E/A: 5b/5a Ratio (FMV urine, menopause)

An elevated E/A ratio indicates less 5α-reductase activity, which is not thought to be a clinically relevant finding – though physiologically induced 5α-reductase blockade states via pharmaceuticals (such as Finasteride) may be associated with side effects such as impotence, decreased libido, depression and anxiety in men. Robust inhibition of 5α-reductase activity decreases the production of DHT, resulting in increased levels of testosterone - and subsequently estradiol (via aromatization pathways). As a result of increased substrate flow through the aromatization pathways, gynecomastia has also been described in men.

A low E/A ratio indicates more 5a-reductase activity and greater production of DHT from testosterone. 

- Symptoms in a male might include BPH and lower urinary tract symptoms. 
- Symptoms in a female might include hirsutism, acne, infertility, polycystic ovary syndrome (PCOS), and oily skin. 

Both men and women may experience androgenic alopecia as a result of higher DHT production. Therapeutic strategies for 5α-reductase inhibition may be considered, and include pharmaceutical intervention with 5α-reductase inhibitors (such as Finasteride) or botanical inhibitors (such as saw palmetto).

The Etiocholanolone/Androsterone (E/A) Ratio assesses androgen metabolism by comparing the enzymatic activity of 5β-reductase/5α-reductase.