Subcutaneous hormone implants are currently unavailable whilst the MHRA undertakes a review.

Until recently, these implants were available from a small number of specialist centres in the UK and they are an important option for women who fail to respond to standard delivery routes. HRT implants, for this group of women, can result in better circulating estradiol levels than are achieved with oral or standard transdermal delivery routes, including patches, gel and spray, and this can improve symptom control. For reasons that are not always clear, some women do not respond to oral and transdermal HRT and oral HRT may be contraindicated due to risk factors for venous thromboembolism, which include obesity (BMI > 30).

Many of the women who are prescribed HRT implants have experienced surgical menopause, and this includes younger women who often require higher levels of estradiol to fully alleviate symptoms, and also to protect against long term risks of early surgical menopause such as osteoporosis. Although the numbers are relatively small compared with the general population of menopausal women, for this small significant group, ensuring effective delivery of hormones with implants is really important.

We feel strongly that hormone implants should remain available for the treatment of menopausal symptoms in women who do not respond favourably to other options1,2,3. Hormone implants have been used for more than fifty years and safety data are comparable with other non-oral routes of administration4,5. As long as appropriate doses are used at appropriate intervals, inappropriately high estradiol levels can be avoided.

The value of HRT implants for women with suboptimal symptom control was the focus of two recent papers published in the BMS journal, Post Reproductive Health6,7. The British Menopause Society is happy to collaborate with MHRA, supporting their review of HRT implants.

References:

  1. Brincat M, Magos A, Studd J W, et al. Subcutaneous hormone implants for the control of climacteric symptoms. A prospective study. Lancet 1984; (8367): 16-1
  2. Garnett T, Studd J, Watson N, et al. The effects of plasma estradiol levels on increases in vertebral and femoral bone density following therapy with estradiol and estradiol with testosterone implants. Obstet Gynecol 1992; 79(6): 968-972
  3. Savvas M, Studd JWW, Fogelman I, et al. Skeletal effects of oral estrogen compared with subcutaneous estrogen and testosterone in post-menopausal women BMJ 1988; 297: 331-333
  4. Donovitz GS. Low complication rates of testosterone and estradiol implants for androgen and estrogen replacement therapy in over 1 million procedures. Ther Adv Endocrinol Metab 2021; 12: 204201882110152
  5. Donovitz G and Cotton M. Breast cancer incidence reduction in women treated with subcutaneous testosterone: testosterone therapy and breast cancer incidence study. Eur J Breast Health 2021; 17(2): 150-156.
  6. Dixit A, Carden N, Stephens E, et al. Hormone replacement therapy subcutaneous implants for refractory menopause symptoms; the patient perspective. Post Reprod Health 2022; 28(2): 79-91
  7. Tamnlyn J, Robinson L, Maguire E et al Subcutaneous Hormone Implants. Post Reprod Health 2023; 29 (4): 240-243.