Marvelon

Marvelon is a combined oral contraceptive (COC) pill containing desogestrel 150 micrograms and ethinylestradiol 30 micrograms. It is a monophasic pill, meaning each active tablet contains the same fixed dose of both hormones throughout the 21-day active pill cycle. Marvelon uses desogestrel, a third-generation progestogen that offers a good tolerability profile and is associated with a relatively low incidence of androgenic side effects such as acne and unwanted hair growth.

Mechanism of Action

Marvelon prevents pregnancy through three complementary mechanisms. First, and most importantly, it suppresses ovulation by inhibiting the hypothalamic-pituitary axis, thereby preventing the LH surge necessary for egg release. Second, it thickens the cervical mucus, making it more difficult for sperm to penetrate and reach an egg. Third, it alters the endometrial lining to make implantation less likely in the unlikely event that ovulation and fertilisation were to occur. When taken correctly (one tablet daily, consistently), Marvelon is over 99% effective at preventing pregnancy.

Why Desogestrel?

Third-generation progestogens such as desogestrel are selectively progestogenic and have minimal androgenic activity compared with older progestogens like levonorgestrel. This means that Marvelon is less likely to cause oily skin, acne, or hirsutism. Women who have experienced these side effects on levonorgestrel-containing pills such as Microgynon sometimes find Marvelon better tolerated. Desogestrel also has a more favourable effect on the lipid profile compared with second-generation progestogens.

Cycle Control and Withdrawal Bleeds

Marvelon is taken over a 21-day cycle followed by a 7-day hormone-free interval, during which a withdrawal bleed (similar to a period but lighter) typically occurs. Withdrawal bleeds on Marvelon are generally regular, predictable, and lighter than natural periods, which many women find beneficial.

Marvelon tablets are taken orally, one per day for 21 consecutive days, followed by a 7-day break during which no tablets are taken. A withdrawal bleed usually occurs during the pill-free week. A new pack is started on the 8th day after the previous pack ended, regardless of whether the withdrawal bleed has finished.

Starting Marvelon

For the best cycle control, Marvelon should ideally be started on the first day of menstruation, in which case it provides immediate contraceptive protection. Starting on days 2 to 5 of the cycle is also acceptable, but additional barrier contraception should be used for the first seven days. If starting after a first-trimester miscarriage or abortion, contraceptive protection begins immediately if started on the same day. After childbirth (without breastfeeding), Marvelon can usually be started three to four weeks postpartum.

Missed Pills

Contraceptive protection may be reduced if a pill is missed or taken more than 12 hours late. If a pill is fewer than 12 hours late, it should be taken as soon as remembered, with the next pill taken at the usual time. If a pill is more than 12 hours late, the rules for missed pills (detailed in the package leaflet) should be followed carefully, and condoms should be used for the following seven days. Missing pills during the first or last week of the packet carries a higher risk of unintended pregnancy, as this may lengthen the hormone-free interval.

Adults and adolescents post-menarche: One tablet daily for 21 days, followed by a 7-day pill-free interval. Begin the next pack immediately after the 7-day break.

Starting day: Day 1 of the cycle (immediate protection). Days 2-5: additional barrier contraception required for 7 days.

Missed pill (fewer than 12 hours late): Take immediately; continue as normal.

Missed pill (more than 12 hours late): Take most recently missed pill immediately; use condoms for next 7 days; follow package leaflet for specific missed-pill guidance based on timing in the cycle.

Switching from another COC: Start Marvelon the day after the last active tablet of the previous pill, without a break.

Switching from a progestogen-only pill: Start on any day; no break needed; use additional contraception for 7 days.

Hepatic impairment: Contraindicated in active liver disease or history of hepatic disease if liver function has not returned to normal.

Common Side Effects

• Headache or migraine
• Nausea, particularly in the first few months
• Breast tenderness or engorgement
• Mood changes and irritability
• Reduced libido
• Breakthrough bleeding or spotting, especially in early cycles
• Weight changes

Serious Side Effects

• Venous thromboembolism (VTE): blood clots in legs or lungs, seek urgent medical help if leg pain, sudden breathlessness, or chest pain develops
• Arterial thrombosis: stroke, heart attack, increased risk in smokers over 35 and those with cardiovascular risk factors
• Severe hypertension: may require discontinuation
• Hepatic adenoma or hepatocellular carcinoma (rare with long-term use)
• Cervical cancer: slightly increased risk with prolonged use (five or more years); regular cervical screening is important

Marvelon carries a small but real risk of venous thromboembolism, which is approximately three to four times higher in COC users than in non-users. The absolute risk remains low -- around 3 to 4 cases per 10,000 women per year -- but is higher than with some other pills and significantly lower than the risk during pregnancy. Women with existing risk factors for blood clots, such as obesity, smoking, a family history of VTE, or thrombophilic conditions, should discuss their contraceptive options carefully with their prescriber.

Smoking and Age

Women who smoke and are over 35 years of age should not use Marvelon or any other combined hormonal contraceptive. Smoking combined with oestrogen substantially increases the risk of serious cardiovascular events. Women under 35 who smoke should be strongly advised to quit and advised of the cardiovascular risks of continuing to smoke while using COCs.

Monitoring and Review

Blood pressure should be measured before starting Marvelon and monitored periodically. COCs should be stopped at least four weeks before planned major surgery with prolonged immobilisation, as the risk of blood clots is increased in this setting. Women who develop migraine with aura while taking Marvelon should stop the pill immediately and seek medical review, as aura migraine increases stroke risk. Regular cervical smear tests and breast examination are advisable for women on long-term COC therapy.

• Current or past venous thromboembolism (DVT or pulmonary embolism)
• Current or past arterial thrombosis (myocardial infarction, stroke, TIA)
• Migraine with aura (significantly increased stroke risk)
• Smoking in women aged 35 or over
• Severe or multiple risk factors for arterial or venous disease
• Active or history of liver disease with persistently abnormal liver function
• Liver tumours (benign or malignant)
• Known or suspected hormone-sensitive malignancy (e.g. breast cancer)
• Undiagnosed vaginal bleeding
• Pregnancy or suspected pregnancy
• Breastfeeding in the first 6 weeks postpartum
• Hypersensitivity to desogestrel, ethinylestradiol, or any excipient