5α-Dihydrolevonorgestrel

5α-Dihydrolevonorgestrel is a metabolite of the synthetic progestogen, levonorgestrel. It is formed in the body after the administration of levonorgestrel and has similar progestogenic activity.

Chemistry

5α-Dihydrolevonorgestrel is a steroid and a derivative of progesterone. It is more specifically a derivative of 17α-ethynyltestosterone, or norgestrel, with an ethinyl group at the C17α position, a methyl group at the C13 position, and a vinyl group at the C11 position.

Pharmacology

5α-Dihydrolevonorgestrel is a potent progestogen, or an agonist of the progesterone receptor. It has about 150% of the affinity of progesterone for the progesterone receptor. In addition, 5α-dihydrolevonorgestrel has no androgenic, estrogenic, glucocorticoid, or mineralocorticoid activity.

Pharmacokinetics

After oral administration, levonorgestrel is rapidly and almost completely absorbed. It is then extensively metabolized in the liver by reduction, hydroxylation, and conjugation. The metabolites are excreted in the urine and feces.

Medical uses

5α-Dihydrolevonorgestrel is not used directly in medicine, but its parent compound, levonorgestrel, is widely used in various forms of contraception, including intrauterine devices, contraceptive implants, and emergency contraception.

See also

• Levonorgestrel
• Progestogen
• Progesterone receptor