Triple C is a collaboration between Charlotte Cho, one of the co-founders of Soko Glam, and COSRX. When it was first introduced, the hype around it was so strong that it sold out within hours upon its release! It remains an extremely popular product, with good reason.
I found these serums on Amazon, as I hastily scrolled about trying to find replacements for my dwindling retinol and vitamin C. I liked that the Mad Hippie products had a fairly short ingredients list, and the pricing was about average for 30ml size bottles of product. Only one of these serums, however, has truly impressed me.