Free Testosterone (Bioavailable Testosterone): Why is it Critical in Treating Low T

Back in the old days, there was this “thing’ called recess where kids in elementary school got to go outside and play several times a day. Granted, this session of physical activity might still be hanging on by a string in some schools, but on the average, it has slowly disappeared in conjunction with the rise of childhood obesity.

What does this have to do with free testosterone? Well, it’s just a comparison. If you had the luxury of having recess when you were young, you would bolt out the door and go get your play on and you were free to do what you want. You were no longer bound to rule or a desk in a classroom.

Well, free testosterone is much the same. Here is a little more in-depth explanation that will set the record straight for you. And, just FOR the record, testosterone is perhaps THE most important hormone in the male body. But you probably knew that already. And to you ladies out there, it’s still important. Just not to as high a degree as males.

What is Free Testosterone?

The pituitary gland is about as big as a pea and it sits right smack dab in the center of your forehead. Aside from its job in making you grow taller, it also carries one more very important task on its shoulders. It kickstarts the testosterone production process into motion.

To be more specific, it works a little something like this. Your body actually goes through a series of stimulation processes. First, your hypothalamus stimulates your pituitary gland to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

Then these hormones stimulate your testes to produce testosterone, which then gets secreted into your system. All of this magic happens when your t-levels dip and your body asks for more.

Now, some of this testosterone is bound to other chemicals in the body, which makes it unusable. These would be albumin and sex-hormone binding globulin, or SHBG for short. The testosterone that is not attached is free testosterone.

Think back to the example of the kids at recess. At one point they were held at bay, learning their ABCs and the next they were free to move. Testosterone works in a similar way.

Understanding Bioavailable Testosterone vs. Bound Testosterone

To get a little more technical, testosterone is either bioavailable or bound. Obviously, if something is bound, it is tied up and unable to do anything. It’s just like being bound and gagged in real life. You surely aren’t going anywhere.

Then you have bioavailable. The root word “available” should pretty much spell it out. Bioavailable testosterone is free for you to use for all the stuff it is needed for in the body. And it is THIS form of testosterone that you want to have a high level of. Or at least, normal levels of.

What Does Free Testosterone Do?

As briefly mentioned above, free testosterone is often referred to as the master hormone in the body, especially for men. It is the sayer and doer of basically every function and characteristic that makes a man a man.

For women, it is only produced in small amounts in the ovaries. But, that doesn’t mean it is unimportant. It still helps to balance out all the female systems, and if it was too low, you would definitely notice.

Here are some of the main functions of free testosterone:


Right at the top of the list, and for good reason, you have energy. When t-levels are high, so is your ability to move with a spring in your step and also think equally as quick. And sort of along the same lines of energy, you are able to sleep well.

If your t-levels are low, you sometimes have a hard time falling asleep and staying asleep. This has an obvious negative impact on energy levels.


Testosterone is also known as a primary sex hormone. In men, it means everything to a sex life and it only does to a lesser degree with women.

That being said, testosterone helps with sex drive, erectile function and all-around sexual desire.


The brain feels the effects of testosterone just as much as the rest of the body. When t-levels are firing on all cylinders, you are in a better mood, you can think clearly and your memory is on point.

This sort of goes hand-in-hand with sexual function. If you are in a bad mood, stressed or depressed, you likely won’t want to have sex.


Perhaps the most common association with testosterone is its affect on muscle. At least, if you were to talk to any bodybuilder or hardcore gym goer, they would tell you of its importance.

In this case, it is a precursor to building muscle, maintaining muscle and having the drive to push heavy weights.

How to Determine Your Free Testosterone Levels

If you suspect that your levels of testosterone are low, it is a good idea to find out for sure. Just speculating and doing something about it that might cause further risk to your health is never the best approach.

You are better served going a direction that involves a specialist that you know and trust. Any primary care physician would be able to do this for you.

Free Testosterone Test

The actual test that can determine your levels is a blood test, and you have a couple different routes to take as far as getting this done is concerned. Both of which are relatively easy.

First of all, you can schedule an appointment with your doctor and visit the office. Generally, he will give you a quick exam and ask you a few questions and then you will get a blood draw from his PA or a nurse.

This procedure is fast and easy. Just be aware that you are getting a needle in your arm for the blood draw. If you are squeamish at the sight of blood, you might want to turn your head to the side. If it’s any bonus, the test is relatively painless. It feels about like a bee sting.

The other option is you can have a phlebotomist sent to your house to do the draw. You can expect the exact same process, except you don’t even have to leave the comfort of your home.

Normal Levels of Free Testosterone

There is quite a variance in free testosterone range pertaining to age. It is most high when you are young and is the main reason for body hair growth, a deeper voice and sexual characteristics appearing.

That being said, it reaches a peak at about 30 years old and slowly declines about 1% every year thereafter as a rule of thumb. But in the meantime, it is good to have an idea of what the ranges are, so you can determine if you are justified in seeking treatment for low levels.

Since you are most likely over the age of 19, which is considered an adult, the range is 270 to 1,070 ng/dL. Having said that, you can see that this is a pretty wide range.

The problem sets in when your levels might be on the higher end, yet you still don’t feel yourself. That indicates that there might be a different underlying problem going on and you should definitely talk this over with your doctor.

Is there a Free Testosterone Calculator?

When you get your lab results back, you will see a number of indicators on it. Do you remember albumin and SHBG from a while back? They will appear on your test results. They are the chemicals that testosterone are often attached to, making it unusable.

Well, you can find a calculator online that allows you to punch in your albumin, SHGB and total testosterone based off your test. Then it will give you the percentage of free testosterone you actually have. And this ranges between 1.5 and 2.5% of your total number. If you are closer to 2.5%, then you’re where you want to be.

How to Increase Your Free Testosterone Range

If you have been diagnosed with low T, don’t be too alarmed just yet. You can definitely seek out hormone replacement therapy in an attempt to get back in balance. But, that can cause some complications and possibly come with side effects.

In this case, there are some natural ways that you can get your body back into the production mode. One of which is testosterone boosters.

Do Testosterone Boosters Work?

First of all, a testosterone booster is a supplement that contains a number of vitamins, minerals, plant extracts or herbs that is designed to boost your t-levels. Some of these include magnesium, zinc, D-aspartic acid stinging nettle, tribulus terrestris and panax ginseng.

Companies of all shapes and sizes produce an array of products with some or all of these ingredients and claim that they will get you back into balance. On paper, it sounds like a great idea. The only problem is, the results are variable at best.

There are a lot of factors that depict whether a t-booster will work or not. First and foremost, everyone reacts differently to different things. So if subject A gets great results, it doesn’t mean subjects B, C and D will. Just like no two people are completely alike, no two people will have the same benefits.

Plus, you have to look at the rest of the stuff the people do who are taking these. If someone eats clean, gets to bed early every night and is physically active, they are in better position to get good results from a booster.

But, often times, men who live unhealthy lives, continue to do so when taking a booster and they think miracles will happen. Unfortunately, that’s just not how the body works. When you go the natural route, it has to be a wholistic, all or nothing approach.

That being said, unless you are specifically allergic to an ingredient in a testosterone booster, it won’t harm you to try it out. Just use it as directed and stop the second you feel any side effects or that it’s not working. There’s no sense wasting money on something that’s not going to help you.

Lifestyle Changes to Boost Free Testosterone

Here is where you really want to pay close attention. You may not have been aware of this, but there are a handful of things you can start doing right now to help increase your t-levels. And if you already know that your levels are high, you should still do these things to ensure that they stay that way.

First of all, you can do amazing things by making changes to your diet. Cruciferous vegetables, for example contain powerful substances called indoles. When you take these into your body, they suppress estradiol levels. If you focus on the root word, “estrogen,” you’d know that this is the main female hormone.

Estrogen and testosterone can’t both be high at the same time. So if you eat cruciferous vegetables regularly, like broccoli, cauliflower, brussels sprouts, kale, cabbage and chard, you can lower your estrogen and raise your testosterone.

It’s also a smart idea to avoid foods and beverages that can lower testosterone like soy products, flax seeds, excessive amounts of alcohol and processed meats that are high in hormones, antibiotics and sulfites.

Lastly, here are a few other tips to get your testosterone headed in the right direction.

  • Lose stomach fat
  • Get adequate sleep
  • Get at least 30 minutes of sun exposure a day.

Workouts that Maximize Free Testosterone Levels

One last way to naturally boost testosterone hinges around your workouts. There is a right and wrong way to lift weights. And, there is a right and wrong way to use exercise to your advantage when it comes to testosterone boosting. Here is the right way.

To put it simply, you want to train at a high intensity. This means, lift heavy weights, do compound exercises that recruit more than one muscle group and also take shorter rest breaks.

Doing all of this causes an anabolic response in your system, which will pump out more testosterone.

You can also add sprint training to the mix to round things off. Not only will this help boost testosterone, but it will also melt away layers of fat quickly that could be hindering your levels.

And one last trick of the trade. Work out in a fasted state. Ideally it is at least 10 hours, but you will likely get a higher output in the 16-plus range. When you work out fasted, your body gets confused because it thinks a disaster is about to happen and it wants to hold onto stored muscle for strength.

Since there is no food in your gut, it decides to release more growth hormone and testosterone. Use this little trick to your advantage.

Follow the Sunlight

You now have a very solid background on free testosterone. If you think your levels are low, you now know how to get them checked and what they should look like. If you are looking to keep them high, then you also know how to do that.

In all cases, the easiest way to give them a boost is to simply follow the sunlight. Get outside and get as much of your flesh exposed to the sun as possible. And the reason why is because the sun causes your body to release a high amount of vitamin D, which is a precursor to testosterone release.

When it’s all said and done, just know that there are ways to boost your t-levels through natural means. Use them to the best of your ability.