Shows the testosterone your body can actually use, helpful when total levels seem unclear.
Bioavailable testosterone is the portion of testosterone that your tissues can actually use. It includes free testosterone plus the part loosely bound to albumin, which can come off easily. It is a calculated value.
It is worked out from total testosterone, SHBG (sex hormone binding globulin), and albumin. This captures the active fraction better than total testosterone when binding proteins are unusual.
Most testosterone in the blood is tightly bound to SHBG and not available to tissues. When SHBG is high or low, total testosterone can be misleading, so the bioavailable fraction gives a clearer picture of androgen activity.
It is useful when symptoms of low or high testosterone do not match the total level, for example in older age, obesity, or thyroid and liver conditions that change SHBG.
Aniva reads your result against research-backed ranges, not just the lab's wide normal. The reference shown below is specific to this biomarker.
Typical adult male guidance, assay and calculation dependent:
| Result | Range |
|---|---|
| Bioavailable testosterone (men) | 2.5 to 11 nmol/L |
Ranges differ by lab and calculation method and are much lower in women. Read your result against the local interval and your symptoms.
As a calculated value, it depends on the accuracy of total testosterone, SHBG, and albumin. Testosterone is highest in the morning and varies day to day. Illness, obesity, and thyroid or liver conditions shift SHBG and the result.
Read alongside total testosterone, SHBG, albumin, and the free testosterone index.
What does a result mean in plain terms? It estimates the testosterone your body can use. High or low results should be read with your symptoms and related tests.
Do I need to fast? No. A morning sample is best, and avoiding heavy exercise and high-dose biotin beforehand helps.
What can affect my result? Time of day, illness, alcohol, and hard workouts can shift levels. Medicines and hormones can change SHBG, which changes this value.
How often should I test? If results are borderline, repeat on a different morning. If you start or change therapy, your clinician may recheck within weeks to months.
How long do results take? Results are usually ready in about 7 days.
What should I discuss with my clinician? Your symptoms, all medicines and supplements, and whether to check total testosterone, SHBG, and other hormones.
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