Birth Control Patch. The Birth Control Patch is a very thin patch self adhesive patch that is applied directly to a woman’s skin. The hormones(estrogen and progesterone)are absorbed through the skin(transdermally) at a controlled and constant rate while the patch is being worn. Each Patch is worn contains enough hormone to be effective for seven days for a woman of average weight. The patch is not recommended for women over 198 pounds. The patch must be changed every week for three weeks. The forth week of every cycle is a “patch free” week. When the third patch is removed it is not replaced. Most women will get a period during this “patch free” week. At the end of the “patch free” week a new cycle begins and a new patch is applied. The advantage to the patch for many women is that it requires a bit less attention than a daily pill. Some women may experience an allergic reaction to the adhesive on the patch. This and contraindications to estrogen use are reasons for women to avoid the patch as a Birth Control Method. Risk, Benefit and side effect profiles for the patch are similar to those of Combined Oral Contraceptive Pills as they contain the same types of hormones.