Reviewed by a GPhC-registered Pharmacist at Newdays Pharmacy
Quick Answer: The combined oral contraceptive pill (COCP) contains both oestrogen and progestogen and is taken for 21 days with a seven day break (or continuously in some regimens). The progestogen only pill (POP), often called the mini pill, contains only progestogen and is taken every day without a break. Both are highly effective when taken correctly. The right choice depends on your health history, lifestyle, and preferences.
What Is the Combined Oral Contraceptive Pill?
The combined oral contraceptive pill (COCP) contains synthetic versions of two female hormones: oestrogen (usually ethinylestradiol) and progestogen (in one of several forms including levonorgestrel, norethisterone, gestodene, desogestrel, or drospirenone). There are many branded and generic versions available in the UK.
The COCP primarily works by preventing ovulation. It also thickens cervical mucus (making it harder for sperm to reach an egg) and thins the lining of the uterus. When taken correctly, it is more than 99% effective at preventing pregnancy.
What Is the Progestogen Only Pill (Mini Pill)?
The progestogen only pill (POP) contains only a progestogen hormone. It is taken every day without a break. Older POP formulations work mainly by thickening cervical mucus. Desogestrel containing POPs (such as Cerazette) also reliably inhibit ovulation in most users.
The POP must be taken within a strict daily window: a three hour window for most formulations (for example norethisterone based) or a twelve hour window for desogestrel based pills. When taken correctly, it is also more than 99% effective.
Key Differences Between the Combined Pill and Mini Pill
- Hormones: COCP contains oestrogen and progestogen; POP contains progestogen only
- Daily schedule: COCP takes 21 days on and seven days off (or similar); POP is taken every day with no break
- Timing strictness: COCP is generally more forgiving for missed doses; POP has a shorter window for missed pills
- Periods: COCP typically produces a regular withdrawal bleed; POP may cause irregular, lighter, or absent periods
- Oestrogen side effects: Only relevant with COCP and not present with POP
Who Should Not Take the Combined Pill?
The combined pill is not suitable for everyone. Key contraindications include:
- Personal history of deep vein thrombosis (DVT), pulmonary embolism (PE), or blood clotting disorders
- Migraines with aura (migraine with focal neurological symptoms)
- High blood pressure (uncontrolled hypertension)
- Cardiovascular disease or significant cardiovascular risk factors
- Liver disease
- Breastfeeding mothers in the first six weeks after birth
- Women aged 35 or over who smoke
The UK Medical Eligibility Criteria for Contraceptive Use (UKMEC), published by the Faculty of Sexual and Reproductive Healthcare (FSRH), provides detailed guidance. A pharmacist or clinician will assess your medical history before prescribing.
Who Can Benefit from the Mini Pill?
The progestogen only pill is often preferred for or recommended to:
- Women who cannot take oestrogen for medical reasons (see above)
- Women who are breastfeeding
- Women aged 35 or over who smoke
- Women with migraines with aura
- Women with well controlled hypertension
It is important to note that the POP is not suitable for everyone either. A full clinical assessment is required before any contraceptive pill is prescribed.
Can I Get the Contraceptive Pill From a Pharmacy in the UK?
Yes. Under the NHS Pharmacy Contraception Service and private prescribing pathways, pharmacies in England can supply hormonal contraception including the combined pill and progestogen only pill. Pharmacist prescribers can assess, prescribe, and supply contraception in an increasingly wide range of settings.
At Newdays Pharmacy, our pharmacists can assist with contraception consultations at our branches in Eton (Windsor), Twyford, Reading (Coley Park), and Lane End. Contact us to find out about current service availability.
Book Now: Book a Contraception Consultation
Frequently Asked Questions
Is the combined pill or mini pill better for acne?
Some combined pills, particularly those containing cyproterone acetate (co-cyprindiol / Dianette) or drospirenone, have a clinical indication for acne treatment in women. The progestogen only pill does not have this indication and may worsen acne in some individuals, although individual responses vary.
Can the combined pill cause weight gain?
Large scale clinical studies have not demonstrated a consistent causal link between modern combined oral contraceptives and significant weight gain. Some women report changes in weight or water retention, but the evidence does not support the pill as a direct cause of sustained weight gain for most women.
What happens if I miss a pill?
What to do depends on which pill you take. Follow the patient information leaflet or ask your pharmacist. As a general guide: for the COCP, if you have missed one pill, take it as soon as you remember and take the next pill at the usual time. If you have missed two or more pills in a row, use additional contraception (condoms) for seven days and seek advice. For the POP, take the missed pill as soon as possible and use condoms for 48 hours if it was more than three hours (twelve hours for desogestrel) late.
Clinical Disclaimer: This article is intended for general information only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any treatment or medication. Information is accurate as of the date of publication and reviewed by a GPhC-registered pharmacist. Newdays Pharmacy is registered with the General Pharmaceutical Council (GPhC).