Dear Friend, Testosterone hormone is the male sex hormone. It is also present in females to a small extent. The hormone is present in blood in 2 forms, protein bound and free. About two thirds of the hormone, is found bound to sex hormone binding globulin (SHBG). A little less than one third is bound to protein albumin, while a very small percent, less than 4% is in circulates in free form. The latter two are collectively known as bioavailable testosterone. In most cases, it is advisable to do a total testosterone level. But in certain cases, where the level of SHBG is low, the level of free or bioavailable testosretone is indicated. Depending on the reason fro the test, you should check with your medical consultant for clarity on which test to be done. - Varad Sexology Clinic (Pune)

Hello If there is some problem than go for both total and free testosterone. If the purpose is only screening than total testosterone level is sufficient. And give sample early morning for correct interpretation.