Factors Affecting Testosterone Levels in Men

The following outlines a number of factors to consider with regards to declining testosterone levels:


Produced from cholesterol, DHEA is a hormone which follows one of two pathways. This two-step conversion will either yield oestrogen’s or testosterone.


The aromatase enzyme is one of the leading factors affecting testosterone levels and the ratio of oestrogen to testosterone.  Aromatase turns testosterone into oestrogen. Depleting free testosterone levels the aromatase enzyme then increases oestrogen.


Obesity suppresses the action of luteinizing hormone (LH) in the testes. This can significantly reduce circulating testosterone levels (Mah and Wittert 2010). This is true even for men under 40.(Goncharov et al. 2009). An increase in belly fat mass has been linked up to increased aromatase levels (Kalyani and Dobs 2007).


Sex hormone-binding globulin (SHBG): Most testosterone that is circulating in the bloodstream will be bound to either sex hormone-binding globulin (SHBG) (60%) or albumin (38%). A minute fraction (2%) is unbound, or “free”. (Morales et al. 2010).

testosterone levels


Testosterone binds more tightly to SHBG than it does to albumin (Henry et al. 2002). Therefore, only albumin-bound testosterone, as well as free testosterone, constitute the bioavailable forms of testosterone. (Morales et al. 2010). The bioavailability of testosterone is influenced by SHBG levels.


Ageing men experienced increased aromatase activity and elevated SHBG production. The result is an increase in the ratio of oestrogen to testosterone as well as the significant  decrease in total and free testosterone levels which causes sarcopenia. (Lapauw et al. 2008). It is crucial that this ratio is corrected.


The liver has a great responsibility. The liver’s role is to remove excess oestrogen and SHBG from the body. If there is any decrease in liver function the hormonal imbalance can compromise healthy testosterone levels. Ageing males are urged to optimise liver function immediately to prevent further degradation and the rapid deterioration that occurs with Andropause.

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