Understanding L-Ascorbic Acid (Vitamin C) Issues

L-Ascorbic Acid, a form of Vitamin C, is a potent ingredient in skincare, but it is also known for its instability, particularly when exposed to water, air, light, and heat. This instability can lead to degradation, affecting its appearance, smell, and effectiveness.

Here's an explanation for the issues you've encountered:

• Sediment that doesn't dissolve: L-Ascorbic Acid is highly prone to oxidation when dissolved in water. When it oxidizes, it breaks down into other compounds that are insoluble and no longer provide the benefits of Vitamin C. If the sediment from your old bottle dried out, it likely means the Vitamin C had already oxidized and degraded. These degraded products will not redissolve, even with shaking or refrigeration.

• Different smell in a new batch: While slight variations can occur between batches of raw ingredients, a noticeable or unpleasant change in smell can sometimes indicate that the product has started to degrade. L-Ascorbic Acid powder should ideally be a pure white powder with minimal to no odor. Any significant smell, especially a metallic or off odor, could be a sign of oxidation.

• Reduced effectiveness or skin feeling less plump: The effectiveness of L-Ascorbic Acid is directly related to its stability. If the product has degraded due to improper storage or exposure to environmental factors, its concentration of active Vitamin C decreases, leading to reduced benefits. While skin can adapt to products over time, a significant drop in perceived effectiveness, especially when using a new batch or a larger quantity stored for longer, is often due to the ingredient's degradation rather than skin tolerance. Proper storage in a cool, dark place, tightly sealed, is crucial for maintaining its potency.

To ensure the best results from L-Ascorbic Acid, always store it properly, minimize exposure to air and moisture, and use it within its recommended shelf life, especially after opening.