Testosterone, Free (Direct), Serum With Total Testosterone - (LABCORP)
Evaluate hirsutism and masculinization in women; evaluate testicular function in clinical states where the testosterone binding proteins may be altered (obesity, cirrhosis, thyroid disorders).
Use of synthetic steroids, various supplements and/or high doses of biotin may interfere with the accuracy of the standard immunoassay Testosterone Total serum test. If you are taking any of these it is recommended that you order the Testosterone, Total, Women, Children, and Hypogonadal Males, LC/MS-MS for testing.
A significant deviation from the normal range may require further evaluation by your physician.
Free Testosterone (Direct)
Note: If total testosterone results are expected to be >1500 it is best that the Testosterone LC/MS-MS version of this test be ordered.
The highest value on the Free (Direct)Testosterone is >50.
If using a testosterone cream please be sure you have not rubbed any into the antecubital area of your arm for the last 24 hours as it can give elevated results. This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H or coenzyme R). It is recommended to stop biotin consumption at least 72 hours prior to the collection of specimen.