Everything you need to know about the combined contraceptive pill
- How the combined pill works
- Which brands are available in the UK
- How effective is the combination pill in practice?
- Who it suits and who should avoid the combination pill
- How to take it correctly: 21-day, 28-day, and everyday pill options explained
- Advantages and disadvantages compared to other contraceptive methods
- How to access it in the UK
How the combined contraceptive pill works
The combined pill prevents pregnancy through three complementary mechanisms.
Suppressing ovulation
The primary mechanism. Synthetic oestrogen and progestogen signal the pituitary gland to suppress the release of follicle-stimulating hormone (FSH) and luteinising hormone (LH), preventing the ovary from releasing an egg.
Thickening cervical mucus
Progestogen causes the mucus at the cervix to thicken, making it significantly harder for sperm to reach the uterus.
Thinning the uterine lining
Progestogen also thins the endometrium, making implantation less likely in the unlikely event that ovulation and fertilisation occur.
Together, these three mechanisms make the combined pill highly effective when used correctly.
Combined pill brands available in the UK
Several combined contraceptive pills are available on prescription in the UK, each containing different types or doses of oestrogen and progestogen. The choice between them is a clinical decision based on individual health history, tolerability, and response.
Commonly prescribed brands include:
- Microgynon 30 (levonorgestrel and ethinylestradiol 30 micrograms) is one of the most widely prescribed first-line options on the NHS
- Rigevidon (levonorgestrel and ethinylestradiol 30 micrograms) is the generic equivalent of Microgynon 30
- Gedarel (desogestrel and ethinylestradiol) is available in 20 microgram and 30 microgram oestrogen strengths
- Yasmin (drospirenone and ethinylestradiol 30 micrograms) contains an anti-androgenic progestogen; sometimes preferred for acne or fluid retention
- Cilest (norgestimate and ethinylestradiol) is a well-established combined pill, though availability has varied in recent years
- Marvelon (desogestrel and ethinylestradiol 30 micrograms) is a commonly used desogestrel-containing option
- Mercilon (desogestrel and ethinylestradiol 20 micrograms) lower oestrogen version of Marvelon
- Femodene (gestodene and ethinylestradiol) is a third-generation combined pill
- Loestrin 20 and Loestrin 30 (norethisterone and ethinylestradiol) is a lower oestrogen options
Good to know
Different progestogens have different properties. Some have more anti-androgenic activity (useful for acne or excess hair growth), while others have more androgenic activity. If one pill does not suit you, a different formulation may work better. A prescriber can guide this choice based on your individual history.
How effective is the combined pill?
The combined pill is highly effective when used correctly. With perfect use, fewer than 1 in 100 women will become pregnant over one year. With typical use, which accounts for human error such as missed pills, around 9 in 100 women will become pregnant over one year.
The gap between perfect and typical use underlines the importance of taking the pill consistently and correctly. Missing pills, taking certain medications that interact with the pill, or gastrointestinal illness that affects absorption can all reduce effectiveness.
Who is the combined pill suitable for?
The combined pill is suitable for most healthy women who want reliable contraception. However, it is not appropriate for everyone which is why a medical assessment before prescribing is required.
The combined pill may not be suitable if you:
- Smoke and are aged 35 or over
- Have a personal or family history of blood clots (venous thromboembolism)
- Experience migraine with aura
- Have high blood pressure or a history of cardiovascular disease
- Have a history of breast cancer or certain liver conditions
- Are breastfeeding a baby under six weeks old
- Have a BMI above 35
Important !
The combined pill is associated with a small increased risk of venous thromboembolism (VTE). NHS guidance notes that the risk of blood clots with the combined pill is very small but real, and is higher in women who smoke, are overweight, or have a personal or family history of blood clots. A prescriber will assess your individual risk profile before recommending the combined pill.
The progestogen-only pill (mini pill) may be suitable for women who cannot take oestrogen-containing contraception.
How to take the combined pill
Taking the combined pill correctly is essential for it to work as effectively as possible. The instructions vary slightly depending on which pack format you have been prescribed, so it is worth familiarising yourself with the specific guidance in your patient information leaflet alongside the general principles below.
21-day packs
Most combined pills come in 21-day packs. One tablet is taken daily for 21 consecutive days, followed by a seven-day pill-free interval during which a withdrawal bleed typically occurs. The next pack is started after the seven-day break, regardless of whether bleeding has finished.
28-day and everyday pill packs
Some combined pills come in 28-day packs containing 21 active tablets and 7 inactive (placebo) tablets. One tablet is taken every day without a break. The inactive tablets are taken during the seven-day interval, helping to maintain the daily habit and reducing the risk of missed pills.
Starting the pill
If you start the combined pill on the first day of your period, you are protected against pregnancy immediately. If you start on any other day of your cycle, you will need to use additional contraception such as condoms for the first seven days.
Important !
If you miss a pill, the guidance depends on when in your pack the pill was missed and how many have been missed. The FSRH provides detailed missed pill guidance, and most pill packets include a patient information leaflet with specific instructions. As a general rule, if you are more than 24 hours late taking a pill, use additional contraception for the next seven days and follow the instructions in your PIL.
Advantages and disadvantages
The combined pill suits many women well, but like all contraceptive methods it has both benefits and limitations. The table below compares it directly with the progestogen-only pill (mini pill) to help you understand the key differences, followed by a more detailed breakdown of the advantages and disadvantages of the combined pill specifically.
| Combined pill | Mini pill (progestogen-only) | |
|---|---|---|
| Effectiveness (perfect use) | Over 99% | Over 99% |
| Oestrogen-containing | Yes | No |
| Suitable for smokers over 35 | No | Yes |
| Suitable with migraine with aura | No | Yes |
| Regulates periods | Yes | Periods may become irregular or stop |
| May improve acne | Some formulations | Less consistent |
| Daily timing flexibility | Within same day | Must be taken within a 3-hour window (12 hours for desogestrel) |
| Requires prescription | Yes | Yes |
Advantages of the combined pill:
- Highly effective when taken correctly
- Regulates the menstrual cycle and can reduce period pain and heavy bleeding
- May improve acne with certain progestogen formulations
- Can reduce the risk of ovarian and endometrial cancer with long-term use
- Reversible with fertility typically returning quickly after stopping
Disadvantages of the combined pill:
- Not suitable for all women, particularly those with certain cardiovascular risk factors
- Associated with a small increased risk of VTE and, with long-term use, breast cancer
- Does not protect against sexually transmitted infections
- Requires daily pill-taking; missed pills reduce effectiveness
- May cause side effects including nausea, headaches, mood changes, and reduced libido, particularly in the first few months
Where to get the combined pill in the UK
The combined pill is available through several routes in the UK, both on the NHS and privately. All require a medical assessment before a prescription can be issued, as the pill is a prescription-only medicine and suitability varies between individuals.
Via your GP: GPs can prescribe the combined pill on the NHS following a consultation and blood pressure check. This is free of charge in England for eligible patients, and free in Scotland, Wales, and Northern Ireland.
Via a sexual health clinic: Sexual health clinics (also known as GUM clinics or contraception clinics) provide free contraceptive services including combined pill prescriptions. No GP referral is needed.
Via a pharmacist: Some pharmacies in England offer contraceptive pill consultations and prescriptions under the NHS Pharmacy Contraception Service without the need for a GP appointment.
Via a regulated online clinic: Private online clinics provide contraceptive consultations and prescriptions online.
Important !
The combined pill is a prescription-only medicine in the UK. It cannot be purchased without a valid prescription from a registered prescriber. Always ensure any online provider is registered with the GPhC at gphc.org.uk before proceeding.
Final thoughts
The combined contraceptive pill is a highly effective, reversible, and well-established form of contraception for most healthy women. The right pill for you depends on your individual health history, any existing conditions, and your personal preferences, all of which a prescriber can help you navigate.
FAQ
Is the combined pill safe?
For most healthy women, yes. The combined pill has an extensive safety record and is used by millions of women worldwide. It does carry a small increased risk of VTE and, with long-term use, a modest increase in breast cancer risk. These risks are small in absolute terms for most women and should be weighed against the benefits with a prescriber.
Can I take the combined pill every day?
If you are using a 21-day pack, you take the pill for 21 days followed by a seven-day break. If you are using a 28-day pack, you take one tablet every day without a break, including the seven inactive tablets during the pill-free interval. Some women choose to take active pills continuously (tricycling) to avoid withdrawal bleeds; discuss this with your prescriber before doing so.
How quickly does the combined pill work?
If started on the first day of your period, the combined pill is effective immediately. If started at any other time, additional contraception should be used for the first seven days.
Can the combined pill be used as emergency contraception?
No. The combined pill is a regular contraceptive and is not suitable for use as emergency contraception. If you need emergency contraception, contact your GP, pharmacist, or sexual health clinic promptly.
Does the combined pill protect against STIs?
No. The combined pill provides no protection against sexually transmitted infections. Condoms should be used alongside the pill if STI protection is needed.
What should I do if I miss a pill?
If you miss a combined pill, follow the instructions in your patient information leaflet. As a general guide, if you are more than 24 hours late, use additional contraception for the next seven days. If you have missed pills near the pill-free interval, you may need to skip the break. Your prescriber or pharmacist can provide specific guidance.
The DoktorABC medical advisory board
Dr. Roland Ruiken
Medical advisor, Norway
Dr. Viktor Simunovic
Medical advisor, Croatia