Free Testosterone

Free testosterone is a measurement of testosterone that is not bound to SHBG, and is thought to be more reflective of the effects of testosterone than a basic blood measurement of testosterone.


Research analysis by and verified by the Examine.com Research Team. Last updated on Apr 29, 2017.

Human Effect Matrix

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what supplements affect free testosterone

Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
Notes
Dehydroepiandrosterone
All comparative evidence is now gathered in our ​A-to-Z Supplement Reference.
The evidence for each separate supplement is still freely available ​here.
Zinc  
Chromium  
Nigella sativa  
Velvet Antler  
Vitamin E  
Boron  
Calcium  
D-Aspartic Acid  
Tribulus terrestris  

Cite this page

"Free Testosterone," Examine.com, published on 5 July 2013, last updated on 29 April 2017, https://examine.com/topics/free-testosterone/