When using night creams regularly, especially products containing lanolin or collagen, potential side effects to consider may include skin irritation, allergic reactions, clogged pores leading to breakouts, or increased sensitivity to sunlight. It is important to perform a patch test before using any new skincare product and to consult with a dermatologist if you have any concerns about using night creams regularly. Additionally, always follow the instructions provided by the product manufacturer and consider factors like your skin type and any pre-existing skin conditions when incorporating night creams into your skincare routine.