A Bioavailable Testosterone blood test measures the amount of testosterone in your body that is not bound to proteins and is therefore available for tissues to use. Unlike total testosterone, it reflects the active hormone influencing energy, muscle strength, mood, and overall wellbeing.

In Australia, this test is an important tool for assessing men’s health, especially when symptoms such as fatigue, low libido, or changes in body composition appear. Understanding your levels can also provide insights into metabolic health, bone density, and long-term vitality.

This guide explains what it is, how it works, what your results mean, and how you can book a comprehensive blood test to check your Bioavailable Testosterone.

What is Bioavailable Testosterone?

Testosterone in your blood exists in two main forms: bound and unbound. Most of it is attached to proteins like SHBG (sex hormone-binding globulin) and albumin, which makes it unavailable for the body’s cells to use. Bioavailable Testosterone is the portion that is free or loosely bound, meaning it can easily enter tissues and do its job.

Think of it like money in your wallet versus money locked in a savings account. Your total testosterone is the full amount you have, but your Bioavailable Testosterone is the cash you can actually spend right away.

This matters because it’s the active form that directly supports your muscles, bones, energy, mood, and reproductive health. Sometimes, total testosterone levels may look normal, but if bioavailable levels are low, symptoms can still appear.

Quick facts:

• Bioavailable Testosterone is the fraction your body can use right away.
• It gives a clearer picture than total testosterone alone.
• Low levels can affect metabolism, mood, strength, and sexual health.

Because of this, doctors often request a Bioavailable Testosterone blood test when symptoms don’t match total testosterone results, making it a more reliable measure of hormonal health.

Why is Bioavailable Testosterone important?

Bioavailable Testosterone is a key hormone for health, longevity, and metabolism. When levels are sufficient, it supports muscle strength, bone density, mood, and energy; when low, it can contribute to several common health issues.

For example, low Bioavailable Testosterone is linked with insulin resistance and an increased risk of type 2 diabetes, elevated body fat (especially around the waist), and reduced muscle mass. It’s also associated with mood disorders (like depression), weaker bones (greater fracture risk), decreased libido, and fatigue. Over time, these issues can reduce life expectancy and lower quality of life.

Some relevant stats:

• A large U.S. study found that higher Bioavailable Testosterone was significantly associated with better processing speed, working memory, and attention in men over age 60.
• Research confirms that Bioavailable Testosterone tends to decline faster than total testosterone as men age, especially after age 30–40, contributing to age-related frailty, sarcopenia (muscle loss), and metabolic slowdown.

Empowered by this knowledge, you can see that measuring Bioavailable Testosterone (not just total testosterone) gives a more accurate picture of hormone function—and helps identify issues early so interventions (lifestyle, medical, nutritional) can be more effective.

When should you get a Bioavailable Testosterone test?

You might consider a Bioavailable Testosterone blood test if you notice certain symptoms or have risk factors that affect hormone balance. Common scenarios include:

• Persistent fatigue, low energy, or reduced motivation
• Decreased muscle mass, strength, or unexplained weight gain
• Reduced libido, erectile difficulties, or fertility concerns
• Mood changes such as irritability, low mood, or brain fog
• Family history of hormonal disorders or early-onset metabolic disease
• Chronic conditions like obesity, diabetes, or metabolic syndrome
• Monitoring during andropause or suspected low testosterone with normal total testosterone
• GP referral when symptoms don’t align with other blood test results

Testing can provide clarity, especially when symptoms persist despite other results appearing normal. It gives a deeper look into your active hormone levels and supports more informed next steps for your health.

How does the Bioavailable Testosterone test work in Australia?

In Australia, a Bioavailable Testosterone blood test is performed through a standard blood draw, usually from a vein in your arm. Most patients don’t need to fast unless the test is part of a larger panel that includes glucose or lipid levels.

Access is typically via two pathways:

• GP referral: If you have symptoms of low testosterone, your doctor can order the test through Medicare. In this case, the cost is generally covered.
• Private testing: If you arrange the test without a referral—for example, as part of a comprehensive hormone or health panel—you’ll usually pay out of pocket. The Bioavailable Testosterone test cost in Australia varies but often falls between $50 and $150 depending on the provider and whether it’s bundled with other markers.

Comprehensive health services also offer panels that check Bioavailable Testosterone alongside more than 50 biomarkers, giving a wider view of metabolic and hormonal health.

This makes it easier for Australians to monitor hormone balance, either through routine medical pathways or private health check providers, ensuring that important issues don’t go undetected.

What do my Bioavailable Testosterone results mean?

Your Bioavailable Testosterone results show how much active testosterone is available in your body. Interpreting these numbers helps explain why you may be experiencing certain symptoms. Low levels can cause fatigue, reduced libido, or mood changes, while higher levels may point to other hormonal imbalances.

Below is a general guide to Bioavailable Testosterone results in nmol/L. Reference ranges can vary slightly between Australian pathology labs, so always discuss your results with your GP or healthcare provider.

If your results are outside the normal range, your doctor may suggest further testing, including related markers such as total testosterone, SHBG, or albumin, to provide a clearer picture of your hormone health.

Bioavailable Testosterone in context with other tests

A Bioavailable Testosterone test is most useful when assessed together with other hormone markers. This is because testosterone in the body exists in different forms, and understanding how they interact provides a clearer picture of your health.

Doctors often review Bioavailable Testosterone alongside:

• Total Testosterone gives the overall hormone level in the blood, including both usable and bound forms.
• SHBG (Sex Hormone-Binding Globulin) shows how much testosterone is tightly bound and therefore unavailable to the body.
• Albumin reflects the portion of testosterone loosely bound to proteins, which can still be used by tissues.
• Other hormones like estradiol, luteinising hormone (LH), and follicle-stimulating hormone (FSH) help assess broader reproductive and metabolic health.

By looking at these tests together, healthcare providers can identify whether symptoms such as low energy, mood changes, or reduced strength are linked to true testosterone deficiency or to imbalances in binding proteins. This combined approach offers a more accurate understanding of hormone activity and supports better treatment decisions.

Lifestyle and practical steps for Bioavailable Testosterone

Everyday habits play an important role in supporting healthy Bioavailable Testosterone levels. While genetics and age influence hormones, lifestyle choices can make a real difference in how your body produces and uses testosterone.

1. Nutrition: A diet rich in whole foods, lean protein, healthy fats, and nutrients like zinc, vitamin D, and magnesium supports testosterone. Highly processed foods and excess alcohol may lower levels over time.
2. Exercise: Regular physical activity, especially resistance training such as weightlifting or bodyweight exercises, helps boost hormone function and maintain muscle mass.
3. Sleep: Getting 7–9 hours of quality rest each night is vital. Even a single week of poor sleep has been shown to reduce testosterone levels.
4. Stress management: Chronic stress raises cortisol, which can suppress testosterone when it remains high. Mindfulness, relaxation techniques, and time outdoors can help bring balance.
5. Overall lifestyle balance: Combining healthy eating, movement, rest, and stress control creates the best foundation for hormonal health and long-term wellbeing.

The best starting point is testing. Once you know your levels, you can take personalised steps.

FAQs about the Bioavailable Testosterone test in Australia

What is a Bioavailable Testosterone test?

It measures the amount of testosterone in your blood that is active and available for your body to use. Unlike total testosterone, it gives a clearer picture of hormone function.

How much does a Bioavailable Testosterone test cost in Australia?

The cost varies between providers, usually ranging from $50 to $150 when paid privately. If ordered by a GP for medical reasons, Medicare may cover the test.

Is the Bioavailable Testosterone test covered by Medicare?

Yes, Medicare can cover the test if your GP refers you due to relevant symptoms or health concerns. Private self-referrals are usually not covered.

Do I need a referral to get tested?

You can access the test through a GP referral, which may reduce costs, or by booking privately with a pathology clinic or health service.

Can women take a Bioavailable Testosterone test?

Yes. While testosterone is often linked to men, women also produce it. Low or high levels can affect fertility, energy, mood, and overall health.

What symptoms suggest I should get tested?

Common symptoms include fatigue, low libido, mood changes, reduced strength, and unexplained weight changes. Testing helps confirm if hormones are playing a role.

What is the normal range for Bioavailable Testosterone?

For men, the typical reference range is about 2.0–6.0 nmol/L, though it may vary by lab. Women generally have much lower levels. Always check results with your GP.

Conclusion

Bioavailable Testosterone is the active portion of testosterone that your body can use to support energy, strength, mood, metabolism, and reproductive health. Unlike total testosterone, it provides a clearer picture of how well your hormones are functioning day to day. Low or high levels can be linked to common concerns such as fatigue, weight changes, reduced libido, or mood imbalances, making this test an important tool for understanding your overall wellbeing.

Testing gives you more than just numbers—it provides knowledge that can guide your next steps. Whether that means adjusting lifestyle habits, exploring further medical advice, or simply gaining peace of mind, knowing your Bioavailable Testosterone levels helps you make informed choices for your health and longevity.

Take control of your health today. Sign up for our comprehensive blood test and get clear insights into your Bioavailable Testosterone and more than 50 other key markers.

References

• RACGP. “Assessment and management of male androgen disorders” (Australian Family Physician)
• PubMed. Associations of Bioavailable Serum Testosterone With Cognitive Performance in Older Men
• PubMed. Bioavailable testosterone and androgen receptor activation with resistance training in pre-menopausal females
• Journal of Clinical Endocrinology & Metabolism. Age-Related Changes in Serum Testosterone and Sex Hormone-Binding Globulin in Australian Populations
• Choosing Wisely Australia