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Trenbolone Acetate

Trenbolone Base with Acetate Ester

Formula (ester): C2 H4 02
Molecular Weight: 312.4078
Molecular Weight (base): 270.3706
Molecular Weight (ester): 60.0524
Melting Point (base): 183-186C
Melting Point (ester):16.6C
Manufacturer: Cattle implants, British Dragon, Various
Release Date (United States): 1987
Effective Dose (Men):50-150mg ED
Effective Dose (Women): Not recommended
Active life: 2-3 days
Detection Time: 5 months
Anabolic/Androgenic ratio: 500/500

The drug trenbolone is, without a doubt, the most powerful injectable anabolic steroid used by athletes to gain muscle. However the full properties of the drug are not always fully understood. This profile will separate fact from fiction and help athletes decide if trenbolone is right for them.
Trenbolone is similar to the highly popular steroid nandrolone, in that they are both 19-nor steroids, meaning that a testosterone molecule has been altered at the 19th position to give us a new compound. Unlike nandrolone however, trenbolone is an excellent mass and hardening drug with the majority of gains being muscle fiber, with minimal water retention (1). It has an unbelievable anabolic (muscle building) score of 500. When you compare that to testosterone, which itself is a powerful mass builder but has an anabolic score of 100, you can begin to fathom the muscle building potential of trenbolone. What makes trenbolone so anabolic? Numerous factors come into play. Trenbolone greatly increases the level of the extremely anabolic hormone IGF-1 within muscle tissue (2). And, it’s worth noting that not only does it increase the levels of IGF-1 in muscle over two fold, it also causes muscle satellite cells (cells that repair damaged muscle) to be more sensitive to IGF-1 and other growth factors (3). The amount of DNA per muscle cell may also be significantly increased (3).
Trenbolone also has a very strong binding affinity to the androgen receptor (AR), binding much more strongly than testosterone (4). This is important because the stronger a steroid binds to the androgen receptor, the better that steroid works at activating AR dependant mechanisms of muscle growth. There is also strong supporting evidence that compounds binding very tightly to the androgen receptor also aid in fat loss. Think of the receptors as locks and androgens as different keys, with some keys (androgens) opening (binding) the locks (receptors) much better than others. This is not to say that AR-binding is the final word on a steroid’s effectiveness. Anadrol doesn’t have any measurable binding to the AR, and we all know how potent Anadrol is for mass-building.
Trenbolone increases nitrogen retention in muscle tissue (5). This is of note because nitrogen retention is a strong indicator of how anabolic a substance is. However, trenbolone’s incredible mass building effects do not end there. Trenbolone has the ability to bind with the receptors of the catabolic (muscle destroying) glucocorticoid hormones (6) giving it anti-catabolic properties as well. This has the effect of inhibiting the catabolic (muscle destroying) hormone cortisol (7).
Yet another amazing trait of trenbolone that must be noted is its ability to improve feed efficiency and mineral absorption in animals given the drug (8). To help you understand what this means for you, feed efficiency is a measurement of how much of an animal’s diet is converted into meat, and the more food it takes to produce this meat, the lower the efficiency. Conversely, the less food it takes to produce meat, the higher the efficiency—well you get the idea. Animals given trenbolone gained high quality weight without having their diets adjusted, thus improving feed efficiency. Finding new compounds that can improve feed efficiency is a billion dollar industry, and has spawned many nutritional advances in the bodybuilding world over the last few decades (CLA, Whey Protein, and HMB are compounds which spring to mind as having first been introduced by the livestock industry). What does this translate to for the hard training athlete? The food you eat will be better utilized for building lean muscle, and vitamins and minerals are also better absorbed, which may keep you healthier during cycle.

Trenbolone is also a highly androgenic hormone, when compared with testosterone, which has an androgenic ratio of 100; trenbolone’s androgenic ratio is an astonishing 500. Highly androgenic steroids are appreciated for the effects they have on strength as well as changing the estrogen/androgen ratio, thus reducing water under the skin. As if the report on trenbolone were not good enough, it gets better; trenbolone is extraordinarily good as a fat loss agent. One reason for this is its powerful effect on nutrient partitioning (9). It is a little known fact that androgen receptors are found in fat cells as well as muscle cells (10). Androgens act directly on the AR in fat cells to affect fat burning (11). The stronger the androgen binds to the AR, the higher the lipolytic (fat burning) effect on adipose tissue (fat) (11). Since some steroids even increase the numbers of AR in muscle and fat (11)(12), this lypotropic (fat losing) effect would be amplified with the concurrent use of other compounds, such as testosterone.
Trenbolone promotes red blood cell production and increases the rate of glycogen replenishment, significantly improving recovery (13). Like almost all steroids, trenbolone’s effects are dose dependant with higher dosages having the greatest effects on body composition and strength. Mental changes are a notorious side effect of trenbolone use (15); androgens increase chemicals in the brain that promote aggressive behavior (16), which can be beneficial for some athletes wanting to improve speed and power.

Unwanted Effects
Trenbolone’s chemical structure makes it resistant enzymes that aromatize (conversion to estrogen), thus absolutely no percentage of trenbolone will convert to estrogen. Trenbolone administration would not promote estrogenic side effects such as breast tissue growth in men (gynecomastia, bitch tits) accelerated fat gain, decline in fat break down and water retention. Trenbolone is also resistant to the 5- alpha-reductase enzyme; this enzyme reduces some steroid hormones into a more androgenic form. In trenbolone’s case however this does not matter, trenbolone boasts an androgenic ratio of 500, and it can easily cause adverse androgenic side effects. In any athletes who are prone to cases of hair loss, prostate enlargement, oily skin and acne have been reported. Unfortunately trenbolone’s potential negative side effects do not end there. Trenbolone is also a noted progestin: it binds to the receptor of the female sex hormone progesterone (with about 60% of the actual strength progesterone) (17). In sensitive athletes, this can lead to bloat and breast growth or worse still, trenbolones active metabolite17beta. Trenbolone has a binding affinity to the progesterone receptor (PgR) that is actually greater than progesterone itself (18). No need to panic though, the anti-estrogens Letrzole or Fulvestrant can lower progesterone levels, and combat any progestenic sides. The use of a 19-nor compound like trenbolone also increases prolactin. Bromocriptine or cabergoline are often recommended to lower prolatin levels (20). Testicular atrophy (shrunken balls) may also occur; HCG used intermittently throughout a cycle can prevent this (21). It is also wise for Tren users to closely monitor their cholesterol levels, kidney function, and liver enzymes as Tren has the potential to negatively affect all of those functions. Trenbolone, being a powerful progestin, will also shut down natural testosterone production—even a relatively small dose will keep the testosterone level suppressed for an extended period of time. This can lower libido and cause erectile dysfunction (fina dick). It is essential that you always stack trenbolone with testosterone.
The acetate ester is a very short-chain ester attached to the trenbolone molecule. It has an active life of 2-3 days but to keep blood levels of trenbolone elevated and steady, daily injections are often recommended. The acetate ester provides a rapid and high concentration of the hormone, which is beneficial to those seeking quick gains. When coupled with a rapid clearing time, the acetate ester can be discontinued on the onset of adverse side effects.
Now that the properties of trenbolone acetate have been explained, we can better understand how to use it in order to maximize its advantages. Evidence suggests that trenbolone stacked with estrogen promotes more weight gain that trenbolone alone (22). Now I’m not telling you to go pop some birth control with your trenbolone, but the addition of aromatizing orals such as Dianabol and a long estered testosterone such as cypionate or enanthate would produce great gains in a bulking cycle. For a cutting cycle, trenbolone is the best choice you have; trenbolone’s powerful effect on nutrient shuttling allows a user to restrict calories and remain in a state of positive nitrogen balance (remember what that means?). The cortisol reducing effect, and its binding to the glucocorticoid receptor will greatly reduce the catabolic effects of harsh dieting and excessive amounts of cardio, not to mention that trenbolone itself may burn fat (due to its strong AR-binding). A good choice to stack with Tren in a cutting cycle is Winstrol. Winstrol has a low binding affinity to the AR and thus will act in your body in vastly different ways than the Tren (i.e. in non-receptor mediated action). In addition, Winstrol is a DHT-based drug and Tren is a 19-nor. Throw in some Testosterone (prop), and you’ll have a cutting cycle which takes advantage of all 3 major families of Anabolic Steroids (Testosterone, 19-nor, and DHT), as well as vastly different AR-binding affinities and mechanisms of action.
Ironically, even though Tren is an excellent contest prep drug, it lowers your thyrold level (this, by means of the body’s negative-feedback-loop, also raises prolactin). I recommend taking T3 (25mcgs/day) along with your Tren.
Also, this drug is a poor choice for athletes who rely on cardiovascular fitness to play a sport. Tren, anecdotally at least, reduces many athletes’ ability to sustain high levels of endurance. Unfortunately, this makes Tren a poor choice for many.

As of now the main source of trenbolone is from implants for cattle being converted into an injectable or transdermal compound, from powder, and of course underground labs. “Home brewing” powder or cattle implants seems to be the preferred method of obtaining injectable trenbolone acetate, because the user would have much more control over the potency and sterility of the drug. Trenbolone is much more expensive than other anabolic steroids ranging from. The cost of trenbolone should not matter—it is worth every penny.

1. Br J Nutr. 1978 Nov;40(3):563-72.
2. J Cell Physiol. 2004 Nov;201(2):181-9.
3. Endocrinology. 1989 May;124(5):2110-7.
4. Toxicol Sci. 2002 Dec;70(2):202-11.15
5. J Anim Sci. 1994 Feb;72(2):515-22.
6. APMIS. 2001 Jan;109(1):1-8.
7. J Anim Sci. 1990 Sep;68(9):2682-9.
8. APMIS. 2001 Jan;109(1):1-8.
9. J Anim Sci. 1992 Nov;70(11):3381-90.
10. Am J Physiol. 1998 Jun;274(6 Pt 1):C1645-52.
11. Biochim Biophys Acta. 1995 May 11;1244(1):117-20.
12. J Appl. Physiol.94 1153-61 2003
13. J Vet Med A Physiol Pathol Clin Med. 2001 Aug; 48(6):343-52
14. Toxicol Sci. 2002 Dec;70(2):202-11.15
15. On-line forums.
16. Med Sci Sports Exerc. 2003 Jan; 35(l):32-8
17. Cancer Res 1978 Nov; 38(11 Pt 2):4186-98
18. APMIS. 2000 Dec;108(12):838-46.
19. Curr Med Res Opin. 2001;16(4):276-84
20. 2003 drug handbook.
21. Pharmacol Biochem Behay. 1988 Mar; 29(3):489-93.
22. J Anim Sci. 1997 May;75(5):1256-65.