Federal health regulators are reviewing the safety of an implantable contraception device after receiving reports of unusual side effects from patients, including fatigue, depression and weight gain.

The Food and Drug Administration says those problems have not been established in studies of the device and are not listed on the product label. But the agency scheduled a September meeting to consult outside experts about the overall safety of the Essure implant, which is marketed by Bayer.

The coil-like device is implanted in the fallopian tubes, where tissue grows over it and eventually blocks sperm from reaching a woman's eggs. The device was approved by the FDA in 2002.

Regulators said late Wednesday that its review of follow-up studies "found no conclusive evidence" of new or widespread complications with the device.