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Sustanon: Down With the King?


By William Llewellyn



This week I’d like to talk about Sustanon 250, the widely popular multi-ester testosterone blend developed and sold by international drug giant Organon. For those unfamiliar, Sustanon 250 is an injectable testosterone preparation that uses four different esters of testosterone mixed in different concentrations. Specifically, each milliliter of oil contains testosterone propionate (30 milligrams), testosterone phenylpropionate (60 milligrams), testosterone isocaproate (60 milligrams) and testosterone decanoate (100 milligrams), for a total dose of 250 milligrams.


The design uses different esters with different release patterns, which are supposed to work synergistically to provide a rapid, yet evenly sustained, elevation of testosterone levels for up to a month. Depending on the prescribing recommendations, the drug is usually administered once every three to four weeks in a clinical setting and is believed by many (patients and bodybuilders alike) to be a much more “engineered” form of injectable testosterone than enanthate or cypionate.


Setting the Stage


Sustanon 250 first appeared on international drug markets during the early 1970s, decades after enanthate and cypionate had become the standard forms of testosterone therapy. The “newness” of this drug must have caught the attention of the average bodybuilder when it was first released, especially given the very exotic blend of different testosterones it carried. The ‘70s were a crazy time in the steroid world. The markets were flooded with a variety of different drugs, most developed during the ‘50s and ‘60s, and there was a lot to choose from. Sustanon 250 came in on the back of a very active market, but also a slightly older one. With Organon behind it, Sustanon 250 was promising to raise testosterone injections to a whole new level of convenience and comfort. The public bought into the new technology very quickly and Sustanon 250 was soon in very high demand.


The mystique of Sustanon grew during the 1980s and 90s, partly due to its very good reviews. In the Underground Steroid Handbook II, Dan Duchaine commented on Sustanon:


This time-release testosterone injection was designed by Organon to give an even release of testosterone over a month’s time. Athletes inject Sustanon 250 at least once a week. This is a very popular testosterone and preferred by bodybuilders over testosterone cypionate and enanthate … it doesn’t seem to show as much water retention as cypionate.”


Bill Phillips would go on to describe it as a drug with four different steroids to target four different steroid receptors in his Anabolic Research Guide (we won’t fault Bill too much), and the World Anabolic Review would mention, “Sustanon 250, milligram for milligram, has a better effect than testosterone enanthate, cypionate and propionate.” With press like this, its popularity in the bodybuilding world was all but guaranteed.


Steady-state Pharmacokinetics


Although some researchers have strong feelings about trying to mimic the circadian rhythm of testosterone release in normal males, with high and low periods during each 24-hour period, steady-state pharmacokinetics is considered the goal of testosterone replacement therapy. This refers to the maintenance of a steady level of hormone in the blood day after day, so the patient is faced with a predictable and constant response from the medication and not regular periods of supraphysiological (high) or subphysiological (low) levels. At the time, the closest things to steady-state pharmacokinetics with testosterone were surgical implant pellets, which dissolve in a steady and predictable (though still not perfectly even) pattern over several months. All early hopes were that Sustanon 250 would come close to steady-state pharmacokinetics and relegate other injectable testosterones – with their peaks and troughs – to a state of obsolescence. This has always been its key selling point.




By the end of the 1990s, Sustanon 250 was being called by many the “king of all testosterones.” It was considerably more expensive than testosterone enanthate or cypionate, and yet was one of the most sought after testosterone products on the international black market due to its perceived balanced delivery. It still is today. But is it justified? The answer, surprising to some I’m sure, is no. I myself have long been an advocate of enanthate or cypionate, based mainly on the amount of testosterone you get dollar for dollar, and the frequent (weekly) injection schedule it’s usually used with. After all, why pay more for a drug you can take once every four weeks if you’re going to use it weekly anyway? But the arguments against Sustanon go well beyond a mere testosterone-per-dollar calculation. It turns out that even in a clinical setting, Sustanon may not provide the slow and steady hormone release it’s always promised.


Adding Fire to Fire


Sustanon was designed on a simple premise: mixing fast- and slow-acting esters in one injection will allow for a more balanced delivery throughout the full therapeutic window. In this formula we basically have one long-acting ester (decanoate), which accounts for 100 milligrams of the formula and three much faster-acting esters. As one would surmise, the shorter esters are to provide a more rapid effect during the first weeks of therapy, while the decanoate would hobble its way into the bloodstream during the latter weeks. Together, they reach a balance. In theory, this seems sound, until we look at the pharmacokinetics of a decanoate injectable. Below is a graph displaying the release pattern of nandrolone following nandrolone decanoate intramuscular injection. The peak hormone level is reached approximately 48 hours after the drug is given, not weeks.



Chem Corner 1

Source: Pharmacokinetic parameters of nandrolone (19-nortestosterone) after intramuscular administration of nandrolone decanoate (Deca-Durabolin®) to healthy volunteers. Wijnand H, Bosch A, Donker C. Acta Endocrinol 1985 supp 271 19-30.

On close analysis of the individual esters, the pharmacokinetic properties of Sustanon aren’t as ideal as initially described. If testosterone decanoate isn’t a delayed-onset drug as thought, but actually provides a peak in testosterone 48 hours after administration, what’s going to happen to the other fast-acting esters? The answer is simple. Adding fast-acting esters like testosterone propionate, phenylpropionate and isocaproate to a formulation of testosterone decanoate is only going to compound the initial testosterone spike. In a clinical setting, this is one of the key drawbacks to testosterone enanthate and cypionate injections. Levels spike the first several days and then decline, forcing the patient to endure the highs and lows between each application. Sharpening this early testosterone peak will give us an even greater imbalance between the early and latter days of the administration window.


In Closing


So where does this leave our most famous testosterone blend? Ultimately, I think it calls for a new assessment of this drug, both in the bodybuilding and hormone replacement community. What was billed as a slow-steady hormone replacement option has turned out to be anything but. While Sustanon may offer the advantage of less frequent injections than enanthate, the patient is going to pay for this with a much more imbalanced therapeutic window. Athletes should, likewise, no longer consider Sustanon the “slow-steady” testosterone. In essence, it’s simply a “tweaked” form of enanthate; a little sharper immediately after injection, but for all intents and purposes, equivalent when given on a weekly basis and less advantageous with wider dosing windows. Sustanon and enanthate both provide plenty of testosterone and both work absolutely fine. However, it just seems unnecessary to pay the extra for Sustanon.


William Llewellyn is widely regarded as one of the world’s foremost authorities on the use of performance-enhancing substances. He is the author of the bestselling anabolic steroid reference guide ANABOLICS and CEO of Molecular Nutrition. William is an accomplished researcher/developer in the field of anabolic substances, and is also a longtime advocate for harm reduction and legislative change. He built the website, an extensive online database of information on anabolic steroids and other performance-enhancing drugs.