Can Zuguang Powder still be used after its expiration date?

Generally, it is not recommended to use Zuguang Powder after its expiration date, even if there are no visible abnormalities, as hidden risks may still exist. If in doubt, it is advisable to consult a healthcare professional in advance. Detailed explanations are as follows:

Zuguang Powder contains active ingredients such as salicylic acid and benzoic acid. After expiration, the potency of these components gradually diminishes, making the product ineffective against fungal infections. Using expired powder may delay treatment for conditions like athlete's foot or tinea manuum/pedis, potentially worsening symptoms. Particularly for persistent fungal infections, ineffective medication fails to suppress fungal growth and may even promote drug resistance.

Expired Zuguang Powder may pose safety risks due to chemical changes in its composition. On one hand, the medication may absorb moisture, clump together, or generate irritating substances due to altered chemical properties, which can lead to skin reactions such as redness, itching, or stinging upon contact. On the other hand, improper storage may cause bacterial contamination in expired products, increasing the risk of skin infection when used. Even if the product appears normal externally, internal compositional changes cannot be detected by the naked eye; therefore, using it is not advised.

When dealing with conditions like tinea pedis or tinea manuum, always purchase medication within its expiration period and follow the instructions carefully. Discontinue use immediately and seek medical advice if any skin discomfort occurs.