Sex hormone

Types

In many contexts, the two main classes of sex hormones are androgens and estrogens, of which the most important human derivatives are testosterone and estradiol, respectively. Other contexts will include progestogens as a third class of sex steroids, distinct from androgens and estrogens. Progesterone is the most important and only naturally occurring human progestogen. In general, androgens are considered "male sex hormones", since they have masculinizing effects, while estrogens and progestogens are considered "female sex hormones", since they have feminizing effects, although all types are present in each sex at different levels.

Sex hormones include:

• Progestogens
  • Pregnenolone → Progesterone → Allopregnanedione → Allopregnanolone
  • 17α-Hydroxypregnenolone → 17α-Hydroxyprogesterone
• Androgens
  • Dehydroepiandrosterone → Androstenedione → Androstanedione → Androsterone
  • Androstenediol → Testosterone → Dihydrotestosterone → Androstanediol
• Estrogens
  • 2-Hydroxyestrone ← Estrone → 16α-Hydroxyestrone
  • 2-Hydroxyestradiol ← Estradiol → Estriol → Estetrol

Synthetic sex steroids

There are also many synthetic sex steroids. Synthetic androgens are often referred to as anabolic steroids. Synthetic estrogens and progestins are used in methods of hormonal contraception. Ethinylestradiol is an example of a semi-synthetic estrogen. Specific compounds that have partial agonist activity for steroid receptors may require treatment by a steroid in one cell type, and, therefore, act like natural steroid hormones. These compounds are used in certain medical conditions. Some systemic effects of a particular steroid in the entire organism are only desirable within certain limits.