Mirena® (52mg levonorgestrel IUS) authorised in the UK for extended use up to eight years for contraception

  • Mirena® (52mg levonorgestrel IUS), Bayer’s long-acting reversible intrauterine system (IUS), received regulatory approval on a label update in the UK for up to eight years in contraception,1 offering the longest contraceptive duration of use for any hormonal intrauterine system2
  • The IUS is one of the most effective birth control methods3
  • Mirena remains licensed for five years for the treatment of idiopathic menorrhagia (heavy menstrual bleeding) with symptom-driven extended use for up to eight years following the initial five years of use.1

Bayer announced today that the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) has authorised its 52mg levonorgestrel (LNG) releasing intrauterine system (IUS) Mirena® for extended use up to eight years for contraception in the UK. The authorisation is based on the results of the Mirena Extension Trial (MET), evaluating the contraceptive efficacy and safety profile of Mirena ® during extended use beyond five years and up to eight years (n=362), which demonstrated that contraceptive efficacy remains high with greater than 99% during years six to eight (Pearl-Index, a measure of contraceptive efficacy, 0.28 [95% CI (0.03, 1.00)]) and showed a consistent adverse reaction profile in Years 6 through 8.1 


Dr Diana Mansour, Consultant in Community Gynaecology, Newcastle Hospitals, Community Health, and Past Vice President of the Faculty of Sexual and Reproductive Healthcare (FSRH), said: “Women in the UK will welcome the news that the Mirena levonorgestrel intrauterine system has now been granted an 8-year license for contraception and has a 5-year license for the treatment of heavy menstrual bleeding or, until symptoms return, up to 8 years. Some women may find the fitting or changing of an intrauterine device uncomfortable or embarrassing. Increasing the length of time when a device can be effective for contraception and heavy menstrual bleeding will help reduce these concerns as well as the potential risk of complications.”


The label update also includes symptom-driven extended use for the indication idiopathic menorrhagia (heavy menstrual bleeding). Mirena has a five-year license for the treatment of heavy menstrual bleeding. Should symptoms not return after five years of use, Mirena can be considered for continued use for up to eight years. The IUS should be removed or replaced after eight years at the latest.


“We are pleased to be able to offer women in the UK the extended use of Mirena in contraception, allowing a reduction in the number of IUS removal and insertion procedures for those who choose the IUS as their contraceptive method,” said Dr Joep Hufman MD, Medical Director at Bayer UK & Ireland. “Bayer is committed to driving innovation in women’s healthcare and delivering solutions to meet women’s needs throughout key stages of their reproductive lives. We will continue to support women and their healthcare professionals to make individual decisions for a specific contraceptive method based on personal needs.”


LNG-IUS is one of the most effective methods of birth control as it does not require user interventions such as daily dosing or monthly administration.4 It can be removed by the doctor at any time and offers rapid return to a woman’s natural level of fertility following removal.4 A LNG-IUS should only be inserted after a comprehensive discussion and evaluation of all contraceptive options aligned with the individual woman’s needs.5 




Bayer Media Contact:

Veronica Yao, +44 (0)7870 485926

E-mail: veronica.yao@bayer.com


Notes to Editors


About contraceptive efficacy & clinical trial study

The contraceptive efficacy of Mirena has been studied in five large clinical trials involving 3,330 women.1 The Pearl Index (a measure of contraceptive efficacy) was 0.21 ([95% CI] 0.08, 0.45) in the first year and cumulatively, contraception failed by 0.71% ([95% CI] 0.37, 1.33) over five years.1 The contraceptive effectiveness of Mirena beyond five years (including years six to eight) was studied in the Mirena Extension Trial involving 362 women. Based on 2 pregnancies (1 in Year 6 and 1 in Year 7) and 10,216 exposure cycles, the cumulative pregnancy rate at the end of the 3-year period of extended use (Years 6, 7 and 8) was 0.68% with a 95% upper confidence limit of 2.71%. The study confirmed a positive benefit risk profile with no new or unexpected safety findings. The eight-year data from the extension trial were published in abstract form at the American College of Obstetricians and Gynecologists (ACOG) in 2022.6 The full paper is published in 2022 in the American Journal of Obstetrics and Gynecology at https://doi.org/10.1016/j.ajog.2022.09.007. Information about this trial can be found at https://clinicaltrials.gov/ct2/show/study/NCT02985541.


About Mirena®

Mirena is a T-shaped device containing 52 mg of synthetic levonorgestrel. Once placed in the uterus, it continuously releases small amounts of levonorgestrel directly into the uterus. Mirena is a long-acting reversible contraceptive (LARC) and can be removed at any time by a healthcare provider if a woman’s plans change. Mirena is available in many countries across all continents. The approved indications in the UK are: contraception (prevention of pregnancy) for up to eight years of use; idiopathic menorrhagia (excessive menstrual bleeding) for up to five years; for idiopathic menorrhagia, if symptoms have not returned after five years of use, continued use of the system may be considered for up to eight years; protection from endometrial hyperplasia (excessive growth of the lining of the uterus) during oestrogen replacement therapy for up to four years.


About Women’s Healthcare at Bayer

Bayer is a recognised global leader in women’s healthcare, with a long-standing commitment to delivering science for a better life by advancing a portfolio of innovative treatments. Bayer offers a wide range of effective short- and long-acting contraception methods as well as therapies for gynaecological conditions. Today, Bayer’s research efforts focus on finding new treatment options for gynaecological conditions with a high medical need and includes several investigational compounds in various stages of pre-clinical and clinical development. Together, these projects reflect the company’s approach to research, which prioritises targets and pathways with the potential to alter the way that gynecological conditions are treated. Additionally, Bayer intends to provide 100 million women in low-and-middle income countries by 2030 with access to family planning by funding multi-stakeholder aid programmes and by ensuring the supply of affordable modern contraceptives. This is part of the comprehensive sustainability measures and commitments from 2020 onwards and in line with the Sustainable Development Goals of the United Nations. 


About Bayer

Bayer is a global enterprise with core competencies in the life science fields of health care and nutrition. Its products and services are designed to help people and planet thrive by supporting efforts to master the major challenges presented by a growing and aging global population. Bayer is committed to driving sustainable development and generate a positive impact with its businesses. At the same time, the Group aims to increase its earning power and create value through innovation and growth. The Bayer brand stands for trust, reliability, and quality throughout the world. In fiscal 2022, the Group employed around 101,000 people and had sales of 50.7 billion euros. R&D expenses before special items amounted to 6.2 billion euros. For more information, go to www.bayer.co.uk.



Forward-Looking Statements 

This release may contain forward-looking statements based on current assumptions and forecasts made by Bayer management. Various known and unknown risks, uncertainties and other factors could lead to material differences between the actual future results, financial situation, development or performance of the company and the estimates given here. These factors include those discussed in Bayer’s public reports which are available on the Bayer website at www.bayer.co.uk. The company assumes no liability whatsoever to update these forward-looking statements or to conformthem to future events or developments. 




  1. Mirena® 20 micrograms/24 hours intrauterine delivery system. Summery of Product Characteristics (SmPC). 
  2. Levonorgestrel-containing IUS comparison. Great Manchester Medicines Management Group. GMMMG NHS. https://gmmmg.nhs.uk/wp-content/uploads/2022/09/IUS-comparison-table-update-July-2022-final-for-web.pdf. Last accessed: January 2024.
  3. Contraceptive Methods: Effectiveness. Contraception Choice. University College London. https://www.contraceptionchoices.org/infographic. Last accessed: January 2024. 
  4. FPA. IUS (Intrauterine system). Sexwise. https://www.sexwise.org.uk/contraception/ius-intrauterine-system. Last accessed: January 2024. 
  5. FSRH Guideline Intrauterine Contraception. Faculty of Sexual and Reproductive Healthcare. Available at: https://www.fsrh.org/documents/ceuguidanceintrauterinecontraception/fsrh-clinical-guideline-intrauterine-contraception-mar23-amended-11jul2023-.pdf. Last accessed: January 2024. 
  6. Jensen JT, Lukkari-Lax E, Schulze A, et al. Contraceptive efficacy and safety of the 52-mg levonorgestrel intrauterine system for up to 8 years: findings from the Mirena Extension Trial. Am J Obstet Gynecol 2022;227:873.e1-12.


RP-MIR-GB-0175 / January 2024