Hi, Duoluton and Novelon are both combination oral contraceptive pills that contain estrogen and progestin hormones. They work by preventing ovulation and thickening the cervical mucus, making it difficult for sperm to reach the uterus. Weight gain and nausea are potential side effects of hormonal contraceptive pills, including Duoluton and Novelon. While weight gain may be a concern for some individuals, it is important to note that not everyone will experience this side effect, and it may vary based on factors such as diet and exercise habits. Nausea is also a common side effect of hormonal contraceptive pills, especially when starting a new pill or during the first few months of use. However, if the nausea is severe or persistent, it may be a sign of a more serious issue and should be discussed with your healthcare provider. As for the length of time you should take the pill, your healthcare provider will make a recommendation based on your individual health needs and medical history. In general, combination oral contraceptive pills can be safely taken for long durations as long as they are monitored by a healthcare provider. It is important to note that hormonal contraceptive pills do not protect against sexually transmitted infections and should not be used as the sole method of contraception in high-risk situations. Additionally, if you experience any concerning symptoms while taking the pill, such as severe abdominal pain or chest pain, you should seek medical attention immediately. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Priyanka, General & Family Physician