Additional Resources:

American Urological Associated Guidelines:

https://www.auanet.org/guidelines/testosterone-deficiency-guideline

 

Endocrine Society Guidelines:

https://academic.oup.com/jcem/article/103/5/1715/4939465

 

Guideline of guidelines: testosterone therapy for testosterone deficiency

https://onlinelibrary.wiley.com/doi/full/10.1111/bju.14899

 

Evolution of Guidelines for Testosterone Replacement Therapy

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6462962/

 Testosterone: why defining a ‘normal’ level is hard to do

http://theconversation.com/testosterone-why-defining-a-normal-level-is-hard-to-do-113587

 A population-level decline in serum testosterone levels in American men

https://www.ncbi.nlm.nih.gov/pubmed/17062768

 Low Free Testosterone Is Associated with Hypogonadal Signs and Symptoms in Men with Normal Total Testosterone

https://academic.oup.com/jcem/article/101/7/2647/2810108