A single fasting growth hormone (GH) level is of limited value. The secretion of GH is episodic and pulsatile. GH has a half-life of 20 to 25 minutes. Testing for growth hormone deficiency or excess is best done as part of a dynamic test involving specific stimuli (see the online Endocrine Appendices: Growth Hormone Stimulation and Growth Hormone Suppression). Insulin-like growth factor-1 can also be useful in assessing growth hormone status.

Insulin-like Growth Factor 1, also known as IGF-1, is used as a biomarker for blood levels of human growth hormone. It is a hormone produced by the liver and other tissues which affects growth-promoting activities and glucose metabolism. The blood level of IGF-1 appears to fluctuate over 24 hours and is found to be related to growth hormone secretion.

This lab test panel includes main blood test makers involved in hair loss in women and men: Complete Blood Count (CBC)- Can detect potential low hemoglobin and infections that can lead to hair loss. Ferritin- Low ferritin, an iron storage protein, has been linked to hair loss and slow down of hair growth. Iron and Total Iron Capacity (TIBC)- Low iron anemia has been linked to hair loss.  Hyperandrogenism: Excessive male hormones (androgens): Total Testosterone (LC/MS), Free Testosterone (Equilibrium Ultrafiltration), DHEA-S, Dihydrotestosterone (DHT)  Hypothyroidism and Hyperthyroidism: Thyroid Stimulation Hormone (TSH), Free Triidothyronine (Free T3)

Approximately 95% of IGF-1 and IGF-II are bound to IGFBP-3, which makes this protein the major carrier of the insulin-like growth factors in circulation. The function of the binding protein is to extend the half-life of the growth factors in the circulation.