This should not happen with proper storage. To prevent oxidation, we have used a high level of tocopherol, a strong antioxidant. We have also selected a glass package which is non-porous and impermeable, meaning it blocks oxygen, moisture and other gases. Glass is chemically inert and does not interact with its contents, so this prevents chemical reactions that could accelerate oxidation. We have six months of accelerated stability results showing that the scent does not change over time.