Hormone Testing

MD Custom Rx entrusts ZRT Laboratory for their testing services for sex steroid hormone, cortisol, thyroid levels and more.

ZRT Laboratory is headquartered in Portland, Oregon, ZRT is the recognized innovator of saliva, dried blood spot, and dried urine testing methodologies. ZRT has tested over 2 million people, and currently performs testing for over 4,000 healthcare providers in 26 countries and all 50 states. ZRT is also engaged in ongoing collaborative clinical research with investigators around the world, including the CDC, NIH and prominent universities.

Saliva Testing

Convenient home collection, accurate, and inexpensive, Saliva Testing provides a true picture of the bioavailable levels of steroid hormones.

Saliva testing is a convenient, inexpensive, and above all, accurate means of testing steroid hormones. Scientific studies have shown a strong correlation between steroid hormone levels in saliva and the amount of hormone in the blood that is active or “bioavailable.” It is this fraction of total hormone that is free to enter the target tissues in the brain, uterus, skin, and breasts. Saliva testing can be done anywhere anytime. Testing that relies on blood draws (which need to be done in an office or lab) makes it harder to obtain samples at specific times (such as in the early morning) or multiple times during the day. In addition, hormones in saliva are exceptionally stable and can be stored at room temperature for up to a week without affecting the accuracy of the result. This offers maximum flexibility in sample collection and shipment.

Hormones tested in the saliva profiles include:

  • Estradiol
  • Progesterone
  • Testosterone
  • DHEA
  • Cortisol

Capillary Blood Spot Testing

Capillary Blood Spot Testing offers easy alternative to venous blood draws in the laboratory or doctor’s office.

Blood Spot testing is the future of hormone testing. The process requires only whole capillary blood from a nearly painless finger prick and several tests can be run from a single sample. Blood spot testing provides results on a par with those from serum tests but without the cost and inconvenience of conventional blood drawing. In addition, collection times can be optimized for fasting baseline hormone levels and assessment of HRT dosing and diurnal hormone testing.

Tests offered in the Blood Spot Profiles include:

  • Thyroxine (T4), free
  • Triiodothyronine (T3), free
  • Thyroid Stimulating Hormone (TSH)
  • Thyroid Peroxidase Antibodies (TPO)
  • Testosterone, total
  • Sex Hormone Binding Globulin (SHBG)
  • Prostate Specific Antigen (PSA)
  • Insulin-like Growth Factor (IGF-1)
  • Estradiol (E2)
  • Progesterone (Pg)

Dried Urine Tests

Urine dried on filter paper produces results nearly identical to liquid urine, but has clear advantages in sample transport, size and stability compared to typical 24-hour urine collections. Dried urine tests are also available for steroid hormone metabolites.

Test Blood Spot Saliva Dried Urine
Estradiol (E2)  
Progesterone (Pg)  
Testosterone (T), free    
Testosterone (T), total    
Estriol (E3)    
Estrone (E1)    
Cortisol (C), free    
Cortisol (C), total    
Prostate Specific Antigen (PSA)    
Free Thyroxine (fT4)    
Free Triiodothyronine (fT3)    
Thyroid Stimulating Hormone (TSH)    
Thyroid Peroxidase Hormone (TPOab)    
Thyroxine (T4), total    
IGF-1 (Somatomedin C)    
Luteinizing Hormone (LH)    
Follicle-Stimulating Hormone (FSH)    
Insulin (Ins), fasting    
Cholesterol (CH), total    
HDL Cholesterol (HDL)    
High-Sensitivity C-Reactive Protein (hsCRP)    
Hemoglobin A1c (HbA1c)    
Triglycerides (TG)    
Vitamin D, Total    
25-OH Vitamin D2    
25-OH Vitamin D3    
Iodine (I)    
Bromine (Br)    
Arsenic (As)    
Selenium (Se)    
Cadmium (Cd)    
Mercury (Hg)    
Creatinine (Cr)    

© ZRT Laboratory, LLC. Used with permission.