What is SHBG?
SHBG
SHBG (sex hormone-binding globulin) is a protein that binds testosterone and other sex hormones, affecting the amount of free, active hormone in the body. The material tracks how SHBG levels are influenced by diet, medications, and hormone therapy, and how these changes impact free testosterone.
How it developed
- Sep 2025 - Derek said that on a ketogenic diet, SHBG levels can be “through the roof” and free testosterone much lower.
- Sep 2025 - Derek noted that in a trial using AndroGel to raise total testosterone from hypogonadal to around 400, the results may not reflect what many men experience with injectable testosterone boosting total T to 1,000.
- Sep 2025 - Derek stated that the quantity that moves SHBG meaningfully is 6 to 12 mg, which can liberate free testosterone rather than increase total testosterone.
- Apr 2026 - A guest said that in women, SHBG goes up when taking oral contraceptives and stays elevated for life if they continue taking them.
In the evidence
Every line below is attributed to a named speaker.
Why the Traverse trial's cardiovascular safety findings for testosterone cannot be generalized: it used Androgel to reach only ~430 ng/dL total testosterone, whereas many TRT patients use injectables that transiently spike to 1000+ ng/dL with disproportionately high free testosterone and suppressed SHBG.
“In that traverse trial using andro gel to bump your total tea from like hypoganatal to like 400 is not necessarily indicative of what I would say a lot of people are looking to the data to see what the results were of testosterone therapy because a lot of guys are on injectable test boosting to 1,000 total tea with a disproportionately high free testosterone cuz when you inject infrequently too you drive your SHBG that is not the same as a guy who's using an androgel to get to like 430 total T. So taking that outcome and running with it as like no cardiovascular risk like I think it's a bit haphazard personally.”Derek · 9 Sep 2025
Why ketogenic and carnivore diets can cause borderline hypogonadal free testosterone: the absence of insulin signaling fails to suppress SHBG, binding more testosterone and reducing the free fraction despite normal total testosterone.
“If you're on a ketogenic diet, you can absolutely expect your SHBG levels to be through the roof and your free test to be much lower.”Derek · 9 Sep 2025
Oral contraceptives raise SHBG permanently. Elevated levels persist for life even after a woman stops taking the pill.
“In women, SHBG goes up when you take oral contraceptives and it stays up for life if you take oral contraceptives.”
Boron at 6 to 12 mg per day as a low-cost SHBG-lowering supplement that increases free testosterone without raising total testosterone production, worth tracking for men with high SHBG.
“The quantity that moves the needle for SHBG I believe was like 6 to 12 milligs and can be meaningful for actually liberating free testosterone not for actually producing more total tea.”Derek · 9 Sep 2025