this is taken from the steroid profiles on steroid.com, sorry its a longish but tells you everything you need to know about tren.
"The drug trenbolone acetate is, without a doubt, the most powerful injectable anabolic steroid used by bodybuilders to gain muscle. However the full properties of the drug are not always fully understood. This profile will separate fact from fiction and help you decide if trenbolone is right for you.
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, and 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 (A.R), 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 A.R dependant mechanisms of muscle growth. There is also strong supporting evidence that compounds which bind very tightly to the androgen receptor also aid in fat loss. Think as 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 anti-anabolic (muscle destroying) glucocorticoid hormones (6). This may also 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 animals 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 diet adjusted, thus improving feed efficiency. Finding new compounds which 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 and under the skin. As if the report on trenbolone was 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 is that androgen receptors are found in fat cells as well as muscle cells(10), androgens act directly on the A.R in fat cells to affect fat burning.(11) the stronger the androgen binds to the A.R, the higher the lipolytic (fat burning) effect on adipose tissue (fat)(11). Since some steroids even increase the numbers of A.R in muscle and fat (11, 12) this fat loss 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, trenbolones 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.
Trenbolones chemical structure makes it resistant to the aromatize enzyme (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, ***** tits) accelerated fat gain, decline in fat break down and water retention trenbolone. Trenbolone is also resistant to the 5- alpha-reductase enzyme, this enzyme reduces some steroid hormones into a more androgenic form, in trenbolones case however this does not matter, trenbolone boasts an androgenic ratio of 500, it can easily cause adverse androgenic side effects in any steroid.com members who are prone cases of hair loss, prostate enlargement, oily skin and acne have been reported. Unfortunately trenbolones 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 steroid.com members this can lead to bloat and breast growth 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, as well as 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 which even a relatively small dose and keep the testosterone level suppressed for an extended period of time, this can lower libido and cause erectile dysfunction (fina ****). 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, coupled with a rapid clearing time the acetate ester can be discontinued on the onset of adverse side effects.
Evidence suggests that trenbolone when 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; trenbolones 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 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 it´s 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 thyroid level(23), and this raises prolactin. I recommend taking T3 (25mcgs/day) along with your Tren to avoid elevating your prolactin too high via this route.
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."
cheers
