The pharmaceutical company does not list weight gain as a possible side effect of Yasmin on the contraceptive pill's Web site. The website Drugs, however, does list changes in weight or appetite as a possible side effect. The Mayo Clinic states that if birth control pills do cause weight gain, the effect is mild. Some women may retain more fluid when taking birth control pills, so it may seem as if they've gained weight.
Decide if the weight gain is significant enough to try another pill. If you are still in a normal weight range with a healthy body mass index, or BMI, you may want to continue taking the pill if it's not causing any other problems. If weight gain is significant and you are now in an unhealthy weight range, ask your doctor about other birth control pills with less risk of weight gain.
Make sure the weight you've gained isn't water weight. If you're retaining water, limit your sodium intake. Consider taking calcium or magnesium supplements, which may reduce water retention, according to the Mayo Clinic.
Ask your doctor about diuretics if you're retaining water. Your doctor may also recommend a vitamin supplement if you choose to take diuretics, because they can reduce potassium.
Exercise regularly to help you burn calories and get rid of excess water weight.
Make small dietary changes if you decide to continue taking Yasmin and if the weight you've gained is not water weight. Try to fill up on low-calorie foods if Yasmin increases your appetite. Foods with high water- and fiber-content tend to promote satiety. Eat more fruits and vegetables.
Substitute low-calorie foods for high-calorie items. If Yasmin is boosting your appetite, you can eat more if you choose lower-calorie items: Try chicken instead of beef; use salsa as a condiment instead of cheese or sour cream; or snack on popcorn instead of chips.
Consume frequent, small meals if Yasmin increases your appetite. Small meals help regulate your blood sugar and keep you from getting too hungry and overeating.
Work with a dietitian who can help you develop a weight loss plan. Together, figure out how many calories you typically consume each day, then make a goal to reduce that number. A dietitian can help you determine if any food choices you're making are sabotaging your goals.