DIPHERELINE® (Triptorelin embonate)

Information in this fact sheet is meant to assist you in making decisions about your treatment. Always make medication decisions in consultation with your healthcare team.

What is Diphereline® used for?

Diphereline® is used to treat prostate cancer that has spread into surrounding tissue and/or to other parts of the body. It is not a cure for prostate cancer.

Diphereline® belongs to a group of medicines called Gonadotrophin Releasing Hormone analogues (GnRHa).

Most prostate cancers need a supply of the hormone testosterone to grow. Testosterone is produced by the testes and the adrenal glands.

Production of testosterone by the testes is stimulated by another hormone called luteinising hormone. This is produced by the pituitary gland, which is situated in the brain. Triptorelin, the active component of Diphereline®, reduces the production of luteinising hormone, which leads to a reduction in testosterone levels. This may shrink or slow down the development of the cancer.

Ask your doctor if you have any questions about why it has been prescribed for you. Diphereline® is available only with a doctor's prescription. Diphereline® can only be given by a doctor or a nurse.

What does Diphereline® look like?

Each pack contains 1 vial of Diphereline®, 1 ampoule, and 1 blister pack containing 1 empty polypropylene syringe and 2 needles.

The vial contains a small pellet of white to slightly yellow powder which must be mixed with the contents of the ampule (solvent) before injection.

How is Diphereline® given?

Diphereline® is given as an injection into your muscle (intramuscular) by your doctor or nurse.

How much and how often is it given? Diphereline® is available in three dose formulations:

  • 3.75mg injection usually given once a month
  • 11.25mg injection usually given once every 3 months (4 times a year)
  • 22.5mg injection usually given every 6 months (2 times a year).

Your doctor will prescribe which dose formulation is most suitable for you.

What are the common side effects?

Tell your doctor, nurse or pharmacist as soon as possible if you do not feel well while you are receiving Diphereline®.

Diphereline® helps most people with prostate cancer, but it may have unwanted side effects in a few people. It can be hard to work out whether side effects are caused by Diphereline® or prostate cancer.

Generally the side effects are mild but you may need medical attention if you get some of the side effects.

If you get any side effects, do not cancel your follow-up dose of Diphereline® without first talking to your doctor. Tell your doctor, nurse or pharmacist if you notice any of the following side effects and they worry you.

Very common side effects affecting more than 1 in 10 patients:

  • hot flushes
  • feeling weak
  • back pain
  • pins and needles sensation in the legs
  • excess sweating.

Common side effects affecting more than 1 in 100 patients:

  • nausea
  • tiredness
  • mood changes, depression
  • redness, swelling, pain and /or bruising at the injection site
  • swelling of the hands and feet (oedema)
  • muscle and bone pain, pain in arms and legs
  • dizziness, headache
  • impotence, loss of libido.

What are the less common side effects?

Tell your doctor immediately, call an ambulance or go to an Emergency Department at your nearest hospital if any of the following rare side effects happen as you may need urgent medical attention:

  • sudden signs of allergy such as rash, itching or hives on the skin
  • swelling of the face, lips, tongue or other parts of the body
  • shortness of breath, wheezing or trouble breathing
  • chest pain
  • sharp, stabbing pain or swelling in your lower leg
  • swelling and redness along a vein which is extremely tender when touched
  • seizures or convulsions.

Tell your doctor, nurse or pharmacist as soon as possible if you notice any of the following side effects which may be serious and require medical attention:

  • sudden headaches
  • severe back pain
  • difficulty breathing
  • temporary worsening of symptoms of your cancer (tumour flare)
  • high blood pressure
  • gout (a disease with painful swollen joints, particularly in the big toe)
  • inability to pass urine.


Macmillan 2013, Triptorelin (Decapeptyl ® SR, Gonapeptyl Depot ®), Macmillan Cancer Support, viewed 2nd July 2013.

TGA Consumer Medical Information (CMI), Oct 2012, Diphereline, Therapeutic Goods Administration, Canberra, viewed 2nd July 2013.


Prostate Cancer Foundation of Australia develops materials based on best available evidence and takes advice from recognised experts in the field in developing such resource; however it cannot guarantee and assumes no legal responsibility for the currency or completeness of the information.