Women's health
Progestogen-only contraception
The progestogen-only pill, implant, injection and IUS — Oestrogen-free contraception suitable when combined methods are not — including while breastfeeding.
Education and reference only. This is a plain-language class overview — it deliberately contains no doses. Always check the current Summary of Product Characteristics (SmPC), the BNF and your local formulary before prescribing or administering any medicine.
What it is
Progestogen-only contraception prevents pregnancy without oestrogen, making it suitable for many women who cannot or prefer not to use combined methods. It includes the progestogen-only pill, the implant, the injection and the intrauterine system.
How it works
Depending on the method, progestogen thickens cervical mucus to block sperm, thins the womb lining, and (with the implant, injection and some pills) suppresses ovulation. The long-acting methods remove the need to remember a daily pill, which is partly why they are so effective.
In practice
In practice progestogen-only methods are the go-to when oestrogen is unsuitable — for example with migraine with aura, a history of clots, higher cardiovascular risk, or while breastfeeding — because they avoid the oestrogen-related clot risk. They span a wide range, from the daily progestogen-only pill (one type of which now has a more forgiving missed-pill window) to long-acting, highly reliable options: the implant, the injection and the intrauterine system (IUS). The common counselling point is bleeding-pattern change — periods may stop, become irregular or be more frequent, which is harmless but a frequent reason people stop, so setting expectations helps. The injectable form has a reversible effect on bone density worth discussing with very long-term use, and return of fertility after it can be delayed; the implant and IUS are among the most effective contraceptives available.
Examples
Practical use
How to take it & use it well
- Progestogen-only methods include the progestogen-only pill (POP), the implant, the injection and the intrauterine system (IUS); use the one prescribed as directed.
- If you use the progestogen-only pill, take it at around the same time each day, as some types have a narrow window for late pills.
- The implant, injection and IUS are fitted or given by a trained clinician and last for set periods, so note when they are due to be renewed.
- Expect your bleeding pattern to change - periods may become irregular, lighter, stop or, for some, more frequent at first.
- Tell your clinician if you start a medicine that could reduce effectiveness, so backup contraception can be advised if needed.
Common uses
- Contraception when oestrogen is unsuitable (e.g. migraine with aura, clot history, breastfeeding)
- Long-acting reversible contraception (implant, IUS)
- Heavy menstrual bleeding (the IUS)
Monitoring
- Acceptability of the bleeding pattern
- Blood pressure and a review at the appropriate interval for the method
- For the injection, periodic review of continued use over years
Weighing it up
Advantages & disadvantages
Advantages
- Contains no oestrogen, so it suits people who cannot use oestrogen, such as some breastfeeding mothers or those with certain risk factors.
- Long-acting forms (implant, injection, IUS) are very effective and do not rely on remembering a daily pill.
- The IUS and some pills can make periods lighter and less painful.
- Quickly reversible for most methods, with fertility usually returning soon after stopping (the injection can take longer).
Disadvantages
- Unpredictable bleeding patterns are common, which some people find bothersome.
- The progestogen-only pill needs consistent daily timing to stay reliable.
- Possible side effects include acne, mood changes, breast tenderness or headaches.
- Does not protect against sexually transmitted infections, so condoms may still be needed.
- The injection may be linked to a temporary reduction in bone density and slower return of fertility.
Key safety principles
What to watch for
- Changes in bleeding pattern are common (no periods, irregular or frequent bleeding) — harmless but a common reason for stopping.
- The injection has a reversible effect on bone density (relevant with very long-term use) and fertility may take time to return after it.
- No protection against sexually transmitted infections; the progestogen-only pill needs reasonably consistent timing.
Key interactions
What to avoid or check alongside
- Enzyme-inducing medicines (some epilepsy drugs, rifampicin): can reduce the effectiveness of the pill and implant, so additional or alternative contraception may be needed.
- St John's wort: can lower the effectiveness of progestogen-only pills.
- Some HIV medicines: can affect hormone levels and contraceptive reliability.
- Other contraceptive hormones: methods are not usually combined without advice.
Patient & carer advice
- Your bleeding pattern is likely to change — this is normal
- The implant and IUS are fitted and last for years; the pill needs taking regularly
- Use condoms as well to protect against infections
Use with
Related clinical calculators
Dose and risk decisions for this class often depend on renal function, weight or bleeding/stroke risk. These tools help:
Answers
Progestogen-only contraception: frequently asked questions
How is progestogen-only contraception different from the combined pill?
It contains progestogen only, with no oestrogen. This makes it suitable for many people who cannot use oestrogen, such as some who are breastfeeding or who have certain clot or migraine risk factors.
Why has my bleeding pattern changed?
Irregular bleeding, spotting, lighter periods or no periods are all common with progestogen-only methods and are usually not harmful. If bleeding is heavy, persistent or worrying, ask your clinician to review it.
Which methods do not rely on remembering a daily pill?
The implant, injection and intrauterine system (IUS) are long-acting and very effective because they do not depend on taking something each day. They are fitted or given by a clinician and last for set periods.
Will my fertility return quickly after stopping?
For most progestogen-only methods, fertility usually returns soon after stopping. The injection is an exception, as it can take several months longer for fertility to come back.
Authoritative sources
Always verify against the source
This overview is for orientation. For doses, interactions, contra-indications and the full monograph, use:
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