Vitamin C serum + Shelf life?

[troubled skin]

Hi Sarah and all

First I would like to take this time to thank you for your website full of valuable information and wonderful products, really appreciate this important information especially regarding my situation (pigmentation scars and indented acne scarring) This is my first post I am sure I will be posting many more threads for help. Understanding that vitamin C is essential for collagen synthesis and especially effective when applied topically in serum form. Vit.C serums are costly and would be interested in making my own homemade serum, as recommended on the site. I have purchased Vit.C crystals including the serum bottle aswell as the dermaroller ect...from your online store. My question first is regarding potency, I have been using serums for some time and would like to make 10-15% potency could you maybe give some measurements to achieve this?. Second question is regarding shelf life how long can the L-Ascorbic acid in crystal form last before it decreases in effectiveness? and in reference to the prepared serum what life-time does this have aswell as placing it in the fridge would this prolong it's quality. Thankyou

[SarahVaughter]

I just added this to our user guidelines:

• L-Ascorbic     acid in crystal form is very stable when kept cool, dark, dry and     airtight. It can thus be stored for at least a year without     significant degradation. Vit. C solution keeps a month when kept     airtight in the fridge.

If you want to make a 10% solution, you need to use ten grams of vit. C per 90 ml of water.

You could dissolve a flattened tablespoon of vit. C in nine tablespoons of water to get 10% strength. 15% strength would be achieved when using only six tablespoons of water.

[troubled skin]

Thankyou Sarah appreciate it.