Overview and History of Testosterone Suspension
Testosterone Suspension is an injectable preparation of pure, un-modified and un-esterified Testosterone, almost always suspended in a water base within microcrystals (hence the name Testosterone Suspension). Within the bodybuilding and athletic world, Testosterone Suspension is regarded as the most potent and strongest form of injectable Testosterone available, and it is known for producing some of the most rapid mass, strength, and physique changes out of all injectable preparations of Testosterone. This is for several reasons. The first reason is because this is the purest form of Testosterone, unmodified and unesterified, meaning it is instantly active the minute it is injected into the body. Also, because there is no added ester bonded to the Testosterone molecule, there is more total Testosterone per mg of Testosterone Suspension, making it a far more potent product. Because ester weights must be factored into the total weight of the substance, esterified formats of Testosterone (or any hormone) such as Testosterone Propionate, Testosterone Enanthate, and Testosterone Cypionate do not all yield 100mg of Testosterone in 100mg of Testosterone Enanthate, for example. Once the body cleaves off the ester that is bound to the molecule, the weight of the ester is removed, and so for example, in 100mg of Testosterone Enanthate, there is in reality approximately 70mg of Testosterone. 100mg of Testosterone Suspension, however, yields exactly 100mg of Testosterone. Because esterified variants of Testosterone have longer half-lives and require their esters to be removed (before releasing pure Testosterone), optimal peak blood plasma levels are achieved often in weeks of use. This is not the case with Testosterone Suspension, where optimal peak blood plasma levels are achieved in a matter of hours instead.
For example, it takes approximately 4 or 5 weeks (some users even report as late as 6 weeks) of use of the longer Testosterone esters, such as Testosterone Enanthate and Cypionate, before mass and strength gains are experienced. With Testosterone Suspension, gains are normally experienced within the first week of use, and by 4 weeks into a Testosterone Suspension cycle, the bulk of the gains will usually have been achieved (meanwhile by this same time period, the longer acting formats of Testosterone will only just have begun taking effect).
Testosterone Suspension is perhaps the oldest anabolic steroid preparation, first isolated and synthesized in the early 1930s by German scientists. It is the very first preparation of Testosterone to ever be created for use, and pre-dates the slower acting esterified variants of Testosterone by a matter of several years. Testosterone Propionate was developed towards the mid-1930s, and Testosterone Enanthate was available in the 1950s, but Testosterone Suspension still remained popular during this period of time even though it was widely regarded as a much more crude form of Testosterone that was inconvenient and uncomfortable to inject due to the painful injections, and the very short half-life that necessitated very frequent injections. By comparison, Testosterone Propionate required injections every other day to every four days, and Testosterone Enanthate required injections to be administered once or twice per week. Testosterone Suspension requires at least daily injections, if not multiple times per day. Testosterone Suspension is the longest lasting Testosterone product on the prescription market, both in the USA and abroad and can be found under many American trade and brand names, such as Sterotate by Ulmer, Andronaq by Central, Aquasuspension Testosterone by Pitman-Moore, Injectable Aqueous Testosterone by Arlongton-Funk, Virosterone by Endo, and Testosterone Aqueous by National Drug Company. Testosterone Suspension is perhaps so widely available and manufactured in such numerous quantities and brands that there are countless amounts of brand names as well as generics.
Clinical and medical application of Testosterone Susp was, of course, identical to that of all other Testosterone products. This included treatment of the following conditions: treatment for low libido (lack of sex drive), male impotence, hypogonadism and andropause (insufficient Testosterone production in males), the treatment of delayed-onset puberty in adolescent males, and even in females for the treatment of breast cancer as well as a few other conditions. Towards the late 1980s and 1990, the FDA, as it had done with all other anabolic steroids, amended the list of approved treatments by shortening it. Testosterone Suspension was then determined as a drug to focus almost exclusively on the treatment of hypogonadism and andropause, but is still today also reserved as a last resort therapy for the treatment of female breast cancer (though this is very rare considering the high incidence of virilization that Testosterone causes in females).
Testosterone Suspension was in fact utilized quite extensively up until 1998 on the American prescription market. In 1998, Testosterone Suspension was primarily manufactured by Steris Laboratories in the United States, making it one of the last companies to manufacture the drug for medical use. Because of a small issue in regards to the dispensing of Schedule III drugs at the time, the FDA was forced to cause Steris to suspend production of all Schedule III drugs (including Testosterone Suspension) due to discrepancies in their inventory reports. It was not until several years down the line that Steris had the opportunity to pick up the manufacture of Testosterone Suspension once again, but they decided against it. Because of this, pharmaceutical grade Testosterone Susp is today available on the US prescription market only via private compounding pharmacies, making the drug a special-order item that can be difficult to acquire. It is also still widely available as a veterinary medicine.
Because of the wide variation and selection of Testosterone Suspension throughout the world, the doses and concentrations it is available in varies greatly, with some products containing 100mg/ml or 50mg/ml (very common). Testosterone Suspension can be found contained in either 1ml ampoules or 10ml multidose vials.
Chemical Characteristics of Testosterone Suspension
Testosterone Suspension is an injectable Testosterone product that contains free, pure, unmodified Testosterone in microcrystalline format that is suspended in a water base. Because there is no ester bond on the Testosterone molecule in this case, its half-life is greatly reduced compared to other injectable formats of Testosterone, making its half-life a matter of 2 – 4 hours (with some studies stating as high as 24 – 39 hours). Once again, as stated earlier, it is important to understand that because Testosterone Suspension does not contain an carboxylic acid esterified to it, an individual using it is receiving far more Testosterone per mg of injection than with any other form of Testosterone. 100mg of Testosterone Suspension yields 100mg of Testosterone. By comparison, 100mg of Testosterone Enanthate yields only 70mg of Testosterone (after the Enanthate ester has been removed by enzymes in the body, leaving free Testosterone).
Properties of Testosterone Suspension
Testosterone has always been known to promote large amounts of nitrogen retention in muscle tissue, with studies indicating significant increases in fat-free mass and muscle size as a result. Testosterone is also well-known for its ability to significantly increase levels of IGF-1 (Insulin-like Growth Factor 1) in muscle tissue, which further contributes to significant increases in muscle size and strength. A study on Testosterone’s action within muscle tissue indicated that this primarily occurs through its ability to activate satellite cells in muscle tissue, which is very important in the role of repairing damaged muscle fibers. That same study also indicated that Testosterone exhibits the ability to inhibit adipogenesis (the storage of fat) as well as the ability to increase the size of motor neurons. Testosterone has been found to achieve its muscle growth and strength-promoting effects primarily through the interaction with the androgen receptor located in muscle cells as one of its primary mechanisms. Androgens such as Testosterone also increase red blood cell count via a stimulation of the increase of Erythropoietin in the kidneys, resulting in better oxygen transport throughout the body, thus increasing the endurance capabilities of the athlete.
Testosterone in general is regarded as one of the best mass-adding and bulking agents. Those who wish to bulk up will experience more rapid results with the use of Testosterone Suspension than with any other form of Testosterone. It has also been found that there is a relationship between the dose used and the amount of muscle growth whereby the higher the dose, the greater the growth experienced. Testosterone is what would be considered as the original anabolic steroid, manufactured naturally and endogenously within all humans and in most animal species. Testosterone Suspension can be utilized for any particular goal, as Testosterone is the most versatile anabolic steroid.
Chemical Name: 4-androsten-3-one-17beta-ol, 17beta-hydroxy-androst-4-en-3-one
Molecular Weight: 288.42 g/mol
Original Manufacturer: N/A
Half Life: 2 – 4 hours (some reports as long as 39 hours)
Detection Time: 1 – 3 days
Anabolic Rating: 100 Androgenic Rating: 100
Testosterone Suspension References:
 J Vet Pharmacol Ther. 2011 Mar 2. doi: 10.1111/j.1365-2885.2011.01277.x
 Testosterone replacement increases fat-free mass and muscle size in hypogonadal men. Bhasin S, Storer TW, Berman N, Yarasheski KE, Clevenger B, Phillips J, Lee WP, Bunnell TJ, Casaburi R. J Clin Endocrinol Metab. 1997 Feb;82(2):407-13.
 Testosterone administration to older men improves muscle function: molecular and physiological mechanisms. Ferrando AA, Sheffield-Moore M, Yeckel CW, Gilkison C, Jiang J, Achacosa A, Lieberman SA, Tipton K, Wolfe RR, Urban RJ. Am J Physiol Endocrinol Metab. 2002 Mar;282(3):E601-7.
 Testosterone action on skeletal muscle. Herbst KL, Bhasin S. Curr Opin Clin Nutr Metab Care. 2004 May;7(3):271-7.
 Targeting steroid hormone receptor pathways in the treatment of hormone dependent cancers. Ko YJ, Balk SP. Curr Pharm Biotechnol. 2004 Oct;5(5):459-70.
 Effect of androgen on erythropoietin in patients with hypogonadism. Cui YG, Tong JS, Pan QQ, Di FS, Jia Y, Feng T, Liu Y, Wang XH, Zhang GY. Zhonghua Nan Ke Xue. 2003;9(4):248-51.
 Testosterone dose-dependently increases maximal voluntary strength and leg power, but does not affect fatigability or specific tension. Storer TW, Magliano L, Woodhouse L, Lee ML, Dzekov C, Dzekov J, Casaburi R, Bhasin S. J Clin Endocrinol Metab. 2003 Apr;88(4):1478-85.