Sex Hormone Binding Globulin (SHBG) Levels
SHBG binds sex hormones and takes them out of circulation. High levels can mask what's really low bioavailable testosterone or estrogen, even when total levels look fine. This is the "hidden half" that standard hormone panels ignore.
What this measures
How your DNA shapes sex hormone binding globulin (shbg) levels.
SHBG is the protein that binds sex hormones (testosterone, estrogen) in circulation — only the unbound (free) fraction is biologically active. The SHBG gene contains variants that shift baseline production. High SHBG ties up more testosterone and estrogen, reducing free hormone available to tissues; low SHBG leaves more free.
Carriers of SHBG rs1799941 and rs12150660 reduced-production variants are associated with lower SHBG levels — and proportionally more free testosterone and estrogen at the same total hormone levels. Carriers of higher-production variants are associated with the opposite pattern. The variant decides whether a "normal total testosterone" actually means normal free testosterone.
Insulin resistance lowers SHBG; weight loss raises it. Liver health affects SHBG production directly. Hormonal contraceptives raise SHBG meaningfully — sometimes enough to halve free testosterone, which explains some of the libido and energy changes reported on oral contraceptives. Thyroid status, alcohol, and certain medications all shift the picture.
A "normal total testosterone" report isn't the same conversation across SHBG variant patterns. Which SHBG variant you carry decides whether free hormone calculations (calculated free testosterone, bioavailable testosterone) matter in interpreting labs — and whether the right intervention is adjusting SHBG or adjusting total hormone production.
Sex Hormone Binding Globulin (SHBG) Levels is one specific finding in this system. Your Genomic Lifestyle Optimization Report shows where your variants place you on the hormone health spectrum — and what you can do about it.
In your report
Where Sex Hormone Binding Globulin (SHBG) Levels lives inside your Genomic Lifestyle Optimization Report.
Sex Hormone Binding Globulin (SHBG) Levels renders as a dark-background card with a color marker calibrated to your specific variants. The card opens with the gene mechanism, shows your result at a glance via that marker, and closes with a practical, mechanism-led recommendation — what to eat, what to time, what cofactors to support.
Want to see what a real Mosaic dark card looks like? Walk through a sample report →
In context
Sex Hormones: the 6-insight cluster.
Sex Hormone Binding Globulin (SHBG) Levels is one finding in a tightly-related cluster. Mosaic sequences the other 5 alongside it so you see the whole biology — not an isolated data point.
- Dihydrotestosterone (DHT) LevelsDHT is the more potent downstream product of testosterone. High converters may see effects on hair loss, prostate health, or skin—and often benefit from DHT-blocking strategies before symptoms become problems. Low converters rarely need to worry about it.
- Estrogen MetabolismYour liver processes estrogen through multiple pathways—some produce protective metabolites, others produce more aggressive ones. This ratio matters for long-term health and explains why some people feel great on the same hormone levels that cause problems for others. Cruciferous vegetables and targeted supplements can shift the balance.
- Estrogen Receptor SensitivitySame estrogen level, dramatically different response. High receptor sensitivity often underlies severe PMS, difficult perimenopause, or intense menopausal symptoms. It's not in your head—it's in your receptors.
- Luteinizing Hormone ProductionLH is the pituitary signal that tells your body to produce testosterone or estrogen. Low pulsatility is a common root cause of low-T symptoms despite "normal" total testosterone—because the signal to produce more never fires strongly enough.
- Testosterone to Estrogen ConversionAromatase enzyme activity determines how much testosterone converts to estrogen. High converters—often signaled by weight around the middle—benefit from natural aromatase inhibitors like zinc, DIM, and weight training. Low converters rarely need to think about it.
Questions people ask
About Sex Hormone Binding Globulin (SHBG) Levels.
- How does my DNA influence sex hormone binding globulin (shbg) levels?
- The DIO2 thyroid-conversion enzyme that turns inactive T4 into active T3. The COMT and CYP1A1 enzymes that move estrogen through Phase I detox. The SHBG variants that bind or release testosterone. The CYP17A1 and HSD3B2 nodes in the steroid synthesis cascade. Your "normal" labs may sit on top of a genome that needs a different intervention.
- What kind of test do I need to see my Sex Hormone Binding Globulin (SHBG) Levels result?
- Whole-genome sequencing at 30× clinical depth. Consumer SNP-chip tests like 23andMe or AncestryDNA only read ~0.02% of your DNA and miss most of the variants this analysis needs. Mosaic reads all 3 billion base pairs and produces the full 108-insight report.
- How is Sex Hormone Binding Globulin (SHBG) Levels different from clinical lab testing?
- Clinical labs measure downstream biomarkers — blood levels, hormone values, metabolic byproducts — at a single point in time. Genomic insights like Sex Hormone Binding Globulin (SHBG) Levels reveal the underlying variant that shapes the biology, which is constant for life. The two are complementary: labs show the current snapshot; genomics shows the long-term tendency and where lifestyle leverage is highest.
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