Goserelin

Zoladex

GnRH Agonist HRT SubQ FDA/EMA Label

Half-life

30 days

Time to Peak

7 days

Steady State

~150 days

Bioavailability

100%

Dose Range

3.6–10.8 mg

Frequency

Monthly

Overview

GnRH agonist delivered as a subcutaneous implant (biodegradable cylinder). Available in 1-month (3.6 mg) and 3-month (10.8 mg) implants. Inserted subcutaneously in the anterior abdominal wall using a pre-loaded syringe. Same mechanism as other GnRH agonists.

Mechanism of Action

Synthetic decapeptide GnRH agonist. Biodegradable implant provides continuous release, causing pituitary GnRH receptor downregulation and gonadal suppression.

Dosing Information

Route	Dose Range	Half-life	Tmax	Frequency
Subcutaneous (SubQ)	3.6–10.8 mg	30 days	7 days	Monthly, Every 3 months

Used in Regimens

1 regimen

NHS Pathway — Patches + GnRH Analogue

NHS Gender Dysphoria Clinic standard pathway: oestradiol patches with goserelin (Zoladex) GnRH analogue for testosterone suppression. Safest VTE risk profile. Goserelin implant every 1 or 3 months administered by GP or GIC nurse.

Zoladex 1-month implant for testosterone suppression.

hrt_fem

Ancillary

Data Sources

FDA Label Zoladex (goserelin acetate implant) FDA Prescribing Information

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