Lately, there have been questions about how to lower SHBG (sex hormone binding globulin). Is it even possible to lower SHBG levels with naturally or with supplements? In this article, I try to go through this issue.
What is SHBG (Sex hormone binding globulin) and why it matters?
Sex hormone binding globulin (SHBG) is a glycoprotein produced by the liver. Accordance with its name, SHBG circulates in the blood “binding” hormones flowing out there and suppressing them useless. However, SHBG binds and suppresses estrogen (estradiol) about ten times less effective than it binds androgen. In other words, high levels of SHBG is not a good thing to testosterone. Repeatedly measured high SHBG is usually bad news for a man because it can mean that you might have serious health problems.
The general normal SHBG reference range for males is ~20-60 nmol/L
High-value SHBG 71-120 nmol/l might be caused by the following:
– Liver disease: cirrhosis and fatty liver may increase SHBG levels.
– Too much estradiol in the body.
– Vitamin D, magnesium and zinc deficiency
– HIV infection
At first glance, low SHBG might sound good, because it also means that biologically active free testosterone levels are also high. However, the concern here is that low levels of SHBG might be linked to heart disease and insulin resistance in men.
Low-value SHBG 0-16 nmol/l:
– High biologically active free testosterone levels
– Risk of insulin resistance (source)
– Increased risk of death from cardiovascular disease (source)
Is it possible to lower SHBG levels naturally?
It can be challenging, as there are not really many effective supplements to lower it (clear science-based evidence). Anyway here is a list of nutritional strategies and supplements which have at least some kind an evidence on lowering SHBG levels. This information is meant to be educational, not medical advice. Always consult your doctor first if your shbg levels are out of the normal range.
Common things that might affect SHBG levels
– Too small protein intake might increase your SHBG levels (1, 2). Try upping your protein intake to 1,5-2 grams per bodyweight.
– If you are drinking enough alcohol to ruin your liver it will increase your SHBG levels (1, 2). To drink alcohol more safely check out -> Hangover cures (how to drink without ruining your health)
– Too much caffeinated drinks (+6 cups of coffee, green tea or caffeinated drink) might increase SHBG levels if you believe studies made on pre/postmenopausal womens (1, 2). Anyway 4-5 cups of coffee is the sweet spot for reaping coffee’s health benefits, so no reason to go over board.
– If you have high estrogenic hormones your body will increase SHBG production (1).
Supplements to lower SHBG
Vitamin D – It’s been proven in numerous studies that low vitamin D levels is a guaranteed way to keep your testosterone levels low (1, 2, 3). Low vitamin D levels can also affect your SHBG levels.
Medical University in Austria found that men with more than 30 microg/l of vitamin D in their bloodstream had significantly lower levels of SHBG and higher levels of testosterone, than those lower than 30 microg/l (4).
Fixing Vitamin D deficiency should be every man’s (and women’s) top priority. Firstly I recommend taking the blood test (25(OH)D) to see your vitamin D levels. The blood level of vitamin D should be more than 70 nmol/l (optimal level is closer to 110 nmol/l).
A good rule of thumb for taking vitamin D supplementation, according to Vitamin D council – Take 1000 IU (25 mg) per 10 pounds of your bodyweight. So, if you weight 110 lbs (50kg) is worth of taking 5,000 IU (125mg) per day.
A safe upper limit for adults is 10,000 IU / day. It’s not worth to take more even if you weight more than 100 pounds (unless you know you have deficiency by blood test). After 1-2 months of supplementing vitamin D check your blood levels again and adjust supplement dosage from there. Vitamin D should be taken with your fattiest meal, so it is better absorbed (Vitamin D is fat-soluble vitamin).
Fortunately fixing vitamin D levels is one the easiest and cheapest problems to fix. Just take 10-20 minutes sun almost every day or take vitamin D supplements.
When choosing vitamin D supplements, make sure you get cholecalciferol (vitamin D3) form, which way more potent than D2 (study). It’s also wise to choose supplements where vitamin D is stored with some kind an oil, as vitamin D is fat soluble vitamin (olive oil or MCT-oil). Good guality supplements starts at 3 cents per day. But my personal favorite vitamin D supplements is Thorne’s liquid vitamin D + k2 combo. K2 is important vitamin converted from vitamin K but only if you eat enough dark green vegetables (5). Most people just wont eat enough kale and spinach so supplementing K2 is also vitally important.
Magnesium is one the most important minerals for human endocrine system testosterone levels. However, fewer people know that magnesium might also have suppressing effect for SHBG. Research has shown that magnesium binds to shbg and disturbing its T suppressing effect. Which actually result to improvement in free testosterone levels.
The change in magnesium levels inside the biological serum concentration range (0.75–0.95 mM) could lead to an enhancement of the Bio-T. In fact, the affinity of T to SHBG seems to change slightly with the magnesium concentration. Magnesium binds SHBG in a nonspecific mode, leading to an uncompetitive inhibition with T in binding SHBG and to a subsequent enhancement of Bio-T availability. The binding is accompanied by a magnesium release (or uptake) with a corresponding heat effect around in magnitude 17 kJ/mol – Source
Most people think that they get enough magnesium from their diet, but actually, the truth is quite opposite. It’s estimated that about 46–60% of U.S. population doesn’t get enough magnesium from their diet. Magnesium deficiency is also widespread in Europe. It’s almost impossible to get enough magnesium from today’s foods, even if your diet is perfect.
Video about magnesium deficiency
Which magnesium type to use? Magnesium glycinate – Magnesium mixed with amino acid glycine is one of the best absorbable forms of magnesium. Glycine is one the most widespread amino acid found in the human body and has certain benefits from calming nerves to promoting better sleep. Magnesium glycinate is the best choice for those trying to fix their magnesium deficiency, as its less likely to cause laxative effects with high doses. Magnesium glycinate is also a good choice for those who takes magnesium for better sleep because sleep promoting and calming effects of glycinate. Product I been using: Magnesium Glycinate
Magnesium citrate – Magnesium mixed with citric acid in a 1:1 ratio. Magnesium citrate high doses can cause laxative effects, especially if you take it on empty stomach, thus is recommended to be taken with a meals. Magnesium citrate has good bioavailability and inexpensive, making it good value for money. Personal favorite: Now Foods, Magnesium Citrate (100% powder). Or capsules.
Magnesium oil – Very good for sore muscles and help to recover from hard training. Best results are obtained by rubbing magnesium oil to skin and leave it on for at least 15min. I recommend Life Flo Magnesium oil.
Nettle root (Urtica dioica is better know by its ability to reduce symptoms associated with benign prostate hyperplasia (BPH increased prostate). If you are suffering from this problem, just as a pointer, not a medical advice. Nettle root has shown to alleviated symptoms and even reduced size of prostate without side effects in a well-designed double-blind, placebo-controlled study.
Nettle root is also touted to lower shbg levels. Which is at least partially true, as nettle root contains lignans which bind to SHBG, interfering its testosterone and estradiol (E2) hunting.
The problem with this is that nettle root also inhibit an enzyme (5α-reductase) that converts testosterone to DHT-hormone (dihydrotestosterone). Another problem with nettle root is that how you get these lignans to absorb optimally since these lignans are absorbed mainly in the colon.
Peoples experiences with nettle root are quite different. One gets best erections of his life, other feels nothing. Personally I experienced a small rise in sex drive, but as always it could have been just a placebo effect. However nettle root is perfectly safe herb, so I see no reason not to try it (sources:1, 2, 3, 4, 5).
Remember we are talking about nettle root here, not a general stinging nettle leaf supplements. Is the stinging nettle’s root that have these components (lignans that bind to shbg). There are many different forms of nettle root supplements, from powder to alcohol and capsule extracts. Personally I used this nettle root extract 2 capsules daily for similar dosages used in most studies.
Boron is interesting “space trace mineral” (forms from cosmic ray spallation). At the beginning of the 90th century boron was popular testosterone booster among bodybuilders. But after studies demonstrated it to be almost useless, use of boron supplements ceased almost completely. Now as a result of new studies it has come to the surface again, as SHBG lowering supplement and a testosterone booster.
In an older ninety-century study where healthy men took 10mg of boron for 4 weeks showed about 11% increase in testosterone levels but in addition their estradiol rise shocking 42% which is definitely not a good thing.
“Supplementation with 10 mg B/d for 4 wk resulted in 84% of the supplemented dose being recovered in the urine. Plasma estradiol concentrations increased significantly as a result of supplementation (51.9 +/- 21.4 to 73.9 +/- 22.2 pmol/L; p < 0.004) and there was a trend for plasma testosterone levels to be increased" - Study
Another ninety-century study where male bodybuilders were given 2,5 mg boron supplement (probably too small amount for any effect) daily for 7 weeks noted no significant differences in male hormones between placebo group.
“Analysis of variance indicated no significant effect of boron supplementation on any of the dependent variables. Both groups demonstrated significant increases in total testosterone, lean body mass, 1-RM squat, and 1-RM bench press. The findings suggest that 7 weeks of bodybuilding can increase total testosterone, lean body mass, and strength in lesser trained bodybuilders and that boron supplementation had no effect on these measures.” – Study
Lastly there is very convincing never study where 10mg boron every day with breakfast for a week lowered SHBG (-4,7%) and estradiol (-39%) while increasing free testosterone levels (+28) and DHT(+6,7%). Though, this study had small sample size consisting of only 8 people.
Boron in plasma increased significantly following hours and weekly consumption. Six hours supplementation showed a significant decrease on sex hormone binding globulin (SHBG), high sensitive CRP (hsCRP) and TNF-α level. After one week (in samples taken at 8.00 A.M, only), the mean plasma free testosterone increased and the mean plasma estradiol decreased significantly. – Study
According to these studies, dosages close to 10mg of boron daily seems to be the optimum dose for testosterone boost and lowering SHBG levels, while small 2,5mg dose daily did nothing. Studies show mixed results, but again I don’t see a reason not try it. Boron is cheap and perfectly safe supplement up to 20mg daily for adults (1).
There are foods that have boron naturally, but it’s almost impossible to get similar dosages which were used in these studies from food. But generally speaking, you can get your boron daily recommended intake from food. For example foods high in boron: dried fruits (raisins, prunes, apricots), fruits (avocado, red apple), nuts (almonds, hazelnuts, brazil nuts).
Unless you can’t eat 400-500 grams of raisins or other foods high in boron daily, boron supplement is needed to achieve dosages (10mg day) that affect shbg / testosterone levels. For the best bioavailability, it’s good to choose mixed complex of 3 forms of boron (citrate/aspartate/glycinate). I did use this triple boron 3 capsules daily (for a total 9mg boron per day).
There are some herbs and supplements which have some kind an evidence lowering SHBG levels. But first I would suggest to check up with your doctor if you have some health issues that raises your SHBG levels. After that focus on the basics.
General ignorance about men’s health and testosterone can wreck your hormones including SHBG levels. Learn the basics of testosterone and men’s health here. For erection and sex drive keep your estrogen & prolactin low. Afterward, if you still struggle with high SHBG levels and want to lower it, experiment with strategies and supplements mentioned in this article.