5 Supplements that Lower SHBG & Boost Free-T

By Ali Kuoppala | Last reviewed Tue 25 September 2018

Medical Review by Gerardo Sison, PharmD

Sex hormone binding globulin (SHBG) is a glycoprotein produced by the liver to regulate steroid hormones like testosterone (T) and dihydrotestosterone (DHT).

SHBG works by binding into the active free-testosterone molecules, rendering them inactive and unable to bind the androgen receptor sites in the body. In layman terms, it reduces the activity of bodily androgens.

Naturally lowering SHBG levels results in increased free-testosterone levels and increased androgen activity towards receptors, and is considered favorable for those who seek to maximize their natural testosterone production and utilization.

Here are five supplements that can lower SHBG and increase free-testosterone levels:

1. Magnesium

magnesium glycinate shbg lowering supplementEverybody knows magnesium. It’s the mineral commonly used as a supplement and found in nearly all multivitamins (and obviously in many foods).

Magnesium is the primary electrolyte used by virtually all of the bodily cells to create energy in the form of ATP, it also controls more than 300 enzyme functions, improves sleep quality, promotes muscular relaxation, and maintains the natural fluid balance of the body.

It can also increase free-testosterone levels naturally by blocking SHBG levels and “freeing up” already bound testosterone molecules from the glycoprotein.

According to one human study, roughly a gram of magnesium given to athletes results in 24% increase in free-testosterone levels. Optimal magnesium status has also been found to correlate significantly with higher testosterone levels in observational studies (study, study).

2. Stinging Nettle Root

stinging nettle root shbg levelsStinging nettle root (Urtica dioica), is the stingy (duh) plant found in many guys backyards.

It contains ligand compounds at high levels which have been found in test-tube studies to effectively free up testosterone and DHT molecules from SHBG.

So theoretically stinging nettle root supplements could reduce the binding affinity of SHBG and increase androgen activity of the body (more free T and DHT)…

…But when it comes to actual human research, 120mg’s of nettle root extract taken 3-times per day failed to influence serum testosterone levels, and was only found to marginally increase testosterone levels in rodents via 5 alpha-reductase inhibition (by reducing the testosterone conversion to DHT, exactly what you don’t want as a man).

Bottom line of stinging nettle root is that it should theoretically block the binding affinity of SHBG towards androgens, but still actual human in-vivo studies have found it to not be really effective at increasing androgen levels. Perhaps the active ingredients never make it to the blood-stream when its taken orally?

3. Tongkat Ali

Tongkat ali shbg lowering supplementTongkat Ali (Pasak Bumi), is an Indonesian herb commonly known also by the name “Long Jack”.

It was originally manufactured as an extract in Sumatra (and still you can get the original stuff from there), but many other supplement companies worldwide also currently carry it in their repertoire.

So what does it do to SHBG levels? 

According to multiple citations made by Talbott et al. in their study of Tongkat Ali, the stuff would be very potent at increasing free testosterone levels via SHBG reduction. The thing is that these studies are mostly done by a man named Dr. Tambi, and they are reportedly only presented in conferences, and never made publicly available, so they are to be taken with a grain of salt. Regardless, few other studies have found that Tongkat Ali extract can in fact increase testosterone levels.

I have tried several different brands of Tongkat Ali, but the only one where I noticed a difference was when I finally tested the original 1:200 extract from the Sumatra Pasak Bumi company (affiliate link). Their product was also noticeably more bitter and the powder inside the capsules was darker than the other brands.

4. Boron

Micronutrients categoryWe here at Anabolic Men are big fans of boron.

It simply doesn’t get the attention it deserves, as being potentially the best and most researched trace mineral in increasing testosterone levels.

Here’s what I’m talking about;

So why does boron increase free-testosterone levels so reliably and effectively? Because (drum-roll), it significantly lowers the levels of SHBG.

5. Vitamin D

vitamin d shbgVitamin D is actually a steroid hormone, mistakenly named vitamin.

I don’t really need to buff up its benefits here since everyone and their dogs know how many benefits it has for bone health, immunity, and cardiovascular system.

But what isn’t often talked about is the anabolic side of vitamin D. Research has shown that the vitamin (sorry, hormone) beneficially impacts androgen production in men.

For one, deficiency in vitamin D has been shown to cause significant elevations in SHBG levels and thus, lowered levels of free-testosterone (study, study, study).

Also, long-term supplementation (1-year) with 3332 IU of vitamin D3 resulted in average increase of 25.2% in total testosterone levels and 20% increase in free-testosterone levels of healthy men when compared to placebo.

I get almost all of my micronutrient supplements from Thorne Research, including the vitamin D3 liquid (affiliate link). You can also apply it topically to the skin for better absorption.


SHBG binds to free-testosterone and free-DHT, rendering them inactive.

There are many natural methods to suppress SHBG levels, resulting in higher free-testosterone and DHT levels. Vitamin D, boron, magnesium, Tongkat Ali, and stinging nettle root are good examples of supplements that can do this.

Here are the clinically proven daily dosages for each of the five;

  • Boron – 10-12mg
  • Magnesium – 1000mg
  • Nettle root – unknown
  • Vitamin D3 – 4000IU
  • Tongkat Ali – 300mg of 1:200 extract

Are there any other natural ways to lower SHBG? Yes, eating more carbs (especially the naturally occurring fructose in fruits), lowering alcohol intake, eating less fiber, etc.

Ali Kuoppala

Ali Kuoppala is the founder of Anabolic Men. He has authored and co-authored multiple men's health books and focuses on uncovering the methods of optimizing hormonal health. To date, his articles on various websites have been read more than 15-million times. To read more about Ali, visit his Medium article.