Ключевые слова: 3d, atom, atomic, birth, c20h26o2, carbon, chemical, chemistry, composition, compound, contraceptive, disease, drawing, drug, flat, formula, generic, hormonal contraceptive, hormone, hydrogen, icon, line, medicinal, medicine, menopausal, menopause, model, molecular, molecule, norethindrone, norethisterone, oral, oxygen, painful, period, pharma, pharmaceutical, pharmacology, pharmacy, premenstrual, progestin, progestogen, skeletal, structure, therapy, treatment,