Sten — testosterone cypionate & propionate

Sten is a two-component testosterone blend from Mexico that contains a mixture of testosterone propionate (25 mg), testosterone cypionate (75 mg), and DHEA (dehydroepiandrosterone; 20 mg) in a 2 mL ampule. Some references incorrectly list this product as containing 20 mg of DHT (dihydrotestosterone), which would be a third androgen. This is, however, just a confusion of the Spanish word for DHEA (dehidroisoandrosterona), which at a quick glance looks similar to “dihydrotestosterona.” More recent packaging lists this ingredient as the less confusing “prasterona”(prasterone; another accepted term for DHEA). Holding the DHEA irrelevant at the moment, this steroid product contains a simple 50 mg/ml mixture of two common testosterone esters. Many consider Sten to be a low-budget alternative to Sustanon 250. While it does contain a blend of two testosterone esters, Sten is not as slow-acting in comparison. The longest ester of testosterone it uses is cypionate, which allows testosterone levels to return to baseline approximately 2 weeks after injection. Testosterone cypionate is also not a delayedonset drug, so Sten doesn’t offer much advantage in regards to a “sustained-release” effect. The testosterone propionate only compounds the initial testosterone spike, making its pharmacokinetic profile more uneven than if testosterone cypionate were used alone. Of course Sten and Sustanon are both testosterone products, so given equivalently dosed weekly injections the end result should not be very different between the two.

Brand name Sten, Testosterone cypionate & propionate
Androgenic 100
Anabolic 100
Standard Standard
Chemical Names 4-androsten-3-one-17beta-ol
Estrogenic Activity moderate
Progestational Activity low

Sten History

Sten is made in Mexico by the pharmaceutical firm Atlantis, S.A. de C.V. This agent is used primarily to correct low androgen levels in males, for the treatment of hypogonadism, andropause, and impotence. It is also sometimes prescribed to women for excessive lactation, advanced breast cancer, and low sex drive. Sten has a long history of sale on the Mexican market, where it is one of the country’s more inexpensive human-use testosterone products. It has consequently remained a somewhat popular item there, even if its formulation may not be the most properly suited for the higher-dosed requirements of athletic use.

How is Sten Supplied

Sten is available on the human drug market in Mexico. It contains a blend of 25 mg/75 mg testosterone propionate and testosterone cypionate (respectively) per 2-milliliter ampule.

Structural Characteristics of Sten

Sten contains a mixture of two testosterone compounds, which where modified with the addition of carboxylic acid esters (propionic and cyclopentylpropionic 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. Sten is designed to provide a rapid peak in testosterone levels (24-48 hours after injection), and maintain physiological concentrations for approximately 14 days.

Sten Side Effects (Estrogenic)

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 antiestrogen 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.

Sten Side Effects (Androgenic)

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.

Testosterone Cypionate & Propionate Side Effects (Hepatotoxicity)

Testosterone does not have hepatotoxic effects; liver toxicity is unlikely. One study examined the potential for hepatotoxicity with high doses of testosterone by administering 400 mg of the hormone per day (2,800 mg per week) to a group of male subjects. The steroid was taken orally so that higher peak concentrations would be reached in hepatic tissues compared to intramuscular injections. The hormone was given daily for 20 days, and produced no significant changes in liver enzyme values including serum albumin, bilirubin, alanine-amino-transferase, and alkaline phosphatases.

Testosterone Cypionate & Propionate Side Effects (Cardiovascular)

Anabolic/androgenic steroids can have deleterious effects on serum cholesterol. This includes a tendency to reduce HDL (good) cholesterol values and increase LDL (bad) cholesterol values, which may shift the HDL to LDL balance in a direction that favors greater risk of arteriosclerosis. The relative impact of an anabolic/androgenic steroid on serum lipids is dependant on the dose, route of administration (oral vs. injectable), type of steroid (aromatizable or non-aromatizable), and level of resistance to hepatic metabolism. Anabolic/androgenic steroids may also adversely effect blood pressure and triglycerides, reduce endothelial relaxation, and support left ventricular hypertrophy, all potentially increasing the risk of cardiovascular disease and myocardial infarction.

Testosterone tends to have a much less dramatic impact on cardiovascular risk factors than synthetic steroids. This is due in part to its openness to metabolism by the liver, which allows it to have less effect on the hepatic management of cholesterol. The aromatization of testosterone to estradiol also helps to mitigate the negative effects of androgens on serum lipids. In one study, 280 mg per week of testosterone ester (enanthate) had a slight but not statistically significant effect on HDL cholesterol after 12 weeks, but when taken with an aromatase inhibitor a strong (25%) decrease was seen. Studies using 300 mg of testosterone ester (enanthate) per week for twenty weeks without an aromatase inhibitor demonstrated only a 13% decrease in HDL cholesterol, while at 600 mg the reduction reached 21%. The negative impact of aromatase inhibition should be taken into consideration before such drug is added to testosterone therapy.

Due to the positive influence of estrogen on serum lipids, tamoxifen citrate or clomiphene citrate are preferred to aromatase inhibitors for those concerned with cardiovascular health, as they offer a partial estrogenic effect in the liver. This allows them to potentially improve lipid profiles and offset some of the negative effects of androgens. With doses of 600 mg or less per week, the impact on lipid profile tends to be noticeable but not dramatic, making an anti-estrogen (for cardioprotective purposes) perhaps unnecessary. Doses of 600 mg or less per week have also failed to produce statistically significant changes in LDL/VLDL cholesterol, triglycerides, apolipoprotein B/C-III, C-reactive protein, and insulin sensitivity, all indicating a relatively weak impact on cardiovascular risk factors. When used in moderate doses, injectable testosterone esters are usually considered to be the safest of all anabolic/androgenic steroids.

To help reduce cardiovascular strain it is advised to maintain an active cardiovascular exercise program and minimize the intake of saturated fats, cholesterol, and simple carbohydrates at all times during active AAS administration. Supplementing with fish oils (4 grams per day) and a natural cholesterol/antioxidant formula such as Lipid Stabil or a product with comparable ingredients is also recommended.

Sten Side Effects (Testosterone Suppression)

All anabolic/androgenic steroids when taken in doses sufficient to promote muscle gain are expected to suppress endogenous testosterone production. Testosterone is the primary male androgen, and offers strong negative feedback on endogenous testosterone production. Testosterone-based drugs will, likewise, have a strong effect on the hypothalamic regulation of natural steroid hormones. Without the intervention of testosterone-stimulating substances, testosterone levels should return to normal within 1-4 months of drug secession. Note that prolonged hypogonadotrophic hypogonadism can develop secondary to steroid abuse, necessitating medical intervention.

Sten Administration (General)

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.

Sten Administration (Men)

For the treatment of low androgen levels, the prescribing guidelines for Sten recommend one injection of one 2 mL ampule (100 mg testosterone esters; 20 mg DHEA) every 15-30 days. For bodybuilding purposes, this drug is usually injected on a weekly basis, in a dosage of 2-4 ampules (200-400 mg of testosterone esters in total). This level is sufficient to provide excellent gains in muscle size and strength. Higher doses are possible, but even the injection volume needed with 4 ampules per week (8ml) can become too uncomfortable for many. Testosterone drugs are ultimately very versatile, and can be combined with many other anabolic/androgenic steroids depending on the desired effect.

Sten Administration (Women)

The prescribing guidelines for Sten do not make special dosing recommendations for women, except to say that androgenic symptoms may occur, and in certain scenarios therapy should be suspended until symptoms resolve, and after a lower dose used. This drug 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).

Sten Availability

Sten is commonly found in Mexico, where 2 pre-loaded syringes are packaged in a box and usually sell for about $10 in the pharmacy.

Anabolic Steroid Guide reference

This is another multi-component testosterone which is becoming increasingly popular. Although the substance combination is not the same, this remedy can definitely be compared to Sustanon. The total quantity of the substance corresponds to just slightly less than half of the quantity included in Sustanon and therefore, either more frequent or more voluminous injections of Sten are necessary. The characteristics of Sten will not be discussed in detail since the de-scription would be almost identical to that found in the chapter "Sustanon." We currently do not know of any fakes of this com-pound. Sten is available for $30 on the black market. At this price, however, one receives 2 Redi-ject injections which seem to be worth the money The 2 ml ampule has a brownish-red imprint which cannot be scratched off and is easily felt, having been burnt into the glass. Two ampules together with a 3 ml syringe and its needle are packaged in a plastic bed.

Newbies Research Guide reference

Description: 120 mgs. / ampule. 100 mgs. being testosterone and 20 mgs. being DHEA. Sten is an androgenic drug that is good for strength and size. It is made up of two drugs; the first is testosterone suspended in oil, the second is DHEA. This is just a weaker version of Sostenon 250. The side effects associated with it are a little worse because of the high amount of DHT in it. It is picking up in popularity since it is easy to attain in Mexico.
Effective Dose: 3 - 4 ampules per week
Street Price: $15 / ampule
Stacking Info: Could be used in a bulking cycle but you have to take more shots of the stuff since it is only available in lower mgs. doses.


Wlliam Llewellyn (2011) - Anabolics
Anabolic Steroid Guide
Newbies Research Guide

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