The date of expiration of a hyaluronic acid vitamin C concentrate depends on the manufacturer and the quality of the formulation process. Still, unlike other skincare products whose potency can last several years, vitamin C formulation has a relatively shorter shelf-life that rarely exceeds 12 to 18 months. This is mostly because ascorbic acid, the main active ingredient here, is very prone to oxidation and naturally degrades quickly, especially when exposed needlessly to UV rays. Still, this should be more than enough time for you to maximize its anti-aging benefits. You can, nonetheless, extend the life of your vitamin C formulation by storing it in a cool and dark place away from UV rays, your kitchen fridge is an ideal example of a perfect storage place. Also, remember to reseal the container/bottle properly after use to reduce exposure to the environment.