Avoid storing ascorbic acid in metal containers. Ascorbic acid pills and powders, for instance, sometimes come in boxes or bags. They are fine in their original containers as long as you’re able to keep them sealed. If you have a box of ascorbic acid pills, the pills will be sealed in foil packets. You can just leave them in the foil.
Don’t store ascorbic acid in a bathroom or kitchen due to frequent temperature changes. For long-term storage, find a different spot. If you use ascorbic acid in a place like a bathroom, remember to take it back out afterward. It’s a bit of a hassle, but it helps the ascorbic acid last longer.
Light and oxygen exposure can still cause ascorbic acid to degrade in the refrigerator. Leave the bottle sealed and the door closed as much as possible.
Ascorbic acid is safe to use when it changes color, but it won’t have much of an effect. Oxygen converts the ascorbic acid to another form that your body can’t absorb. In general, ascorbic acid powder lasts the longest. Pills can also last for years, too. Liquid ascorbic acid spoils the fastest and may not last beyond 5 to 6 months. Even with proper storage, ascorbic acid loses its potency over time. It’s best when used right away. Try to use ascorbic acid within a few months after opening it.
Some types of ascorbic acid are mixed in with ingredients like silicone to create a gel that is both long-lasting and easy to rub onto your skin. Remember that ascorbic acid is vitamin C. If you buy vitamin C pills or powder, you are still getting ascorbic acid since they are the same thing.
For example, sodium ascorbate is less acidic than L-ascorbic acid. It’s often used in diet supplements and can be good if pure ascorbic acid upsets your stomach. Calcium ascorbate is a similar option. There are other types, like magnesium ascorbate. You can also buy products with ascorbyl glucosamine, ascorbyl palmitate, and other alternatives.
To ensure serum lasts longer, look for varieties made from something like magnesium or sodium ascorbyl phosphate. It will be less potent than a serum made from 100% L-ascorbic acid, but it will last longer in storage. Avoid serum made with water, since the oxygen in water causes ascorbic acid to break down quicker. Instead, try getting ascorbic acid powder and mixing it with water to create your own serum.
If you happen to get a brand in the wrong type of container, transfer it to your own storage containers. For example, you might keep some old brown bottles on hand for storage. Make sure the container is well-sealed. If it isn’t airtight, then the ascorbic acid will spoil much quicker than usual.
Ascorbic acid loses its potency over time, so it’s better to buy only what you’re able to use within a few months. That way, you can replace it with fresher ascorbic acid in the future. Keep an eye on the expiration date printed on containers. If you don’t plan on using the ascorbic acid every day, you might choose a product with a later expiration date, such as a powder over a liquid.
