SHBG Hormone Levels: How Diet, Lifestyle, and Supplements Influence This Overlooked Hormone Marker

If you’ve ever felt like your hormone lab results were “normal,” yet your symptoms—fatigue, acne, low libido, mood swings— screamed otherwise, then you’re not imagining things. One key piece that’s often missing from the reproductive health conversation is SHBG, or sex hormone-binding globulin.

This under-the-radar protein has a powerful impact on how your hormones behave, and it’s time we start paying more attention to it.

What Is SHBG? (and Why It Matters)

SHBG (sex hormone-binding globulin) is a protein made primarily in the liver. Its main job is to bind to sex hormones like estrogen, testosterone, and DHT (dihydrotestosterone) in your bloodstream.

But why does this matter? Because only unbound (or “free”) hormones can actually interact with your cells and have an effect. 

When SHBG levels are too high or too low, it alters how much active hormone is available, which means you might feel “off” or experience hormonal imbalance symptoms even when standard blood work says everything is “within range.”

So if you’ve ever been told your hormone levels are normal, but you still feel tired, irritable, or out of sync, SHBG could be the missing link. For example, both low or elevated SHBG in females can contribute to PCOS symptoms, and high SHBG in males can lead to low libido and loss of muscle mass.

SHBG has other jobs, too, including helping to regulate how much free testosterone and estrogen your body has at any given time. It acts as a buffering system, keeping hormone levels from swinging too wildly in either direction (too high or too low).

Additionally, SHBG influences hormone-sensitive conditions like PCOS, infertility, acne, low libido, and fatigue. How so? Let's look more closely at how high and low levels of SHBG can contribute to these hormonal issues.

High SHBG vs. Low SHBG: What It Means for Your Health

When SHBG levels are too high, it can bind up excess free testosterone and estrogen¹, making them less available for the body to use. This can lead to symptoms like a lack of sex drive, fatigue, irregular menstrual cycles, erectile dysfunction in men, and difficulty building muscle or losing weight. 

Conversely, when SHBG is too low, it can result in too much free hormone circulating in the body, which may worsen acne, oily skin, and signs of androgen excess like facial hair or hair thinning. 

Because of its tight relationship with sex hormones, SHBG is often tested alongside testosterone and estrogen to better understand the root of hormone-related symptoms.

High SHBG:

SHBG levels being elevated means that more of your hormones are bound and inactive. This results in lower free hormone levels, even if total levels look fine.

High SHBG symptoms may include:

• Low libido or sexual dysfunction
• Fatigue, brain fog, or lack of motivation
• Trouble building muscle
• Depression or low mood
• Fertility issues in both men and women

Elevated SHBG causes can include:

• Estrogen therapy (oral forms especially)
• Hyperthyroidism or overmedication with thyroid hormone
• Liver conditions or chronic inflammation
• Anorexia or undereating
• Certain medications like birth control pills, anticonvulsants, and HIV medications

Low SHBG:

Low SHBG (when sex hormone binding globulin is suppressed) means more hormones are left unbound. This can sometimes lead to excess free androgens like testosterone or DHT.

Low SHBG symptoms may include:

• Hormonal acne or oily skin
• Hair loss or facial hair growth (in women, also called hirsutism)
• Irregular periods or skipped periods
• Polycystic ovary syndrome (PCOS) symptoms
• Trouble getting pregnant
• Insulin resistance, prediabetes, or weight gain
• Mood swings or aggression (in men or women)

Causes of low SHBG include:

• Insulin resistance and high blood sugar
• Obesity
• Hypothyroidism
• Androgenic medications (like the use of anabolic steroids)
• Inflammatory conditions or liver disease

Related: Symptoms of High or Low SHBG Levels, and How to Change It

How Abnormal SHBG Affects Women Vs. Men

SHBG has the job of regulating hormone availability in both men and women, but the effects of abnormal levels can look quite different depending on someone's sex.

In women, low SHBG often means more free testosterone circulating in the body. This can lead to hormone-related symptoms like:

• Acne and oily skin
• Facial hair growth (hirsutism)
• Irregular or absent menstrual cycles
• PCOS symptoms
• Difficulty getting pregnant

On the other hand, high SHBG in women may bind up too much estrogen and testosterone, which can result in low testosterone and decreased libido, fatigue or brain fog, dry skin and vaginal dryness, and decreased bone density over time.

In men, the most common concern is high SHBG², which binds up free testosterone and can cause:

• Low sex drive and erectile dysfunction
• Loss of strength or lean muscle mass
• Mood issues like depression or irritability
• Reduced stamina and motivation

Low SHBG in men is less common but can lead to excess free androgens, possibly increasing the risk of insulin resistance, metabolic syndrome, and prostate issues.

Related: High Testosterone in Women: Common Symptoms & How to Lower It.

Why is SHBG Often Overlooked or Missed?

SHBG isn’t usually included in standard hormone panels unless specifically ordered. Unfortunately, this is a missed opportunity because understanding SHBG levels can explain why you’re experiencing hormonal symptoms despite “normal” total hormone levels. 

Always ask your provider to test SHBG serum levels along with total and free testosterone, estradiol, DHEA, and thyroid markers. Including SHBG in your hormone tests will give you a clearer picture of what's going on with key hormones, including estrogen and testosterone.

How Diet Impacts SHBG Levels

What you eat (or don't eat) can influence your SHBG levels in major ways, especially through its effects on insulin regulation and liver function.

Here’s how dietary choices can impact SHBG:

• High insulin lowers SHBG: Chronically elevated insulin, such as from eating excess refined carbs or sugar, suppresses SHBG production by the liver. A better way to manage insulin is to eat a high-protein diet that includes plenty of fiber and healthy fats. Some people may also benefit from eating a lower-carb diet, such as those with PCOS or insulin resistance. 

• Refined carbs and sugary foods: These spike blood sugar and insulin, which can contribute to low SHBG and symptoms of androgen excess. Eating these foods frequently can also promote fat storage and inflammation, which further disrupts hormonal balance. Over time, this pattern may contribute to conditions like PCOS or metabolic syndrome.

• Fiber-rich foods: Soluble fiber helps support liver health, hormone detox, and more stable blood sugar, all of which benefit SHBG. Foods like oats, apples, seeds, leafy greens, and legumes promote healthy gut bacteria, which also play a role in estrogen metabolism. A fiber-rich diet is also linked to improved insulin sensitivity and support for healthy weight management.

• Cruciferous vegetables: Broccoli, cauliflower, kale, and Brussels sprouts support estrogen metabolism and may help balance SHBG. They’re rich in compounds like indole-3-carbinol, which aid the liver in breaking down excess hormones.

• Phytoestrogens: Found in flaxseeds, legumes, and soy, these can support healthy estrogen activity and indirectly affect SHBG. These plant compounds can gently mimic estrogen in the body, helping to balance hormonal fluctuations. For some people, especially women in perimenopause, this may help improve SHBG and ease symptoms like hot flashes or low libido.

• Alcohol: Excess alcohol stresses the liver and may reduce SHBG production over time. Since SHBG is made in the liver, any damage or burden on this organ can impair its ability to regulate hormone-binding proteins. Regular heavy drinking is also linked to increased estrogen dominance and hormonal imbalances in both sexes.

Related: Best Diet for PCOS.

Supplements That May Support Healthy SHBG Levels

• Myo-inositol and D-chiro inositol: These compounds can help improve insulin sensitivity and ovarian function³, especially in PCOS. By reducing circulating insulin levels, a known suppressor of SHBG, inositols—available in my Myo Inositol Plus formula—can help raise SHBG naturally while also promoting regular ovulation and managing PCOS symptoms⁴.

• Omega-3 fatty acids: These healthy fats have anti-inflammatory effects⁵ and can support liver function. Since SHBG is produced in the liver, improving liver health through omega-3s may enhance its production and support a more balanced hormone profile. Studies⁶ also show that omega-3 supplementation can help reduce serum concentrations of testosterone and regulate menstrual cycles in women with PCOS. Look for a high quality fish oil, such as Omega Plus, to support your hormone needs.

• Vitamin D: Low vitamin D levels are linked to lower SHBG⁷ and lower testosterone in men⁸. Vitamin D supplementation, such as my Vitamin D3/K2 drops, can help support hormone balance by boosting SHBG production and improving insulin sensitivity, particularly in women with PCOS or metabolic concerns.

• Zinc and magnesium: These minerals are important for androgen metabolism and may help normalize SHBG. Zinc plays a role in regulating testosterone levels and is shown to influence SHBG⁹, while magnesium (available in my Magnesium Plus supplement) supports glucose metabolism¹⁰ and reduces systemic inflammation, both of which influence SHBG levels.

• Spearmint tea: Spearmint has been shown to lower free testosterone in women and can help support SHBG. Regular consumption has been linked to increased SHBG levels and improvement in symptoms like weight gain, insulin resistance¹¹, acne, and hirsutism associated with high androgens or PCOS¹².

• Saw Palmetto: Saw Palmetto is useful for androgen dominance¹³ and DHT-driven symptoms. In supplement form, such as Saw Palmetto Plus, it supports the body in balancing testosterone and DHT, which may reduce the androgen load and allow SHBG levels to stabilize.

• Ashwagandha: As an adaptogen, this herb helps regulate cortisol¹⁴ and stress responses, which indirectly supports SHBG production. Chronic stress and high cortisol can suppress SHBG, so ashwagandha’s calming effect on the HPA axis can support relaxation, sleep, libido¹⁵, and overall hormonal harmony.

Related: 
10 Best Supplements for PCOS
Why Inositol Should be Part of Your Plan for PCOS.

Lifestyle Factors That Influence SHBG

• Body Composition: Higher body fat, especially visceral fat (around the belly/abdomen), lowers SHBG and promotes insulin resistance¹⁶. Gaining lean muscle through strength training can improve insulin sensitivity and support SHBG. On the other hand, too low a body fat, such as from crash dieting and over-exercising, can disrupt SHBG and hormone balance.

• Exercise: Regular, moderate exercise can help increase SHBG by improving insulin sensitivity. However, overtraining and extreme exercise without adequate recovery or a balanced diet can raise cortisol, which lowers SHBG.

• Stress and high cortisol: Chronic stress elevates cortisol levels, which suppress SHBG production. Stress management techniques like yoga, breathwork, and journaling may support SHBG indirectly.

• Sleep: Poor sleep affects hormone production, increases cortisol, and can lower SHBG. Aim for 7–9 hours of quality sleep to support hormone and SHBG balance.

Related: PCOS, Inflammation, and Insulin

Medical Considerations & When to Test SHBG

While I recommend asking your provider to include SHBG in hormone tests, testing your levels 

(via a blood test for sex hormone binding globulin and other hormones) becomes particularly useful if you're experiencing symptoms or conditions like:

• Low libido or sexual dysfunction
• Irregular or painful periods
• Fertility struggles
• Fatigue and low energy despite normal labs
• Signs of androgen excess (acne, hair loss, unwanted hair growth)
• Estrogen deficiency symptoms
• Thyroid issues (especially if on medication)

Best practices for SHBG blood work testing:

• Test in the morning, when hormone levels are most stable.
• Ideally, test while fasting, to see insulin and glucose interactions.
• Pair with total and free testosterone, estradiol, DHEA, insulin, glucose, TSH, free T3, and free T4.

Keep in mind that SHBG interacts with some medications, so discuss these with your provider if you're experiencing symptoms of hormonal imbalance. Medications that can interfere with normal SHBG include:

• Thyroid hormones: Hypothyroidism lowers SHBG; hyperthyroidism raises it.
• Estrogen therapy: Especially oral estrogen can increase SHBG dramatically.
• Anabolic steroids

Related: What is the Best Time to Test Hormones?

Key Takeaways on SHBG and Your Hormones

• SHBG determines how much of your hormones are actually active and available to your cells.
• Symptoms like fatigue, mood swings, acne, or irregular cycles could stem from imbalanced SHBG levels, even when other hormones look normal.
• SHBG is deeply influenced by blood sugar, liver health, stress, sleep, and body composition.
• Diet, movement, and supplements can all help regulate SHBG naturally.
• Consider asking for SHBG blood work alongside your routine hormone testing if you're dealing with unresolved hormone symptoms.

References

1. https://medlineplus.gov/lab-tests/shbg-blood-test/ ↩︎
2. https://www.urmc.rochester.edu/encyclopedia/content?ContentTypeID=167&ContentID=shbg_blood ↩︎
3. https://pubmed.ncbi.nlm.nih.gov/30756365/ ↩︎
4. https://pubmed.ncbi.nlm.nih.gov/35477841/ ↩︎
5. https://pmc.ncbi.nlm.nih.gov/articles/PMC8260291/ ↩︎
6. https://pubmed.ncbi.nlm.nih.gov/24639805/ ↩︎
7. https://pmc.ncbi.nlm.nih.gov/articles/PMC5218632/ ↩︎
8. https://pmc.ncbi.nlm.nih.gov/articles/PMC10518189 ↩︎
9. https://pubmed.ncbi.nlm.nih.gov/36171898/ ↩︎
10. https://pubmed.ncbi.nlm.nih.gov/34836329/ ↩︎
11. https://e-cnr.org/DOIx.php?id=10.7762/cnr.2024.13.3.201 ↩︎
12. https://pmc.ncbi.nlm.nih.gov/articles/PMC8710535/ ↩︎
13. https://pubmed.ncbi.nlm.nih.gov/34161166/ ↩︎
14. https://pubmed.ncbi.nlm.nih.gov/31517876/ ↩︎
15. https://pubmed.ncbi.nlm.nih.gov/35873404/ ↩︎
16. https://pubmed.ncbi.nlm.nih.gov/29139641/ ↩︎