Zelleta is a progestogen-only pill (POP) — commonly referred to as the mini pill — containing 75 micrograms of desogestrel. Unlike the combined pill, Zelleta contains no oestrogen, making it a suitable option for a wider group of women, including those who are breastfeeding, those over 35 who smoke, and those in whom oestrogen-containing contraceptives are contraindicated.

What Is Zelleta and How Does It Work?

Zelleta contains desogestrel, a synthetic progestogen that mimics the body’s natural progesterone. It prevents pregnancy through three mechanisms:

• Suppresses ovulation — desogestrel consistently inhibits the hormonal signals that trigger egg release, the primary mechanism of action that distinguishes desogestrel POPs from older norethisterone-based mini pills
• Thickens cervical mucus — making it harder for sperm to penetrate and reach an egg
• Thins the endometrium — altering the uterine lining to reduce the likelihood of implantation

The suppression of ovulation gives desogestrel-based pills like Zelleta a wider 12-hour missed-dose window compared to the 3-hour window of older norethisterone POPs — an important practical advantage.

Who Is Zelleta Suitable For?

How Effective Is Zelleta?

When taken correctly — one pill every day within the same 12-hour window, without interruption — Zelleta is over 99% effective. In typical real-world use, the failure rate is approximately 9 per 100 women per year, largely due to missed or delayed doses. Consistent daily timing is therefore critical to maximising effectiveness.

Side Effects of Zelleta

Like all hormonal contraceptives, Zelleta can cause side effects, though these vary considerably between individuals. Many women tolerate it very well. The most common include:

• Irregular bleeding or spotting — the most frequently reported effect; bleeding patterns often settle after 2–3 months of use
• Amenorrhoea — periods stopping altogether, which some women find desirable
• Acne or skin changes
• Mood changes or low mood
• Reduced libido
• Headaches
• Breast tenderness
• Nausea

What to Do If You Miss a Zelleta Pill

Zelleta’s 12-hour missed-dose window (wider than traditional mini pills) gives more flexibility. Here is what to do:

• If less than 12 hours late: take the missed pill immediately and continue as normal — no additional contraception needed
• If more than 12 hours late: take the missed pill immediately (even if this means taking two in one day), then continue as normal — use additional contraception (condoms) for the next 48 hours
• If you had unprotected sex in the 48 hours before missing the pill, consider emergency contraception
• Set a daily phone alarm to help maintain consistent timing

Zelleta and Weight

Clinical evidence does not confirm that Zelleta directly causes weight gain. Any changes in weight reported by some users are likely related to water retention during certain phases of the menstrual cycle or to other individual factors rather than to the pill itself. If significant or unexplained weight change occurs, speak with a prescriber.

Stopping Zelleta and Returning Fertility

Zelleta is fully reversible. Fertility typically returns quickly — often within the first or second natural cycle after stopping. Some women ovulate as soon as they stop taking the pill. There is no evidence that previous use of the progestogen-only pill impairs long-term fertility.

Zelleta vs Other Mini Pills

Zelleta (desogestrel 75mcg) is bioequivalent to Cerazette — both contain the same active ingredient and dosage. They differ only in packaging and price. Other progestogen-only pills based on norethisterone (Micronor, Noriday) work primarily by thickening cervical mucus rather than by suppressing ovulation, and have a narrower 3-hour window for missed doses. Desogestrel-based pills are generally considered the first choice modern POP for this reason.