Side by side

1. 1.Binds pituitary GnRH receptors with high affinity.
2. 2.Continuous stimulation desensitises the gland, so LH and FSH release falls.
3. 3.Testosterone or oestradiol drops to castrate or postmenopausal levels.
4. 4.The implant releases a steady dose, avoiding the peaks that would otherwise restore pulsatility.
5. 5.Suppression is reversible when the implant is stopped.

• Advanced and early prostate cancer
• Hormone-receptor-positive breast cancer in premenopausal women
• Endometriosis
• Endometrial thinning before resection
• Ovarian suppression in some fertility protocols

• Castrate testosterone levels within three to four weeks
• Reduced relapse and improved survival when added to tamoxifen in premenopausal breast cancer trials
• Substantial reduction in endometriosis pain
• Reversible menopause-like state with bone loss during treatment

• Hot flushes and sweats
• Reduced libido
• Bone mineral density loss
• Mood changes and fatigue
• Vaginal dryness
• Bruising or pain at the implant site
• Tumour flare at the start

Research context only - prescription medicine. A 3.6 mg implant every 28 days or a 10.8 mg implant every 12 weeks, placed subcutaneously in the abdominal wall, is the licensed pattern; endometriosis treatment is normally limited to six months because of bone density loss, and trials measure hormone suppression and bone mineral density at 6 and 12 months.

Research context only