The first product of Geek & Gorgeous I tried out is the 101 C-Glow 15% Vitamin C Serum, made fresh every week (which also means it might be out of stock). They recommend keeping the serum in the fridge (which I forgot to do in the beginning) to keep it fresh up to 3 months instead of 6 weeks. Now, normally products that come with the fridge suggestion immediately turn me off, however, I am willing to make an exception for a minimal-INCI vitamin C serum. Especially that the formula is preserved, so there is no immediate worry about growing pathogens. My serum was at room temperature for about a month and the only change I saw was a slight oxidation from a completely transparent (well done!) serum to the slight yellow tone.
Now for my personal experience with the product. My skin is very sensitive to L-AA, I know that my limit is about 10%. My skin took to the serum very well in the beginning, but after using it every morning for about 3 weeks, I started to notice irritation in the usual place – at the tops of my cheekbones. Obviously, I can just drop less of the serum into an essence or another serum to lower the L-AA concentration, also raising the pH and lowering the irritation but it’s not my favorite way to use a vitamin C serum. Another thing that keeps me from replacing my current favorite vitamin C (that costs 4-5 times as much) with this one is the very very light texture of this – I have grown to like my serums to be at least also a bit more emollient besides their first function. As you understand, the super light texture will be a huge bonus for someone else. So, as always, the choice is yours.
I recommend taking a look at their range of products, the choice of active ingredients is slightly different from other things out there.