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Frequently Asked Questions

  • No. Everyone who takes part in the study receives active treatment. There is no placebo group.

  • Your treatment depends on how severe your condition is, which is assessed based on the size of your testicles.

    There are two parts of the study (based on severity). Within each part, participants are randomly assigned to one of two treatment groups.

    Everyone in the study receives gonadotropin therapy. All participants will have the chance to receive both hCG and FSH if they need it.

  • Yes, you can still take part in the study. You will stop taking testosterone during the trial as the medications we give you will help you make your own. We will discuss the best way to transition from testosterone to gonadotropins with you.

  • We aim to make participation as convenient as possible.

    Where appropriate and if you are comfortable, we try to combine Visit 1 and Visit 2 on the same day. This first visit is the longest, as we give you plenty of time to discuss the study and decide if you would like to take part, and we collect baseline information.

    After this, there are 4-5 further visits over 18-24 months, and these are shorter and more straightforward.

  • No. Taking part is entirely voluntary. If you choose not to participate, your usual NHS care will not be affected in any way. If you do decide to take part, you are free to withdraw at any time, without giving a reason, and return to standard care.

  • No. Gonadotropin treatment is used in the study to help your testes develop and to support sperm production.

    Once this phase is complete (18-24 months), you will usually return to testosterone treatment for long-term maintenance (mood, bone health, energy, muscle strength, sexual function, and overall wellbeing).

    If you wish to have children in the future, you may need a short course of gonadotropin treatment again to restart sperm production.

  • Your GP and your usual paediatric or adult endocrine team will be informed that you are taking part, so they can support your care.

  • No, there is no payment for taking part in this study. We aim to arrange your care at a study site that is geographically convenient for you. If this is not possible, and travel costs may be a barrier, we can offer support with travel expenses to help make taking part possible.

  • After stopping gonadotropin treatment, the testes may become slightly smaller, but they will remain well developed compared to their original pre-treatment size.

  • The medications are given as small injections under the skin (similar to insulin injections). You (and/or your parent/carer) will be shown exactly how to do these safely at home.

  • Most people tolerate the treatment well. Possible side effects include acne and mild breast swelling (gynaecomastia) - both of which are similar to changes that can happen during normal puberty and are usually mild and manageable. You may also have discomfort at the injection site.

  • Yes, this treatment is designed to support testicular development and sperm production, which are important for fertility. However, responses vary between individuals, and we cannot guarantee fertility outcomes.

  • At each visit, we will check your progress. This will include a physical examination, blood tests, measurement of testicular size by ultrasound and, when appropriate, semen analysis. We will explain everything clearly at each stage.

  • We will ask for a semen sample to check sperm production, but only when your body is ready and if you feel comfortable. This is an important part of understanding how well the treatment is working, and we will discuss this with you in advance and support you through the process.

  • There is an option to participate in interviews, which are about your experience of the condition and treatment.

    They help us understand what it is like to go through puberty induction and live with this condition, so we can improve care in a more patient-centred way. Taking part is optional and involves one or two conversations during the study. During consent, you will be asked if you’re happy to be contacted by a member of our team (Dr Rachel Varughese), who will explain the interviews. You can then decide whether to take part.

  • Your progress will be monitored closely. If you are not responding as expected, the study team may adjust your treatment in line with the study protocol and your clinical care.

  • No. Your care will continue to be overseen by your usual clinical team. Taking part in the study is designed to fit alongside your routine NHS care.

  • You will be given contact details for your local study team, who you can reach at any time if you have questions, concerns, or experience any side effects.

  • Yes. Your personal information will be kept confidential and stored securely. Your data will be identified using a study ID number, and only authorised members of the research team will have access to your identifiable information.

  • Yes. A summary of the study results will be shared with participants once the study is completed.

  • Your samples will be used in this study to help understand hormone levels and the genetic causes of your condition. All samples are labelled with a study ID number (not your name). With your consent, some samples may be stored and used for future research related to puberty and reproductive health. You do not have to agree to this to take part in the study.