This website has been developed by Besins Healthcare (UK) Ltd.

This website has separate sections for healthcare professionals (containing promotional information), and patients who have been prescribed Testogel® (testosterone) 16.2 mg/g gel, within the UK.

Please confirm that:

This website is provided for HCPs in the UK by Besins Healthcare (UK) Ltd.

Talking testosterone
deficiency (TD)

Talking Testosterone Deficiency


TD is the result of disruption at one or more levels of the hypothalamic-pituitary-testicular (HPT) axis.1 Clinically, this can be split into several different types of hypogonadism:

Primary hypogonadism (hypergonadotrophic hypogonadism)

TD caused by testicular failure. This can be due to genetic disease (such as Klinefelter’s syndrome), or damage to the testes (such as injury, infection or radiotherapy/chemotherapy).2

Secondary hypogonadism (hypogonadotrophic hypogonadism)

TD caused by abnormal activity in the pituitary gland or hypothalamus. In secondary hypogonadism, the testicles are healthy but do not function appropriately due to insufficient production of testosterone-stimulating hormones. Several conditions can cause secondary hypogonadism, including:2

  • Pituitary disorders
  • Obesity
  • Type 2 diabetes mellitus (T2DM)
  • Inflammatory diseases
  • Long-term use of opiates
  • Long-term use of medications, such as antipsychotics or anticonvulsants
  • Kallmann’s syndrome
  • And others

Late-onset hypogonadism (LOH)

Testosterone levels can decline as men age, however the development of TD in older men is thought to be linked to the increased prevalence of certain comorbidities. LOH, otherwise known as functional hypogonadism, is used to describe men older than 50 years who express symptoms of TD, with conditions such as obesity and metabolic syndrome, but no classical primary or secondary cause.3

TD can be reversible if the cause can be successfully treated, for example, TD associated with obesity, inflammatory disease, T2DM or metabolic syndrome.4 However, TD caused by irreversible health conditions, such as congenital abnormalities or ageing, may require life-long treatment.5


  1. Traish AM. Adverse health effects of testosterone deficiency (TD) in men. Steroids. 2014;88:106–116.
  2. Khera M, Adaikan G, Buvat J, et al. Diagnosis and Treatment of Testosterone Deficiency: Recommendations From the Fourth International Consultation for Sexual Medicine (ICSM 2015). J Sex Med. 2016;13(12):1787–1804.
  3. Hackett G, Kirby M, Edwards D, et al. British Society for Sexual Medicine Guidelines on Adult Testosterone Deficiency, With Statements for UK Practice. J Sex Med. 2017;14(12):1504–1523.
  4. Araujo AB, Dixon JM, Suarez EA, et al. Clinical review: Endogenous testosterone and mortality in men: a systematic review and meta-analysis. J Clin Endocrinol Metab. 2011;96(10):3007–3019.
  5. Lunenfeld B, Mskhalaya G, Zitzmann M, et al. Recommendations on the diagnosis, treatment and monitoring of hypogonadism in men. Aging Male. 2015;18(1):5–15.

TES/2020/009. April 2021.

Adverse event reporting

Adverse events should be reported. Reporting forms and information can be found at or search for MHRA Yellow Card in the Google Play or Apple App Store. Adverse events should also be reported to Besins Healthcare (UK) Ltd Drug Safety on 0203 862 0920 or Email: