Desogestrel is a third-generation progestin used primarily in hormonal contraception and hormone replacement therapy. It is a prodrug that is rapidly metabolized in the liver to its active metabolite, Acofide 100mg (http://pharmacie-ruthen-pharma.com) etonogestrel. Developed to reduce the androgenic side effects associated with earlier progestins, desogestrel exhibits high progestogenic activity and minimal androgenic activity, making it a preferred choice for many women.

Chemistry and Pharmacokinetics

Chemically, desogestrel is a derivative of 19-nortestosterone. It is almost completely absorbed after oral administration with a bioavailability of about 76%. Peak plasma concentrations are reached within 1–1.5 hours. It is extensively bound to albumin and sex hormone-binding globulin (SHBG). The elimination half-life of etonogestrel is approximately 30 hours, allowing once-daily dosing. Metabolism occurs via hydroxylation and conjugation, and metabolites are excreted primarily in urine and feces.

Mechanism of Action

Desogestrel acts primarily by inhibiting ovulation through suppression of gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) surge. It also thickens cervical mucus, impeding sperm penetration, and alters endometrial lining to reduce implantation likelihood. Unlike earlier progestins, desogestrel has negligible androgenic effects due to its high relative binding affinity for progesterone receptors and low affinity for androgen receptors.

Clinical Uses

  1. Combined Oral Contraceptives (COCs): Desogestrel is commonly combined with ethinylestradiol in monophasic or triphasic pill formulations. These are highly effective for contraception with a Pearl Index of 0.1–0.9. Additional benefits include regulation of menstrual cycles, reduction in dysmenorrhea and menorrhagia, and decreased risk of ovarian and endometrial cancers.
  2. Progestin-Only Pill (POP): Desogestrel is also available as a 75 µg daily pill (Cerazette® and generics). This is a popular choice for breastfeeding women or those with contraindications to estrogen. It inhibits ovulation in about 97% of cycles and is effective with typical use failure rates similar to COCs.
  3. Hormone Replacement Therapy (HRT): In postmenopausal women, desogestrel combined with estrogen is used to protect the endometrium and reduce vasomotor symptoms.
  4. Other Uses: Off-label uses include treatment of endometriosis, menstrual migraine, and acne. Some studies suggest benefit in polycystic ovary syndrome (PCOS) although not FDA approved.

Efficacy and User Satisfaction

Clinical trials demonstrate high contraceptive efficacy. With perfect use, failure rate is <0.1% for COCs and about 0.3% for desogestrel POP. Typical use rates are under 3% per year. User satisfaction is generally high due to favorable side effect profile, though some women discontinue due to irregular bleeding.

Side Effects and Safety

Common side effects include headache, nausea, breast tenderness, mood changes, and weight changes. Breakthrough bleeding is common with the POP, especially in the first few months. Venous thromboembolism (VTE) risk is lower than with fourth-generation progestins but slightly higher than with levonorgestrel-containing pills. Absolute risk remains low (about 1–2 per 10,000 woman-years). Desogestrel is contraindicated in women with history of VTE, known thrombophilic disorders, severe liver disease, or hormone-sensitive cancers. It may slightly increase risk of breast cancer with long-term use, but the risk is small and comparable to other hormonal contraceptives.

Drug Interactions

Liver enzyme-inducing drugs (e.g., rifampicin, barbiturates, carbamazepine, St. John’s wort) reduce desogestrel efficacy and may require additional contraceptive methods. Antibiotics not affecting liver enzymes generally have no significant interaction.

Comparison with Other Progestins

Compared to first-generation (norethisterone) and second-generation (levonorgestrel) progestins, desogestrel causes less acne, hirsutism, and lipoprotein changes. It has a favorable lipid profile, slightly increasing HDL cholesterol. It is less androgenic than levonorgestrel but has similar efficacy.

Special Populations

  • Adolescents: Safe and effective, with benefit of cycle regularity.
  • Perimenopausal women: Can be used in low-dose COC or POP; no upper age limit if no contraindications.
  • Breastfeeding: Desogestrel POP is considered safe and does not affect milk supply.
  • Overweight/Obese: Efficacy may be slightly reduced but still acceptable; no dose adjustment needed.

Conclusion

Desogestrel is a well-tolerated, effective progestin widely used in contraception and HRT. Its minimal androgenic side effects make it a popular choice for women seeking reliable hormonal contraception with good cycle control. While risk of VTE is slightly higher than with some older progestins, it remains low. As with any hormonal medication, individual risk assessment and patient counseling are essential for safe use. Ongoing research continues to explore its potential in other gynecological disorders.