Testosterone suspension is an injectable preparation containing testosterone (no ester), usually in a water base. Among bodybuilders, “suspension” is known to be an extremely potent mass agent. It is often said to be the most powerful injectable steroid available, producing very rapid gains in muscle mass and strength. This is largely due to the very fast action of the drug. When using a slow-acting oil-based steroid like Sustanon® 250, it can take weeks before a peak testosterone level is reached. With suspension, it is just a matter of hours. This will usually result in the athlete starting to notice size and strength gains by the end of the first week. By the time the athlete is 30 days into a cycle of suspension, the length it will usually take for Sustanon® 250 to really begin working consistently, the mass gains are already (generally) very extreme.
Testosterone suspension contains (free) testosterone in a water-based suspension, although oils are sometime also used as carriers. Without esterification, testosterone has a short half-life in the body. Testosterone suspension may require a minimum of 2-3 injections per week to maintain consistent hormone elevations. When calculating dose, especially when moving from one testosterone preparation to another, it is also important to remember that testosterone suspension contains more active testosterone per milligram than its esterified derivatives. For example, when the weight of the ester is taken into account, 100 mg of testosterone enanthate actually only provides 72 mg of raw testosterone.
Testosterone suspension contains undissolved testosterone particles, which form a short-acting repository in the muscle following injection. Depending on the size of the particles and other agents present, injections of testosterone suspension may result in local irritation, pain, and redness. Veterinary testosterone suspensions may use large particles that require a needle as large as 21 gauge for injection, for example, and can be very uncomfortable to use. Modern testosterone suspension preparations made for human use often contain microcrystalline steroid particles. These crystals are highly refined, and are too small to see with the naked eye. This design provides significantly more patient comfort than less refined products, and is generally well tolerated.
To treat androgen insufficiency, the prescribing guidelines for testosterone suspension recommend a dose of 25-50 mg, which is given 2-3 times per week. When used for muscle-building purposes, testosterone suspension is often administered at a dose of 100-200 mg per injection, which is given every 2nd or 3rd day. Athletes looking to achieve an extremely rapid bulk gain will inject as much as 100 mg daily. In most cases this higher dose can be amazing, the user seeming to just inflate with bloated muscle mass in a very short period of time. Back when they were being manufactured, the U.S. 30 mL vials (100 mg/mL) were always the most sought after for this procedure, as each would run the cycle for about a month. Although this drug does require a frequent injection schedule, a well-refined suspension should pass through a needle as fine as 27 gauge (insulin). This allows the user more available injection sites, hitting the smaller muscle groups such as the deltoid, triceps, and calves.
Those looking for only a potent mass agent are often extremely happy with the results provided by testosterone suspension; this product certainly has a strong reputation for performing. But those athletes who want not just quantity but quality are likely to be disappointed, as the muscle mass gain is not going to be a hard, dense one. In fact, the user will often have to contend with excessive fat and water-weight gains when building their physique with this drug, and will often seek the benefit of cutting agents soon afterwards to clean up the look of muscularity. Alternately, one could make use of a smaller dosage of testosterone suspension, which would allow for less estrogen buildup. In such a scenario, one could stack it with any of a variety of other less or non-aromatizable steroids, depending on the desired goals.
Testosterone suspension is rarely used with women in clinical medicine. When applied, it is most often used as a secondary treatment for inoperable breast cancer. Doses given for this application may reach 100 mg three times per week, a level well into the threshold likely to cause strong virilizing side effects. Testosterone suspension is not recommended for women for physique- or performance-enhancing purposes due to its strong androgenic nature and tendency to produce virilizing side effects.
Testosterone is readily aromatized in the body to estradiol (estrogen). The aromatase (estrogen synthetase) enzyme is responsible for this metabolism of testosterone. Elevated estrogen levels can cause side effects such as increased water retention, body fat gain, and gynecomastia. Testosterone is considered a moderately estrogenic steroid. An anti-estrogen such as clomiphene citrate or tamoxifen citrate may be necessary to prevent estrogenic side effects. One may alternately use an aromatase inhibitor like Arimidex® (anastrozole), which more efficiently controls estrogen by preventing its synthesis. Aromatase inhibitors can be quite expensive in comparison to anti-estrogens, however, and may also have negative effects on blood lipids.
Estrogenic side effects will occur in a dose-dependant manner, with higher doses (above normal therapeutic levels) of testosterone more likely to require the concurrent use of an anti-estrogen or aromatase inhibitor. Since water retention and loss of muscle definition are common with higher doses of testosterone, this drug is usually considered a poor choice for dieting or cutting phases of training. Its moderate estrogenicity makes it more ideal for bulking phases, where the added water retention will support raw strength and muscle size, and help foster a stronger anabolic environment.
Testosterone is the primary male androgen, responsible for maintaining secondary male sexual characteristics. Elevated levels of testosterone are likely to produce androgenic side effects including oily skin, acne, and body/facial hair growth. Men with a genetic predisposition for hair loss (androgenetic alopecia) may notice accelerated male pattern balding. Those concerned about hair loss may find a more comfortable option in nandrolone decanoate, which is a comparably less androgenic steroid. Women are warned of the potential virilizing effects of anabolic/androgenic steroids, especially with a strong androgen such as testosterone. These may include deepening of the voice, menstrual irregularities, changes in skin texture, facial hair growth, and clitoral enlargement.
In androgen-responsive target tissues such as the skin, scalp, and prostate, the high relative androgenicity of testosterone is dependant on its reduction to dihydrotestosterone (DHT). The 5-alpha reductase enzyme is responsible for this metabolism of testosterone. The concurrent use of a 5-alpha reductase inhibitor such as finasteride or dutasteride will interfere with site-specific potentiation of testosterone action, lowering the tendency of testosterone drugs to produce androgenic side effects. It is important to remember that anabolic and androgenic effects are both mediated via the cytosolic androgen receptor. Complete separation of testosterone’s anabolic and androgenic properties is not possible, even with total 5-alpha reductase inhibition.
(Source: Anabolics - by Willaim Llewellyn.)