Sudofed mucus relief day and night capsules contains paracetamol caffeine and phenylephrine. Both sets of capsules contain Phenylephrine Hydrochloride which reduces swelling in the nasal passages to help increase airflow and make breathing easier through your nose. They also contain paracetamol an analgesic which will help bring down your temperature and ease any aches and pains. The Day capsules also contain 25mg of caffeine to help you power through your busy schedule and fight off tiredness associated with colds and flu. Sudofed Mucus Relief Day & Night Capsules are specially formulated to tackle blocked noses headaches fevers sore throats and all the aches and pains associated with the common cold.