Final answer:
Melatonin supplements can be taken to help adjust to a new time zone, as they aid in realigning the body's circadian rhythm and mitigating jet lag symptoms.
Step-by-step explanation:
The synthetic hormone that can be administered to help someone adjust to a new time zone is melatonin. Melatonin is a hormone that regulates sleep-wake cycles and is naturally produced by the pineal gland in the brain. Its release is stimulated by darkness and inhibited by light. When traveling across multiple time zones, the body's internal clock becomes out of sync with the new local time, leading to jet lag. Symptoms of jet lag include fatigue, irritability, and insomnia. To mitigate these symptoms and help the body adjust to the new time zone faster, melatonin supplements can be taken. These supplements are especially useful when exposure to natural light-dark cycles is not enough to quickly realign the body's circadian rhythm to the new environment.