Sustanon UK - Sustanon testosterone injection

Immediate application and less frequent dosing.


Sustanon can be injected once every 5-7 days and will ensure steady blood levels.

Contact safe

Sustanon cannot be transferred to loved ones. Once injected it stays under the skin, allowing personal contact with women and children.

Potential complications

Sustanon requires extra ancillaries and disposal. There is a low risk of infections and complications if injected incorrectly. It contains peanut oil so it isn’t suitable for those who suffer from peanut allergies.

What is Sustanon?

Sustanon is a very common injectable form of testosterone which is widely used in the UK and the European Union as well as other parts of the world.

Sustanon is a popular choice with doctors, patients and anabolic steroid users because it can be injected relatively infrequently and maintains testosterone levels over this time scale.

It does have some downsides which we will look at later.

Sustanon is made up of four esters which release testosterone into the body at different speeds.

The ester is a ‘tail’ added to the testosterone – the longer it is the more slowly the testosterone is released into the body.

Sustanon is used for the treatment of low testosterone in men. It is an injectable and comes in a peanut oil, so it is not suitable for peanut allergy sufferers.

It is one option for testosterone replacement therapy in men with low or no production of natural testosterone (hypogonadism).

How does Sustanon work?

Sustanon and enanthate are oils that contain the active ingredient testosterone, which is the same as the naturally occurring male hormone testosterone.

Sustanon contains four compounds which release testosterone into the body at differing rates. This allows a more steady blood level to be sustained.

Sustanon enanthate injections replace the testosterone produced in your body to ensure normal levels. This is why it is called testosterone replacement therapy. 

Testosterone is known as an androgen – one of the male steroidal hormones. It is produced mainly by the testicles and is the main hormone essential for normal male growth and development. It is responsible for the development of the male sex organs and male sexual characteristics. It is also very important for mood, energy levels, sexual desire and physical strength.

Testosterone in men is essential for the production of sperm, the maintenance of erectile potency, and the functioning of the prostate gland and other reproductive structures. It also has functions in the skin, muscles, skeleton, kidney, liver, bone marrow and central nervous system. Read more here on what testosterone is.

Low levels of testosterone can cause decreased sex drive, inability to achieve an erection, infertility (due to decreased sperm production), decreased mental and physical activity, fatigue and weakening of bones (osteoporosis).

Sustanon injections are given as testosterone replacement therapy when natural testosterone levels fall too low, causing the issues above.

Natural testosterone levels often fall with age and fall rapidly following surgical removal of the testicles. They also fall due to decreased functioning of the testicles (hypogonadism or eunuchoidism), or by decreased gonadotrophin production by the pituitary gland, as a result of pituitary disease.

There are many reasons that men nowadays appear to have testosterone levels 20% lower than they were 20 years ago. Testosterone replacement therapy allows testosterone levels to return to normal, thus relieving the symptoms.

TRT is still contentious in the UK, and the normal male testosterone levels are still often misunderstood, making treatment difficult for many.

Benefits of Sustanon injections:

  • Steady blood levels are achieved in most men with good results
  • Application every 5 to 7 days
  • No mess
  • No risk of transferring to women and children through contact
  • Cost effective

Negatives of Sustanon

  • It has high levels of preservatives which can irritate some men.
  • The propionate can spike testosterone and oestrogen levels causing issues with side effects.
  • The carrier oil may negatively affect blood lipids unlike enanthate and cypionate.
  • Some men get anxiety on Sustanon that they do not experience with alternatives.

What does Sustanon do to your body?

Sustanon, like all testosterone, has many effects on the body.

  • Increased muscle growth
  • Increased libido (sex drive)
  • Improved erection quality
  • Reduced body fat
  • Increased confidence and assertiveness
  • Increased hair growth
  • Deeper voice

How do I use it?

Sustanon injection is a ‘depot’ injection. This means it is injected deep into a muscle, where it forms a collection or reservoir of the medicine. The testosterone is then gradually released continuously from the reservoir into the bloodstream.

Our doctors usually recommend regular administration to ensure normal, steady blood levels. Injecting with longer intervals can lead to peaks and troughs, with a return of symptoms and increased risk of oestrogen issues.

Good sterile injection practices must be maintained to reduce risk of infection. This includes washing your hands before handling the medication and injecting. See how to inject safely here.

New, sterile syringes and needles should always be used for each injection. Good technique should be used for the injection with care taken to avoid hitting any major arteries, veins and nerves.

Once the area for injection has been sterilised with an alcohol swab and the needle inserted, the plunger should be pulled back or aspirated to check that the needle isn’t in an artery or vein. If blood is pulled back into the syringe the needle should be removed, replaced and another site attempted. If there is no blood on aspiration, the injection may be commenced slowly.

A 25G needle is recommended to allow passing of the viscous oil. The injection is usually not painful.

You should only inject sustanon if it has been prescribed by a doctor for a known medical condition. You can contact us for more information on how to receive a prescription and treatment.

How Often Should I Inject Sustanon?

The manufacturer’s guidelines state that Sustanon should be injected once every 3-4 weeks, using the whole ampoule of 250mg.

However, this way of dosing has been shown to result in a peak of  77.0nmol/l average testosterone levels – more than double the top of the range men usually have. By the end of the third week, the testosterone levels are back down at a very low average testosterone level (8.0nmol/l) which is at a level that causes low testosterone symptoms. 

Clearly this isn’t the best way of taking this medication.

Most specialists now recommend taking a smaller dose once weekly which results in less peaks and troughs in levels and better results. This also means less side effects.


  • Hands should be washed with soap and warm water before preparing for injection.
  • Sustanon injections should only be used by the prescribed user.
  • A new, sterile needle and syringe should be used for each injection.
  • The injection should only be used on an area of skin which has been sterilised before administration.
  • It should only be injected into a muscle belly – not into an artery or vein.
  • The syringe should always be aspirated (the plunger pulled back to see if blood is drawn into the syringe) before the injection. If blood is drawn then the injection process should be stopped.
  • Injections should never be performed through clothing.
  • Injections should be performed on clean, dry, unbroken skin after use of sterile wipes.

How to Get Sustanon:

Sustanon is a controlled drug and can only be prescribed once you have been assessed by a doctor.

You will require two sets of blood test results indicating low testosterone levels and ensuring that you are safe to start treatment.

Anyone taking TRT needs to have frequent blood tests to ensure optimal levels of testosterone, oestrogen and other blood values to make sure you are safe on treatment.

This treatment should only be used by patients who have been assessed by a professional, GMC certified doctor. They should be deemed to have testosterone deficiency and be safe and suitable for this treatment.


If you would like more advice on Sustanon or Testosterone Replacement Therapy, please contact us, to ask any questions you might have about Sustanon, where to get it or the best options for your own treatment.

Who can’t use Sustanon

Whilst Sustanon and testosterone use are very safe when provided in a controlled manner under a specialist, there are some medical conditions that make TRT use riskier.

Here are some of the conditions that may carry more risk to the patient using Sustanon:

Men with certain conditions may not be appropriate for TRT and Sustanon use due to the potential side effects.

  • Men with a family history of the BRCA gene which predisposes them to breast cancer – if oestrogen levels are raised on treatment and not fully controlled then these individuals are more likely to develop breast cancer.


  • Men with heart failure – if oestrogen is raised this can lead to water retention which puts more pressure on the heart and may put these men at greater risk.


  • Men with severe cardiac history – Sustanon can affect the blood lipids which may lead to a slightly increased risk of cardiovascular issues which can exacerbate cardiovascular disease. Men with issues in this department should discuss the treatment carefully with a specialist before commencing.


  • Prostate cancer – whilst Sustanon does not cause prostate cancer the evidence is not clear as to its effect on men with active prostate cancer. Prostate cancer is treated by reducing androgen levels in the body – this means that increasing levels via TRT is not recommended.
Dr Chris Airey

Dr Chris Airey

Medical Director

This article has been medically reviewed for accuracy by Dr Airey on 12th September 2020.

Dr Chris Airey is a fully registered UK doctor with the GMC (General Medical Council) Reference No: 7490533.
He trained at the University Hospital Southampton and graduated as a Doctor with a joint Bachelor of Medicine and a Bachelor of Surgery, plus a Masters in Medical Science, completing his research project in the Medical Neurosciences Department.
He is undertaking a Master of Science course in Endocrinology and is a member of the European Society for Sexual Medicine, and the Androgen Society.
He has personal experience with taking Testosterone Replacement Therapy and is a pioneer in UK treatment protocols for Testosterone Deficiency Syndrome.