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.


Test Prep

Exploring Alternative Technologies
Of Natural Testosterone Support

The importance of testosterone in a strength training program cannot be emphasized enough.  All the way from gains in lean muscle mass to reductions in body fat to enhanced strength, testosterone plays an essential role in facilitating training adaptations for athletes. There are several ways to support testosterone levels through nutrition, sleep and certain principles of training, but what happens when these things aren’t enough? Outside of injection of testosterone directly into the muscle (a uniquely poor choice for a variety of physical and legal reasons) boosting testosterone levels may be difficult. Fortunately, a number of supplemental technologies offer the option of supporting testosterone levels naturally, while others address the utilization of testosterone within the body.  

L-Carnitine: Versatile Super
Nutrient for Bodybuilders

L-carnitine, often regarded as a fat-loss supplement, is an example of a dietary ingredient that’s thought to have an impact on testosterone. L-carnitine is a naturally occurring compound within the human body with a similar chemical structure to that of amino acids and B vitamins.  L-carnitine is most commonly found in animal and dairy products, and is thought to play a role in the production of testosterone through both central and peripheral production pathways.

In addition, it also appears to influence how testosterone is utilized within the body, specifically during the time period following a bout of resistance exercise.  Researchers have found that following several weeks of L-carntine supplementation, individuals experienced an increase in androgen receptor content which essentially determines how much bioavailable testosterone can be utilized at any given time (1). This allows one to better capitalize on increased testosterone levels following a training session as an increase in the number of receptor sites will aid in the uptake of testosterone.

Researchers studying supplementation of L-carnitine have also documented increases in luteinizing hormone which plays a crucial role in the stimulation of testosterone production within males. Other studies have shown L-carnitine supplementation to promote an anabolic environment by reducing the catabolic response to training.  Specifically, researchers found a 40% reduction in exercise-induced muscle damage following a bout of resistance training (2). The researchers concluded that because carnitine appears to enhance blood flow to the muscles during exercise that it may ultimately help to reduce oxidative stress in addition to enhancing hormone (testosterone) availability.

As was mentioned previously, L-carnitine is typically regarded as a fat-loss aid, as it can help support the utilization of fat as a fuel source due to its ability to transport fatty acids into certain organelles within muscle cells that can be used for fuel production. So, as an added bonus, not only can L-carnitine help support healthy hormonal function, in may also help shed some unwanted body fat. When supplementing with L-carnitine, it appears as though taking it with carbohydrates may be advantageous. Enhanced uptake of L-carnitine into the muscle, meanwhile,  may help improve insulin sensitivity.

L-Carnitine as Part of a Multi-Vector
Approach to Supporting Testosterone

L-carnitine supplementation is best indicated in the form of L-carnitine-L-tartrate, as that is the naturally occurring form and one that is bioavailable within the human body. A typical recommended dosage is approximately two grams, which is precisely the amount in BioQuest’s superior AndroCept technology. AndroCept not only contains a scientifically formulated L-carnitine-L-tartrate blend, but also combines it with Vitamin D and zinc as well, two other testosterone-supporting ingredients.

Vitamin D, a vitamin that acts more like a hormone than a vitamin, has also been shown to positively influence testosterone levels. Vitamin D appears to help with improving testicular health and hormone production, which is why it’s thought that Vitamin D can help to support testosterone levels.  Researchers have found that long-term Vitamin D supplementation can help support testosterone levels in men (3). It is possible to get Vitamin D from sunlight exposure; however the majority of the population in the U.S. is actually Vitamin D deficient, especially those people living in northern states during the winter months, and therefore supplementation is often necessary. AndroCept's sophisticated matrix of test-support vectors makes it a highly worthwhile addition to your supplement regimen.

ZMA: Another Weapon In Your
Testosterone-Support Arsenal

Another common supplement geared towards testosterone optimization is Zinc-Magnesium-Aspartate (also typically combined with Vitamin B6) which seems to be an anabolic trifecta of ingredients designed to enhance your anabolic potential. Zinc is a mineral that is involved in several chemical reactions within the body. Specifically, zinc appears to influence the maintenance of cells and various tissues throughout the body that help promote protein synthesis and support immune function.

ZMA supplementation may be particularly important for active individuals as these minerals are often under-consumed and can be lost through sweat. People may need to supplement with ZMA if they are not getting enough through their daily diet, as it can have an impact on training adaptations. In one study, researchers found that ZMA supplementation increased testosterone and strength levels in football players during their off-season training program (4). There is also evidence to suggest that zinc can act as an antioxidant, which in conjunction with L-carnitine may further help to reduce muscle damage during intense training. ProSource ZMA is an advanced ZMA product, 100% sourced with industry-leading SNAC Systems ZMA, with just the right ratio of zinc, magnesium and aspartate. For maximal uptake, take ZMA in between meals and make sure to avoid calcium supplements or foods high in calcium as it can interfere with ZMA absorption.

AndroTest: Unrivaled T-Boosting Effectiveness

Although this article is intended to spotlight alternative means of testosterone support, no discussion of supplemental methods for naturally supporting testosterone production would be complete without mentioning the primary and most important agent of testosterone support in the industry today, ProSource’s AndroTest. Since the day it first appeared, AndroTest has established itself as the gold standard for natural testosterone support, both in regard to ingredient quality and processing/refinement. AndroTest’s key ingredient, a full-spectrum protodioscin-rich botanical super-compound, is synthesized via a painstaking refinement method that can include up to 20 separate extractions. The result is the first natural T-booster ever standardized for a minimum of 40% bioactive protodioscin levels. No other manufacturer has ever approached this level of sophistication and diligence in its manufacturing protocols, and none (to our knowledge) intends to start any time soon.

How potent is AndroTest? Well, in a randomized, placebo-controlled, double blind clinical study, AndroTest produced statistically significant increases in total testosterone levels, averaging 59.88% over baseline, with some subjects showing total increases as high as 275% over baseline. Major increases in free testosterone were documented as well, averaging 59.75% over baseline, with some subjects reaching up to 218% over baseline. AndroTest has really taken testosterone-boosting supplements to the next level with its advanced, scientifically supported clinical formula and the high amounts of testosterone boosting natural ingredients. By all means, explore the many complementary benefits of L-carnitine-L-tartrate and ZMA, but also recognize that if you’re serious about supporting your T-levels in the normal, healthy range, AndroTest is an essential supplement for you.

For a more thorough discussion of AndroTest, featuring some of the supplement industry's leading experts, check out Supplement Picks of the Experts: Testosterone Support.


So if you’re looking for ways to boost your testosterone levels to maximize strength and muscle gains, try adding AndroCept or ZMA to your stack regimen. And if you really want to set yourself up for maximal testosterone levels, try adding AndroTest, a premier testosterone booster in the supplement market, into the mix.  These supplements can help smash through any training plateaus especially during periods of high volume training.

Read more about BioQuest AndroCept.

Read more about ProSource ZMA.

Read more about ProSource AndroTest.


1.     Kraemer WJ, Spiering BA, Volek JS, Ratamess NA, Sharman MJ, Rubin MR, French DN, Silvestre R, Hatfield DL, Van Heest JL, Vingren JL, Judelson DA, Deschenes MR, Maresh CM. Androgenic responses to resistance exercise: effects of feeding and L-carnitine. Med Sci Sports Exerc. 2006 Jul;38(7):1288-96.

2.     Kraemer, W. J., Volek, J. S., French, D. N., Rubin, M. R., SHARMAN, M. J., Gomez, A. L., ... & Hakkinen, K. (2003). The effects of L-carnitine L-tartrate supplementation on hormonal responses to resistance exercise and recovery.The Journal of Strength & Conditioning Research, 17(3), 455-462.

3. Pilz, S., Frisch, S., Koertke, H., Kuhn, J., Dreier, J., Obermayer-Pietsch, B., ... & Zittermann, A. (2011). Effect of vitamin D supplementation on testosterone levels in men. Hormone and Metabolic Research, 43(3), 223.

4. Brillia, LR., Conte, V. Effects of a novel zinc-magnesium formulation on hormones and strength. J Exerc Physiol Online. 200; 3: 26-36.

5. Kilic M et al. The effect of exhaustion exercise on thyroid hormones and testosterone levels of elite athletes receiving oral zinc. Neuro Endocrinol Lett. 2006 Apr 25;27(1-2):247-252.

6.  Lukaski HC. Magnesium, zinc, and chromium nutriture and physical activity. Am J Clin Nutr. 2000 Aug;72(2 Suppl):585S-93S.

Use as directed. Read all product label instructions and warnings thoroughly 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.