Hi, This is Dr. Nikhil Patil, I am a Homeopathic Consultant.                                Most important thing - loosing weight only with the help of Medicines is not good for you at this age. Medicines will only accelerate the process of loosing weight but you need to have exercise and eat healthy and on time to have ideal weight.                  There are so many reasons because of which one can gain weight. What you have said about having no time for exercise and staying in hostel that can tell us one thing and that is you may be having sedentary lifestyle. Along with that there are some hormone related problems like PCOS - Polycystic Ovarian Syndrome, Hypothyroidism which can cause rapid weight gain in females. Some eating disorders are also responsible for weight gain. Not eating on time, junk food and lack of sleep also contribute to weight gain.                  You need to dedicate some time for yourself and start walking in the morning. Eat healthy and on time. If you have anymore questions regarding this feel free to communicate. Thank You. Have a nice day ahead.