Human Chorionic Gonadotropin, or hCG, is a hormone produced by the placenta shortly after implantation occurs in a pregnancy. Since hCG can be found in the circulatory system and is excreted with urine, it makes an excellent marker for early detection of pregnancy. After the implantation hCG, levels double almost every 36-40 hours. Because of this, a test capable of detecting very low levels of HCG can confirm pregnancy within 6-7 days of implantation. The Biomerica EZ-HCG test is a one-step immunoassay for the rapid, qualitative determination of human chorionic gonadotropin (hCG) in urine, for the early detection of pregnancy. Twenty-five test cassettes are provided in each professional pack.