Using expired beauty products comes with significant health risks, warns dermatologist Dr. Sweta Rai. Neglecting the expiry dates of skincare and makeup items can lead to potential hygiene and health hazards due to ingredient degradation and increased risk of infection. Dr. Rai emphasizes that expired products lose their effectiveness and may produce an irritant effect on the skin. She advises against using beauty products that have been left open or exposed to moisture or heat, as they can harbor bacterial or infection risks. Additionally, certain ingredients can become more harmful once they surpass their expiration dates. Proper storage is crucial, as incorrect storage can deactivate products with active ingredients like Vitamin C, while high strength active ingredients like hydroquinone and niacinamide are at risk of deterioration when exposed to heat or light. Dr. Rai suggests keeping beauty items in a cool, dry area to prevent bacterial growth and maintain the strength of the product. She also highlights the importance of using products within their valid shelf life to avoid unpredictable chemical reactions.