Hormone blockers.
GnRH analogues (Decapeptyl, Prostap, Zoladex) prescribed as part of adult hormone therapy. We do not, under any circumstances, prescribe these medications to anyone under the age of 18.
Important: please read
The Gender Hormone Clinic only prescribes GnRH analogues to patients aged 18 and over.
We do not assess, prescribe, or provide repeat prescriptions for hormone blockers for anyone under 18, including under the Cass Review framework, private routes, or in any other context. If you are under 18 and looking for support, please speak to your GP or contact a specialist NHS gender service.
What they are
A reversible pause on sex-hormone production.
GnRH analogues (gonadotropin-releasing hormone analogues) are medications that suppress the body's production of testosterone and oestrogen. They are licensed for several conditions including endometriosis, prostate cancer, and central precocious puberty, and are also used in adult gender care alongside or before standard hormone therapy.
In adult gender care, blockers may be considered when reducing endogenous hormone activity is clinically helpful: for example, when oestrogen alone is not sufficiently suppressing testosterone, or as an alternative to oral anti-androgens like spironolactone or cyproterone. Their effect is reversible: stopping the medication restores baseline hormone production.
Blockers are not a standalone gender-affirming treatment in adults. They are a clinical tool used as part of an overall hormone therapy plan, after a full assessment with one of our clinicians.
Medications we work with
Three GnRH analogues, depot injection.
Leuprorelin · 4 or 12-weekly
Prostap
The blocker we most commonly prescribe. A subcutaneous depot given every 12 weeks (a 4-weekly form also exists), usually at a GP practice on shared care.
Triptorelin · 12-weekly
Decapeptyl
An alternative deep IM injection given every 12 weeks, used when Prostap is unavailable or not tolerated.
Goserelin · 4 or 12-weekly
Zoladex
Implant inserted subcutaneously. Used selectively where it suits the patient's situation better.
Detailed dosing, side effects, and monitoring information is in our medication guides. See the full medication library.
When we consider blockers
A clinical decision, not a default.
Most commonly
As an anti-androgen alternative
For some transfeminine patients, oral anti-androgens (spironolactone, cyproterone) are not tolerated, are contraindicated, or do not bring testosterone fully into the target range. A 12-weekly depot can be a more reliable alternative.
Less commonly
Pre-surgery or pre-fertility planning
Surgical teams sometimes ask for full suppression in the months before a procedure. Blockers are also occasionally used while a patient explores fertility preservation before starting cross-sex hormones.
Important context
Bone density & long-term safety
Sustained low sex-hormone levels (whether from blockers used alone or before adequate cross-sex hormone replacement) affect bone mineral density. We monitor accordingly, and almost always pair blocker use with concurrent oestrogen or testosterone therapy rather than running blockers in isolation.
Side-effect monitoring includes bone density (DEXA), cardiovascular markers, and mental-health check-ins, as outlined by WPATH SOC 8.
For under-18s
We are an adult gender clinic.
The Gender Hormone Clinic provides care to people aged 18 and over only. We do not assess, prescribe, or arrange shared-care for hormone blockers for anyone under 18, regardless of circumstances or referral route. This applies to new prescriptions, ongoing prescriptions started elsewhere, and any private or NHS arrangement.
If you are under 18, your route in the UK is via your GP and the NHS Children and Young People's Gender Service. Independent regulators have set out clear restrictions on private under-18 prescribing of blockers, and we work strictly within those.
We are happy to be in touch about adult care once you turn 18. We book initial appointments from the day of an 18th birthday onwards, and many of our patients come to us in their late teens or early 20s.
Common Questions
FAQs about
GnRH blockers
A few of the questions adult patients ask most often, with our AI assistant on hand for anything else.
Common questions about getting started
Costs, diagnosis, locations and timings: the things most people ask before they enquire.
Adult patient with a question?
Send us an enquiry and one of our clinicians will be in touch about whether GnRH analogues fit your situation.