Trust ProSource to fill all your supplement needs! Orders placed before 3pm EST ship same day. Want to speak to a customer representative? Our phones are open M-F 9-5. Click here for more information.


Free Vs Bound T

Free Vs Bound T

Buy AndroTest on Sale
Buy AndroTest on Sale

for a chance to win
this product!
It seems like everybody is talking about testosterone these days. What constitutes "normal" or "low testosterone levels?" What benefits can people who have chosen to support their testosterone production expect to see? Which technology of testosterone increase offers the greatest benefit in terms of dependability and sustainability?

At the same time, many people are unclear about the specifics of testosterone production and the role it plays in many aspects of male health and fitness. There are, for instance, three different markers of testosterone increase: free, bound, and total. How are each defined, and which is most crucial to increased vitality and virility? Let's take a look at the basics of testosterone, and then spotlight one particular mechanism of testosterone support that is generating a lot of excitement in scientific circles these days.

What Is Testosterone?
Testosterone is an androgenic anabolic steroid hormone that is derived from cholesterol and secreted by the testes and adrenal cortex (in small amounts) in males. Testosterone production is stimulated by luteinizing hormone (LH) released from the anterior pituitary, in a negative feed back loop. Thus (under normal healthy conditions), as testosterone levels decline, LH increases to stimulate increased testosterone production.

What Is The Difference Between
Free, Bound, and Total Testosterone?

When having your blood testosterone levels tested, you will likely receive two values on your chart: total testosterone and free testosterone. Your total testosterone measures all (i.e., free and bound) testosterone in the blood, so this number tends to be orders of magnitude higher than free testosterone numbers. This is because most of the circulating testosterone is bound to sex hormone-binding globulin (SHBG), with a smaller fraction bound to albumin, and the smallest proportion of testosterone being completely free.

Notably, the largest fraction of blood testosterone, SHBG bound testosterone is considered non-bioavailable since it cannot interact with testosterone receptors in the body.  Free testosterone and albumin bound testosterone are the most bioavailable fractions of testosterone in the blood, with albumin-bound testosterone being slightly less bioactive. However, since albumin binds testosterone weakly, it becomes free testosterone in the capillaries (the site of molecular exchange in all of our organs and muscles).

A normal healthy young man produces about 7 mg per day, of which less than 5% is derived from adrenal secretions. Testosterone in the blood is largely bound to plasma proteins with only a small fraction being free-testosterone.  Testosterone levels peak between 25 and 30 years of age and decrease by 1-2% per year thereafter. In healthy aging, the amount of testosterone produced gradually decreases to about 50%; however many environmental factors can prematurely lower the amount of free-testosterone (even in young men). A few common testosterone-lowering factors include work stress, alcohol consumption, and poor sleep and dietary habits.

Depending on which study you reference or the test used, normal total testosterone levels in men tend to range between 270-1100 ng/dl, while normal free testosterone levels can make up as little as fractions of a percent of total testosterone. The only way to really know if your levels are normal is to visit your physician for a physical examination, blood test, and report. However, common symptoms of low testosterone are low libido and erectile dysfunction, declining energy levels, depression, and, in extreme cases, hot flashes. If you are experiencing any or all of these symptoms, then see your physician for blood work.

Why Do You Want to
Maximize Testosterone Bioavailability?

For adult males, adequate blood testosterone concentration is integral in the production and maturation of sperm, maintaining the male reproductive system and libido. It also develops and maintains male secondary sex characteristics like body composition, hair pattern, aggression, deepening of voice, and bone mass.

In terms of muscle growth, testosterone stimulates protein synthesis, thus it is a major player in muscular development. Over the past several years, research suggests that testosterone levels in North American men are declining, a result of inactivity, increased body fat, and high levels of work stress. Although you may be in good shape, you are not immune from one or more environmental factors that lower bioavailable free-testosterone. In fit individuals, dieting, intense training, and age (if you are over 30) significantly impacts free-testosterone levels. Because of its profound effects on strength, protein synthesis, recovery, appetite stimulation, energy, and aggression, the need for testosterone optimization in weight-trained athletes cannot be overstated.

How Can I Naturally
Augment Bioavailable Testosterone?

First, you must eat, train, and sleep smart! An article from a research group in Auckland New Zealand has shown that load volume is the most important factor stimulating free testosterone increase. In the study the authors concluded that completing 10 reps at 75% 1RM, and 2 minutes rest between sets resulted in the most volume over the course of a complete workout and the greatest testosterone release. So what was taught in the 60's is still correct: OVERLOAD for growth!

Rest is also REALLY important. Overtraining results in a disturbance in the anabolic-catabolic balance. In such cases cortisol levels (among other things) increase and testosterone levels decrease, which severely hinders your muscle building goals. As always, you should make an effort to create a well-designed, periodized training program that includes adequate rest and above all listen to your body to avoid overtraining.

Buy AndroTest on Sale
Buy AndroTest on Sale

for a chance to win
this product!
What About Testosterone Boosters?
Today's most potent natural testosterone boosting compounds are botanical extracts called steroidal saponins and glycopeptides. To bodybuilders, the most important saponin is protodioscin, which (when administered in high concentration) promotes the greatest anabolic effects.  

Unfortunately, not all protodioscin-rich botanical extracts are created equal. A relatively recent publication has clearly illustrated that the concentration of protodioscin in herbal extracts is greatly influenced by the geographical origin, quality, and standardization procedures of raw materials.

Of all the protodioscin-based T-boosters available, the one that stands out in terms of research and potency is AndroTest by ProSource. ProSource's R&D team is comprised of PhD level scientists, who use the most stringent state-of-the-art laboratory procedures and certified Good Manufacturing Practices (GMPs), operating at a level that would rival big pharma companies.

The best products start with superior raw materials sourcing. In AndroTest's case, that means utilizing the highest-potency source of protodioscin, derived exclusively from a rare plant native to southern Bulgaria, and subjecting it to an advanced multiple extraction method. In contrast to conventional alcohol extraction methods, multi-phase extraction reduces the involvement of solvents and high heat, which yields significantly higher purity, reduces residual solvents in the final product, and reduces thermal damage to active compounds. With such stringent levels of quality control AndroTest is the only full spectrum protodioscin-rich botanical super compound standardized (and guaranteed) to contain a minimum of 80% total steroidal saponins, 60% total furostanol saponins, with 40% protodioscin and 28% steroidal glycopeptides, a level of potency that is not offered by any competitor.

How Does AndroTest Work?
Last year's case studies for AndroTest were so compelling that they've already served as the impetus for new investigations aimed at elucidating the mechanism(s) behind AndroTest's testosterone boosting potential. A leading theory postulates that since AndroTest has been shown to significantly boost total and free testosterone, then its key active ingredient may act on multiple levels. Firstly, it may boost LH to signal the testes to produce and secrete more testosterone, thus increasing total testosterone. At the same time, this powerful protodioscin-rich super compound may decrease SHBG levels in the blood, consequently decreasing SHBG-bound testosterone. This would increase bioavailable free testosterone levels. This is a crucial distinction, because free testosterone is the driving factor behind all the benefits associated with high T levels, while SHBG-bound testosterone literally functions as reserved (and thus temporarily inert) testosterone.

While many of us are looking forward to the findings of future clinical inquiries, right now there can be little doubt that AndroTest is causing a sensation among men seeking to regain their edge through enhanced T levels. Real, sustainable support of the hormone most essential to male performance, physique, and overall vitality is now a reality for men who want to look, feel, and be their best. The science of natural test-boosting supplementation has arrived and it bears the AndroTest name.

Other Articles You May Be Interested In

Use as directed and with a sensible nutrition and exercise program. Read all product labels and warnings before use. A 4 week study of healthy males showed a 59.75% average increase in free testosterone compared to baseline, and 59.88% average increase in total testosterone, compared to baseline. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.