HCG 5000IU is a glycoprotein hormone produced normally by the placenta during pregnancy. The HCG molecule consists of two different subunits (± – and І-subunits) linked together. The I-subunit, with a molecular weight of about 30,000 daltons, imparts biological and immunological specificity to the entire HCG molecule due to its unique amino acid composition and amino acid sequence. The ± subunit, with a molecular weight of about 18,000 daltons, is essentially identical to the ± subunits of the pituitary glycoprotein hormones: luteinizing hormone (LH), follicle-stimulating hormone (FSH) and thyroid-stimulating hormone (TSH).
Produced by the placenta HCG 5000IU, in its function similar to the LH of the pituitary (due to the ± subunit), prevents autolysis of the corpus luteum and induces it to secrete large amounts of progesterone, which contributes to the preservation of pregnancy. In the serum of pregnant women, one week after conception, the HCG concentration rises to 5–50 mIU / ml and continues to increase exponentially during the first 10 weeks of pregnancy, reaching a maximum of 100,000–200000 mIU / ml by the end of the first trimester. The appearance of HCG in the urine or serum soon after conception and the rapid increase in its concentration make HCG an ideal indicator for determining and confirming pregnancy.