Question to the Department of Health and Social Care:

To ask His Majesty's Government how many yellow card reports of serious adverse effects have been received in each of the past 15 years for children aged (1) 0–9 years old, and (2) 10–16 years old, who were prescribed puberty blockers to treat central precocious puberty, including goserilin, leuprorelin, triptorelin and other gonadotropin-releasing hormone agonists; and whether any of those reports included adverse effects on bone health.

Answered by Baroness Merron - Parliamentary Under-Secretary (Department of Health and Social Care)

The Medicines and Healthcare products Regulatory Agency (MHRA) is responsible for ensuring medicines, medical devices, and blood components for transfusion meet applicable standards of safety, quality, and efficacy. The MHRA rigorously assesses the available data, including from the Yellow Card scheme, and seeks advice from the Commission on Human Medicines, the MHRA’s independent advisory committee, where appropriate, to inform regulatory decisions, including amending the product information.

Puberty blockers are also known as gonadotrophin-releasing hormone analogues or ‘GnRH analogues’. These medicines are licenced for conditions such as young children who enter puberty too early, also known as precocious puberty, prostate cancer, and endometriosis. The GnRH analogues included in this search were buserelin, leuprorelin, goserelin, gonadorelin, nafarelin, and triptorelin. Please note it is not mandatory to provide information on indication when submitting an adverse drug reaction report.

The MHRA has received a total of 17 serious United Kingdom suspected adverse drug reaction reports in the past 15 years of GnRH analogues in children aged between zero to nine years old, with 16 reports, and 10 to 16 years, with one report, between 1 January 2011 and 31 December 2025, where the indication for use was reported as precocious puberty. Of these 17 reports, two included an adverse effect on bone health, namely bone marrow failure and epiphysiolysis, or growth plate fracture.

It is important to note that a reaction reported to the Yellow Card scheme does not necessarily mean it has been caused by the medicine, only that the reporter had a suspicion it may have. Underlying or concurrent illnesses may be responsible, or the events could be coincidental.

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