. Do you guys remember the popular OST C20 Vitamin C serum ? If you never heard of it before you can check out my existing review on the product by clicking on the link below: OST Original Pure Vitamin C20 Serum Review I loved that product, I considered it as my HOLY GRAIL and I am happy to be able to use it again this year! This Tiam My Signature C-Source is the renewed version of the OST Original Pure Vitamin C20 Serum . This is because the brand OST C20 is rebranded to TIAM . As for the product, ONLY the product name has been changed while the ingredients and everything else stayed the same. Disclaimer : I received this product from TIAM in exchange for my honest review. Texts on the box still looks the same except for the name. Same old ingredients~ Water, Asc...