arm posterior to the groove between the biceps and triceps muscles. The average time for insertion is 0.5 to 1 minute. A bandage should be kept on the insertion site for 24 hours afterwards. Bruising and mild discomfort are common after insertion. Serious insertion site complications such as infection can occur very rarely, in less than 1% of patients. If a woman receives an implant outside the first five days of her period, she should wait to have sex or use a backup method of contraception (such as a condom, female condom, diaphragm, sponge, or emergency contraception) for the following week after insertion to prevent pregnancy. However, if the implant is inserted during the first five days of a woman's period, she is protected for that cycle and beyond. Implants can be removed at any time if pregnancy is desired. The rod must also be removed by an experienced clinician. At removal, a local anesthetic is again used around the implant area at the distal end. If the provider cannot feel the implant, imaging tests may be necessary to locate the rod before it can be removed. A small incision is made in the skin over the end of the implant site. In some cases, a fibrous sheath may have formed around the implant, in which case the sheath must be incised. The implant is removed using forceps. The removal procedure lasts, on average, 3 to 3.5 minutes. Fertility after removal Within a week of removal, the hormones from the device leave the body and etonogestrel is undetectable in most users. Most women will begin to ovulate within six weeks of removal. Fertility levels will return to what they were before implant insertion. Differences Nexplanon and Implanon NXT are essentially identical to Implanon except Nexplanon and Implanon NXT have 15 mg of barium sulphate added to the core, so it is detectable by x-ray. Nexplanon and Implanon NXT also has a pre-loaded applicator for easier insertion. Pharmacology The mechanism of action of progestin-only contraceptives depends on the progestin activity and dose. Intermediate dose progestin-only contraceptives like Nexplanon or Implanon allow some follicular development but inhibit ovulation in almost all cycles as the primary mechanism of action. Ovulation was not observed in studies of Implanon in the first two years of use and only rarely in the third year with no pregnancies. A secondary mechanism of action is the progestogenic increase