Testosterone decanoate

Table of contents

• What is testosterone decanoate?
• How does testosterone decanoate work?
• Which conditions is it used or studied for?
• How is testosterone decanoate given?
• What do the clinical trials show?
• What side effects are known?

What is testosterone decanoate?

Testosterone decanoate is an esterified form of testosterone, the main male sex hormone. In the registered trial it appears as part of Sustanon 250, a solution for injection that also contains testosterone isocaproate, testosterone phenylpropionate and testosterone propionate.^[1] The product is authorised as a medicine in Belgium under authorisation record BE012704, held by Aspen Pharma Trading Limited.^[1] Testosterone itself is classified under ATC code G03BA03, the group for 3-oxoandrosten-4-ene derivatives used as androgens.^[3]

How does testosterone decanoate work?

Testosterone is the principal androgen hormone in men. It binds to androgen receptors in many tissues and supports the development and maintenance of male characteristics, muscle strength, bone density and red blood cell production. In men with androgen deficiency, replacing testosterone aims to restore these functions. The decanoate ester slows the release of testosterone from the injection site, which prolongs its action in the body. The shared care protocol for testosterone in male hypogonadism describes monitoring of testosterone levels, full blood count, liver function tests, lipid profile and, in men aged 40 and over, prostate-specific antigen (PSA).^[2]

Which conditions is it used or studied for?

• Androgen deficiency — a condition in which the body does not produce enough testosterone; the registered trial studies testosterone supplementation in this setting.^[1]
• Palliative care — the trial focuses on male patients in best supportive care who have no therapeutic options left and do not wish to be resuscitated.^[1]
• Male hypogonadism — a shared care protocol covers testosterone treatment for adult men with this condition.^[2]
• Transgender hormone treatment — NHS formulary guidance commissions testosterone for transgender patients requiring virilising endocrine therapy.^[4]

How is testosterone decanoate given?

In the registered trial, Sustanon 250 is given as a solution for injection by intravenous use.^[1] Other testosterone formulations exist, including a 200 mg prolonged-release subcutaneous implant^[3] and transdermal gels such as Testavan and Testogel.^[4] The NHS formulary also lists testosterone injection (Sustanon 250) for male androgen deficiency in adults and advises referring to the summary of product characteristics for full prescribing information.^[4]

What do the clinical trials show?

One registered trial investigates testosterone decanoate as part of Sustanon 250. The trial is a Phase 2 interventional study with a planned enrolment of 25 participants and is currently authorised.^[1] It evaluates the impact of testosterone supplementation on quality of life in male patients in best supportive care. The primary outcomes are the best improvement over time in independence using the ADL independence scale — covering personal hygiene, dressing, going to the toilet, locomotion, continence and eating — and the best improvement over time in symptoms measured by the Edmonton Symptom Assessment Scale, including pain, fatigue, sadness, anxiety, drowsiness, appetite, sense of well-being, shortness of breath, bowel movements and strength.^[1]

What side effects are known?

The shared care protocol for testosterone in male hypogonadism asks clinicians to monitor for adverse drug reactions during treatment and to report any abnormalities.^[2] The protocol does not list specific side effects. No other provided source describes side effects of testosterone decanoate in detail.