Testosterone - Factors that Interfere with

Introduction

This section describes the substances, endogenous chemicals, nutrients, foods, herbs and other factors that interfere with the function or production of Testosterone.

Alkaloids

 Caffeine may decrease free Testosterone levels (in postmenopausal women).  ^[1]

Enzymes

 Aromatase catalyzes the conversion of Testosterone to Estradiol (although some conversion of Testosterone to Estradiol is beneficial, excessive conversion of Testosterone to Estradiol is undesirable).  ^[2]

 Testosterone is converted to Dihydrotestosterone (DHT) by the 5-Alpha Reductase enzyme:

 Approximately 6% - 10% of the male body’s free Testosterone is normally converted to DHT.

Environmental Toxins

 Bisphenol A may lower plasma and testicular Testosterone levels.  ^[3]

 Dioxin may reduce serum Testosterone levels.  ^[4]

Hormones

 Elevated Cortisol levels may inhibit the production of Testosterone.  ^[5]

 Supplemental Melatonin may inhibit the production of Testosterone - although low dosage levels of Melatonin (up to 3 mg per day) do not appear to interfere with Testosterone production.  Conversely, one study has demonstrated that supplemental Melatonin prevents the age-related decline in Testosterone production.  ^[6]

 Supplemental Progesterone may lower endogenous Testosterone production (in men) to levels that prevent the proper maturation of Sperm.  ^[7]

Lipids

 Trans-Fatty Acids may decrease Testosterone levels.  ^[8]

Prescribed Medications

 Exogenous Anabolic-Androgenic Steroids (A-ASs) may inhibit the body's endogenous production of natural Testosterone (via Negative Feedback Mechanism).

 Most Antiandrogens lower plasma Testosterone levels: