Desogestrel

What Does Desogestrel Do?

Desogestrel is a progestogen-only contraceptive pill (also known as the mini-pill) that prevents pregnancy by inhibiting ovulation, thickening cervical mucus, and altering the lining of the uterus. 

How Does Desogestrel Work? (the complicated stuff!)

Desogestrel acts as a progestin in hormonal contraception, primarily preventing pregnancy. It inhibits ovulation by suppressing the hypothalamic-pituitary-gonadal axis. By decreasing gonadotropin-releasing hormone (GnRH) release from the hypothalamus, it subsequently lowers luteinising hormone (LH) and follicle-stimulating hormone (FSH) levels from the pituitary gland. This reduction hinders the growth and maturation of ovarian follicles, effectively preventing ovulation. Additionally, desogestrel may alter cervical mucus and the endometrial lining, further contributing to its contraceptive effectiveness.

Drug Type and Category of Desogestrel

Desogestrel is a hormonal contraceptive that falls under the category of combined oral contraceptives. 

What dosage of Desogestrel should you be taking?

Desogestrel is a progestogen-only contraceptive pill commonly taken at a dosage of 75 micrograms daily. It's important to take the pill at the same time each day, starting on day 1 of your menstrual cycle and continuing without interruption. If you start the pill more than five days after the beginning of your period, you should use additional contraception, such as condoms, for the first two days of pill use. If you miss a pill and it's been more than 12 hours since your usual intake time, take the missed pill as soon as you remember and continue with the next pill at the regular time. In such cases, use extra contraception for the next two days. ¹

For combined oral contraceptives containing desogestrel and ethinylestradiol, the typical regimen involves taking one active tablet daily for 21 days, followed by a 7-day break during which withdrawal bleeding occurs. It's crucial to follow the specific instructions provided with your medication, as formulations can vary. ²

What are the side-effects of Desogestrel?

Common side effects of desogestrel may include nausea, headaches, breast tenderness, and changes in menstrual bleeding patterns. Some users may experience mood changes, weight gain, or an increased risk of thromboembolic events. Additionally, skin reactions or migraine exacerbation could occur. Serious side effects may involve symptoms of a blood clot, such as sudden leg pain or shortness of breath. 

Interactions

Desogestrel, a progestogen used in various contraceptive formulations, can interact with certain medications, potentially affecting its efficacy and safety. Notably, drugs that induce liver enzymes, particularly cytochrome P450 enzymes like CYP3A4, can increase the metabolism of desogestrel, leading to reduced contraceptive effectiveness. Examples of such enzyme-inducing drugs include:

• Antiepileptic drugs:
• Carbamazepine
• Phenytoin
• Phenobarbital
• Primidone
• Topiramate
• Oxcarbazepine
• Antituberculosis drugs:
• Rifampicin
• Rifabutin
• Antiretroviral drugs:
• Efavirenz
• Nevirapine
• Herbal supplements:
• St. John's Wort

Concomitant use of these medications with desogestrel may necessitate additional contraceptive measures, such as using barrier methods during treatment and for a specified period afterward.

Additionally, certain medications can increase the levels of desogestrel in the body by inhibiting its metabolism, potentially leading to an increased risk of side effects. Examples include:

• Antifungal agents:
• Itraconazole
• Ketoconazole
• Macrolide antibiotics:
• Clarithromycin
• Erythromycin
• Certain antidepressants:
• Fluoxetine
• Fluvoxamine

Grapefruit juice can also inhibit the metabolism of desogestrel, leading to increased blood levels and a higher risk of side effects. It's advisable to avoid consuming grapefruit or its juice while taking desogestrel-containing contraceptives.

Desogestrel may also interact with certain laboratory tests, potentially causing false results.

Natural Alternatives to Desogestrel

Barrier Methods: Natural barrier methods, such as condoms or diaphragms, can be used without hormonal intervention. These methods also provide protection against sexually transmitted infections ³ This is one of the best non-medication methods for preventing pregnancy and is our recommendation. Despite the functional applications of getting condoms on, they remain a much better alternative to drug-use due to not having side-effects. 

Natural Family Planning (NFP): NFP involves tracking ovulation through methods like basal body temperature, cervical mucus observation, or calendar-based systems ³. This approach requires diligence and accurate record-keeping but can be effective when used consistently ⁴. However, it can be hard to maintain and there is a degree of inaccuracy that may be risky for many. 

Herbal Remedies: Some herbs are traditionally used to regulate menstrual cycles and may help in contraception. Examples include wild yam and neem?2;. However, their efficacy and safety are less studied compared to conventional contraceptives ⁵. This is not a reliable method of preventing pregnancy. 

Abstinence or Fertility Awareness: Abstinence during fertile windows, identified using fertility awareness methods, is a natural and hormone-free contraceptive choice ³. This may not be reliable but depends on the use of abstinence. 

Lactational Amenorrhea Method (LAM): This method relies on exclusive breastfeeding, which can suppress ovulation naturally for up to six months postpartum ³. This is not a guaranteed method of preventing pregnancy. 

Copper Intrauterine Device (IUD): While not entirely "natural," a copper IUD is hormone-free and utilises copper's spermicidal effects. It is long-acting and reversible ³. 

Interesting facts about Desogestrel

Desogestrel, commonly known as a progestogen-only contraceptive pill or "mini-pill," offers a reliable and hormone-specific alternative to combined oral contraceptives as it contains no estrogen. It is particularly effective in preventing pregnancy by consistently inhibiting ovulation and thickening cervical mucus, creating a robust barrier against sperm penetration. Unlike many other progestogen-only pills that require strict timing, Desogestrel provides flexibility with up to a 12-hour window for daily intake without compromising its efficacy. It is also an excellent option for breastfeeding mothers, as it does not affect milk production and has minimal transfer to breast milk. 

Disclaimer

This article is generated for informational purposes only. It was created in January 2025. Medications and medical guidance can change over time. Therefore, it is essential to consult with your general practitioner or healthcare provider before making any decisions regarding medications or treatment plans. Your GP can provide personalised advice based on your specific health needs and conditions.

References

1. https://www.nhs.uk/contraception/methods-of-contraception/progestogen-only-pill/how-to-take-it/?utm_source=chatgpt.com
2. https://bnf.nice.org.uk/drugs/ethinylestradiol-with-desogestrel/?utm_source=chatgpt.com
3. World Health Organization (WHO). "Natural Family Planning: Methods and Effectiveness." https://www.who.int/ 
4. American College of Obstetricians and Gynecologists (ACOG). "Fertility Awareness-Based Methods of Family Planning." https://www.acog.org/ 
5. Office of Dietary Supplements, National Institutes of Health (NIH). "Herbal Products and Safety." https://ods.od.nih.gov/