An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body.Such reactions are called allergies.hen an allergen enters the body of an individual that is predisposed to allergies, it triggers an immune reaction and the production of antibodies. These allergen antibodies migrate to mast cells lining the nose, eyes and lungs.
Progestins are synthetic progestogens, medications that have effects similar to those of progesterone. The two most common uses of progestins are for hormonal contraception (either alone or with an estrogen), and to prevent endometrial hyperplasia from unopposed estrogen in hormone replacement therapy.
Posted on March 17, 2012 by. Progesterone is a hormone produced primarily in womenâs bodies, which helps regulate the menstrual cycle. Although its best known function is to help regulate the menstrual cycle, it has many more uses, which will be discussed in another article.hroughout all this, progesterone does not work alone. Several other important hormones are involved. In the Follicular State (days 1 to 14 of the cycle), one of these important hormones is follicle-stimulating hormone (FSH), which is secreted from the pituitary gland.