DISCUSSION THREAD - Free vs. Total Testosterone: What’s the difference?
Posted: Fri Apr 23, 2021 9:53 am
In light of the blood test results that we have been posting up, we’d like to discuss a few points that will help you all analyse the results better.
Approximately 98% of the testosterone the body produces is bound to either sex-hormone binding globulin (SHBG), or albumin. This is referred to as “bound testosterone.” The 2% that’s left is known as “free testosterone.”
This unbound or “free” testosterone is what connects with testosterone receptors within the body’s cells. When a cell absorbs free testosterone, it enables its functionality, such as cell replication in the bones and muscles. Free testosterone is also responsible for the creation of what are known as secondary sexual characteristics in men. These include things like facial hair and a deeper voice. As the name suggests, total testosterone is the grand total of all the hormone available in the bloodstream. While some testosterone tests only account for total testosterone, they might not be as helpful as once thought. Here’s why-
A 98% proportion is normal for bound testosterone – but obviously, anomalies can occur. Limiting testing to total testosterone levels overlooks the possibility of excessive bondage to either SHBG or albumin. Here’s why it matters. The possibility of excessive bondage means that it is possible to have normal levels of total testosterone but still have insufficient free testosterone to perform its essential functions. Too little free testosterone can lead to poor muscle development, irritability, lowered sex drive and a host of other issues that one may not readily associate with too little free testosterone.
Therefore, while total testosterone levels may appear healthy, low levels of free testosterone could lead to improper diagnosis and treatment plans. For example, a patient may not need more testosterone. They may simply need less of substances that tend to convert testosterone into other substances such as estrogen. This is why it may be critically important to test for free testosterone levels and not just total testosterone alone.
Bioavailable Testosterone
Until recently, free testosterone was the only type considered biologically active. It turns out, however, that the portion of the hormone bound to serum albumin tends to become available in the capillary bed. Therefore, non-SHBG-bound testosterone is also deemed as “bioavailable.”
One way of looking at bioavailable testosterone is that it is like a reserve supply, ready for use when the body is low on free testosterone. However, scientists still don’t know how much bioavailable testosterone goes on to be absorbed by cells in these conditions. In most cases, bioavailable and free testosterone run even. Exceptions to this are known to manifest due to certain medical conditions and medications. For example, corticosteroids and sex steroids may cause an increase or decrease in SHBG amounts. In such instances, medical professionals may have difficulty properly diagnosing abnormalities. For this reason, it is critical that men disclose to their doctors all the medications they are taking as a part of their consultation. There are also other conditions that may cause diagnostic problems. These include:
1. Genetically caused SHBG-binding abnormalities
2. Liver disease
3. Severe systemic illness
Increasing Free Testosterone Levels There are two ways to improve free testosterone levels. In general, anything that increases total testosterone levels (such as forms of exercise or supplementation) will also elevate free testosterone. The other method involves reducing SHBG bound testosterone.
While the aging process naturally increases SHBG bondage, other factors can accelerate the process. Levels of certain hormones such as insulin, growth hormone, estrogen, and thyroid hormones are known to affect SHBG bonding. Vitamins and herbs, including vitamin D and boron are thought to lower SHBG.
Approximately 98% of the testosterone the body produces is bound to either sex-hormone binding globulin (SHBG), or albumin. This is referred to as “bound testosterone.” The 2% that’s left is known as “free testosterone.”
This unbound or “free” testosterone is what connects with testosterone receptors within the body’s cells. When a cell absorbs free testosterone, it enables its functionality, such as cell replication in the bones and muscles. Free testosterone is also responsible for the creation of what are known as secondary sexual characteristics in men. These include things like facial hair and a deeper voice. As the name suggests, total testosterone is the grand total of all the hormone available in the bloodstream. While some testosterone tests only account for total testosterone, they might not be as helpful as once thought. Here’s why-
A 98% proportion is normal for bound testosterone – but obviously, anomalies can occur. Limiting testing to total testosterone levels overlooks the possibility of excessive bondage to either SHBG or albumin. Here’s why it matters. The possibility of excessive bondage means that it is possible to have normal levels of total testosterone but still have insufficient free testosterone to perform its essential functions. Too little free testosterone can lead to poor muscle development, irritability, lowered sex drive and a host of other issues that one may not readily associate with too little free testosterone.
Therefore, while total testosterone levels may appear healthy, low levels of free testosterone could lead to improper diagnosis and treatment plans. For example, a patient may not need more testosterone. They may simply need less of substances that tend to convert testosterone into other substances such as estrogen. This is why it may be critically important to test for free testosterone levels and not just total testosterone alone.
Bioavailable Testosterone
Until recently, free testosterone was the only type considered biologically active. It turns out, however, that the portion of the hormone bound to serum albumin tends to become available in the capillary bed. Therefore, non-SHBG-bound testosterone is also deemed as “bioavailable.”
One way of looking at bioavailable testosterone is that it is like a reserve supply, ready for use when the body is low on free testosterone. However, scientists still don’t know how much bioavailable testosterone goes on to be absorbed by cells in these conditions. In most cases, bioavailable and free testosterone run even. Exceptions to this are known to manifest due to certain medical conditions and medications. For example, corticosteroids and sex steroids may cause an increase or decrease in SHBG amounts. In such instances, medical professionals may have difficulty properly diagnosing abnormalities. For this reason, it is critical that men disclose to their doctors all the medications they are taking as a part of their consultation. There are also other conditions that may cause diagnostic problems. These include:
1. Genetically caused SHBG-binding abnormalities
2. Liver disease
3. Severe systemic illness
Increasing Free Testosterone Levels There are two ways to improve free testosterone levels. In general, anything that increases total testosterone levels (such as forms of exercise or supplementation) will also elevate free testosterone. The other method involves reducing SHBG bound testosterone.
While the aging process naturally increases SHBG bondage, other factors can accelerate the process. Levels of certain hormones such as insulin, growth hormone, estrogen, and thyroid hormones are known to affect SHBG bonding. Vitamins and herbs, including vitamin D and boron are thought to lower SHBG.