Thyroxine-binding globulin, TBG

Optimal Result: 14 - 31 ug/ml.

Thyroid-binding globulin (TBG) is produced in the liver and is the primary circulating (transport) protein that binds thyroid hormones3,5,3’-triiodothyronine (T3) and thyroxine (T4) and carries them in the bloodstream (think of it like a taxi cab that shuttles T3 and T4 around the body).

There are 2 other thyroid hormone transport proteins (Transthyretin & serum Albumin), but TBG has the highest affinity (=the degree to which a substance tends to combine with another) for T4 and T3 but is present in the lowest concentration.

Reference Ranges:

Adult Male: 12.7-25.1 mcg/mL
Adult Female 13.5-30.9 mcg/mL

References:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2417873/
https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/thyroxine-binding-globulin

What does it mean if your Thyroxine-binding globulin, TBG result is too low?

Decreased TBG levels may be due to:

Acute illness
Chronic liver disease
Acromegaly (disorder caused by too much growth hormone)
Hyperthyroidism (overactive thyroid)
Malnutrition
Nephrotic syndrome (symptoms that show kidney damage is present)
Stress from surgery
Medications:
- Androgens
- Salicylates
- L-asparaginase
- Large doses of glucocorticoids (Prednison)

What does it mean if your Thyroxine-binding globulin, TBG result is too high?

An increased TBG level may be due to:

Acute intermittent porphyria (a rare metabolic disorder)
Hypothyroidism (underactive thyroid)
Liver disease
Pregnancy (TBG levels normally increased during pregnancy)
Drugs that can cause high TBG levels:
- Oral Contraceptives
- Estrogens
- Tamoxifen
- Methadone
- Heroin
- Perphenazine

Note: TBG levels are normally high in newborns.

IMPROVE YOUR HEALTH WITH PRECISION.

Get a deeper understanding of your blood, urine, and stool test results.

~~$99~~ $79 per year

$6.60 per month billed annually

✓ Instant interpretation
✓ Science-based recommendations
✓ 1500+ lab biomarkers explained
✓ Upload unlimited amount of lab tests
✓ Online support

Essential Plan

✓ Monthly subscription
✓ Instant interpretation
✓ Use the free self-upload form
✓ Additional charge for upload service
✓ 1500+ biomarkers explained
✓ Recommendations
✓ Cancel anytime

Advanced Plan

✓ Yearly subscription
✓ Instant interpretation
✓ We upload five reports for you
✓ Use the free self-upload form
✓ 1500+ biomarkers explained
✓ Nutrition Recommendations
✓ Online support
✓ Cancel anytime

★ Own It For Life ★ premium plan

✓ No subscription
✓ Unlimited access
✓ Unlimited storage
✓ Instant interpretations
✓ We upload ten reports for you
✓ Use the free self-upload form
✓ 1500+ biomarkers explained
✓ Nutrition Recommendations
✓ Dedicated support

We implement proven measures to keep your data safe.

At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.

General Data Protection Regulation (GDPR). HIPAA compliance for healthcare professionals

Navigate to Metabolic Health