Sustaxyl 350 (testosterone blend) is an oil-based injectable testosterone blend that contains four different testosterone esters:Testosterone Decanoate 140mg/ml, Testosterone Phaenylpropionate 84mg/ml, Testosterone Propionate 42mg/ml, Testosterone Isocarpoate 84mg/ml. Sustaxyl 350 is designed to provide a fast yet extended release of testosterone, usually requiring injections once every 3 to 4 weeks in a clinical setting. This is an improvement from standard testosterones such as cypionate or enanthate, which provide a shorter duration of activity. As with all testosterone products, Sustaxyl 350 is a very strong anabolic drug with pronounced androgenic activity. It is most commonly used in bulking cycles, providing exceptional gains in strength and muscle mass.Sustaxyl 350 contains a mixture of four testosterone compounds, which where modified with the addition of carboxylic acid esters (propionic, propionic phenyl ester, isocaproic, and decanoic acids) at the 17-beta hydroxyl group. Esterified forms of testosterone are less polar than free testosterone, and are absorbed more slowly from the area of injection. Once in the bloodstream, the ester is removed to yield free (active) testosterone. Esterified forms of testosterone are designed to prolong the window of therapeutic effect following administration, allowing for a less frequent injection schedule compared to injections of free (unesterified) steroid. Sustanon 250 is designed to provide a rapid peak in testosterone levels (24-48 hours after injection), and maintain physiological concentrations for approximately 21 days.Each 250 mg ampule provides 176mg of testosterone.
Testosterone propionate is often regarded as a painful injection. This is due to the very short carbon chain of the propionic acid ester, which can be irritating to tissues at the site of injection. Many sensitive individuals choose to stay away from this steroid completely, their bodies reacting with a pronounced soreness and low-grade fever that may last for a few days after each injection.
To treat androgen insufficiency, the prescribing guidelines for Sustaxyl 350 call for a dosage of 350 mg every 3 weeks. Although active in the body for a longer time, Sustaxyl 350 is usually injected every 7 to 10 days for muscle-building purposes. This schedule will allow for the higher doses most commonly applied by athletes, and more stable elevations in hormone level. The usual dosage among male athletes is in the range of 250-750 mg per injection, taken in cycles 6 to 12 weeks in length. This level is sufficient for most users to notice exceptional gains in muscle size and strength. Sustaxyl 350 is usually incorporated into bulking phases of training, when added water retention will be of little consequence, the user more concerned with raw mass than definition. Some do incorporate this drug into cutting cycles as well, but typically in lower doses (125- 250 mg every 710 days) and/or when accompanied by an aromatase inhibitor to keep estrogen levels under control. Sustaxyl 350 is a very effective anabolic drug, and is often used alone with great benefit. Some, however, find a need to stack it with other anabolic/androgenic steroids for a stronger effect, in which case an additional 200-400 mg per week of boldenone undecylenate, methenolone enanthate, or nandrolone decanoate should provide substantial results with no significant hepatotoxicity. Testosterone is ultimately very versatile, and can be combined with many other anabolic/androgenic steroids to tailor the desired effect. Some bodybuilders have been known to use excessively high dosages of this drug (1,000 mg per week or more), although this practice is generally not advised. At dosages above 750 mg per week, water retention will likely account for more of the additional weight gain than new muscle tissue. The practice of “mega dosing” is inefficient (not to mention potentially dangerous), especially when we take into account the typical high cost of Sustaxyl 350. Such use is usually not justified outside of aggressive bodybuilding regimens.
Sustaxyl 350 is rarely used with women in clinical medicine. When applied, it is most often used to induce masculinization in female to male transsexuals. Sustaxyl 350 is not recommended for women for physique- or performance-enhancing purposes due to its strong androgenic nature, tendency to produce virilizing side effects, and slow-acting characteristics (making blood levels difficult to control).