Bioavailable testosterone blood test
Quick answer: This test estimates the part of testosterone in your blood that the body can readily use. Doctors order it when total testosterone does not match symptoms, such as low energy and low sex drive in men or extra hair growth in women.
- SampleBlood
- TakesAbout 5 minutes
- Before the testAn early-morning sample is usually requested.
- In fertility careTestosterone levels are relevant to sperm production in men and to PCOS in women.
How the test is done
- 1You are usually asked to come in the morning
- 2Blood is drawn from a vein in your arm
- 3The lab measures testosterone and the proteins that carry it
- 4Bioavailable testosterone is worked out from these results
What your results can mean
Reading your report
Hormone ranges differ between labs and by age, sex and cycle day, so discuss your result with your doctor.
If the result is outside the usual range
A low level in men can be seen with testicular or pituitary problems, obesity, or long-term illness. A high level in women can be seen with PCOS or other causes of high androgens.
Who usually has this test
Men with low sex drive, erection problems or low energy, and women with signs of high androgens, especially when total testosterone does not match symptoms.
Risks and aftercare
Minor bruising at the needle site is the only usual effect.
Names and options
Also called: bioavailable T
Listed by the hospital as
- BIOAVAILABLE TESTOSTERONE
Questions about this test
How is bioavailable testosterone different from free testosterone?
Free testosterone is the unbound part only. Bioavailable testosterone includes free testosterone plus the part loosely bound to albumin, which the body can also use.
Why is a morning sample needed?
Testosterone is highest in the morning, especially in men. A morning sample makes results comparable.
Can low testosterone affect male fertility?
Hormone imbalances can affect sperm production. Note that taking testosterone can lower sperm production, so men trying for a baby should discuss this with their doctor.
Related tests
Tamara Hospital & IVF Centre, Rajajinagar
34/3, 10th Cross Road, opp. Vardhaka Sardar Patel School, 1st N Block, 2nd Stage, Rajajinagar, Bengaluru 560010
The hospital is open 24 hours. Call before you come to check the timing for your scan or sample collection.
Get directions ↗IVF Pulse fertility care at Tamara Hospital →
Reception
Waiting area
IVF lab
This page explains each test in general terms so you know what to expect. It is not medical advice: your doctor decides which tests you need and what your results mean. Reference ranges differ between laboratories. Updated 4 November 2026.