Alca
Berminyak/Tidak Sensitif
I tell mostly by color because the smell can be misleading. On the other hand, some brands color their vitamin C serums orange, so you can't tell. ๐
Here is a picture of my vitamin c creme from a tube I didn't use for some time. The orange color means it's completely oxidised. As it goes to the right, it's less oxidised.
17
0
Betweendots
Berminyak/Sensitif
There are some tricks
1. Choose right version of vitamin C - ascorbic acid is a basic version, but very unstable. 3-O-Ethyl Ascorbic Acid is probably the most stable, but also most expensive vitamin C deriverate. MAP and SAP are used by many brands instead of Ascorbic Acid
2. Keep the product away from light and temperature - keep it in a fridge.
3. Use products with Vitamin C and Vit E + Ferulic Acid or Niacinamide. Ferulic Acid makes Vitamin C survive bit longer.
8
0
syahnidaareo
Kering/Sensitif
The color of the product is yellow-orange. Then when applied to the skin, it triggers irritation
3
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Jeannie88
Kering/Sensitif
Depending on brands but if it starts out as โwhiteโ or clear and changes colour to light yellow, it has oxidised.
1
0