Trenbolone acetate and Trenbolone enanthate

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Trenbolone Acetate

Trenbolone Profile
Note: this profile discusses the acetate and enanthate ester only. A separate profile for the cyclohexylmethylcarbonate / hexahydrobenzylcarbonate ester (Parabolan).

Trenbolone Acetate / Enanthate

(17beta-Hydroxyestra-4,9,ll-trien-3-one)   Of the anabolic androgenic steroids (AAS) used by body builders, trenbolone is considered by many to be the most remarkable. It has been a favored compound of body builders since its emergence on the BB scene in the 80’s, and advocates for this steroid can be borderline fanatical. But even within its devote following, trenbolone can be a love/hate relationship because of the severe side effects it is capable of.

The side effects, along with trenbolone’s appearance, disappearance and reappearance within the industry all lend to the mystique that seems to surround this drug.

Another factor that contributes to the’ tren mystique’ is the fact that there is very little scientific information available on the drug in regards to human consumption. Historically, trenbolone has been a product of the cattle industry, and as such, there is a plethora of exhaustive and in depth scientific studies to that end. However, the version of trenbolone that was created and approved for use by humans, Parabolan, did not stay in production long enough for any meaningful, long term studies to be conducted. Most of what we know about trenbolone’s effect on humans is derived from actual user experience, ‘bro’ science and folklore.


Trenbolone is a derivative of nandrolone (19-nor-testosterone) and is therefore a 19-nor steroid (testosterone molecule altered at the 19th position). Trenbolone differs in structure to nandrolone in that it has two additional double carbon bonds at positions 9 and 11.   While similar in structure, trenbolone shares little with it’s parent hormone. Like nandrolone, trenbolone is anti-estrogenic (a delta-9 group within its structure occupies a bond necessary for aromatization). Also, nandrolone is highly anabolic but is a poor androgen, whereas trenbolone excels in both categories and is much more anabolic and androgenic.   Both steroids have a strong affinity for binding with the androgen receptor.

Nandrolone’s ability to bind is approx. 2.4x stronger than testosterone, whereas trenbolone’s ability to bind is approx. 5x stronger, making it one of the most powerful injectable steroids ever produced on a commercial basis. As an androgen, trenbolone has a ratio index of 500 as compared to testosterone’s 100.   Another difference between the two is that trenbolone is 5-alpha reductase resistant, meaning that it’s strong receptor binding properties is not diminished in androgen sensitive tissues having high concentrations of 5AR, thus allowing the steroid to perform at its full potential.


Trenbolone first emerged in the late 60’s (1967) as a subject of study at the University of California In Los Angeles. It later went into production as a commercial product in the 70’s and was sold by Hoechst, a Brittish company (Finajet) and by Roussel in France (finaject) as an injectable acetate version.   The initial interest in the drug was veterinary in nature – to improve profitability in the cattle industry by way of feed efficiency. Feed efficiency is the term used for gaging increase in lean mass vs. feed consumed as well as overall increased weight. Trenbolone exhibits a superior propensity for converting food into lean mass. In the cattle business, food efficiency is a billion dollar industry and is where whey protein was first introduced.

What this means to a body builder is that the food you take in will be better utilized for adding lean mass as well as better vitamins, minerals and nutrient shuttling.   Feed effciency remains trenbolone’s primary purpose to this day. Cattle are treated with trenbolone up to the time they are slaughtered for market. Ordinarily, a cow will weigh approximately 500 lbs. at the time of slaughter, where as a similar cow that is treated with trenbolone will typically weigh as much as 750 lbs. when brought to the slaughter house. To a cattleman, this represents a 50% increase in profit.

The production of the veterinary products ended in 1987, probably as a result of the escalating controversy over athletic steroid use during this period. Even though the injectable forms were no longer manufactured, trenbolone acetate became available to the cattle industry about that same time in the form of solid pellets (Finaplix). The pellets were packaged in cartridges and administered to the cattle by a gun that would inject them into the ear. Because the pellet form made human consumption of the compound difficult, the product was made exempt to the normal laws governing steroids as controlled substances. The exemption, however, was mostly a result of marketability to its targeted audience – the cattle industry. Having exemption status meant that the product could be obtained and administered without the added cost of veterinary involvement.   The acetate version of trenbolone is often referred to as “Fina” in the steroid community because it was originally adapted for use as an injectable by users converting the Finaplix product (solid pellets) into an oil based solution.


Trenbolone is well known for its ability to produce high quality, dry muscle gains as well as greatly increasing strength. And, unlike other powerful AAS’s, such as Dianabol, gains realized from this compound are easy to maintain once the cycle ends. You are more likely to retain gains made during a trenbolone cycle than you are with most other steroids of similar potency.   Other benefits include hardness, lack of water retention, inability to convert into estrogen, increase fat burning/loss, improved definition and increased aggression. These benefits make it a popular choice of both competition and recreational body builders alike.

As a cutting steroid, trenbolone is second to none. This can be attributed to its powerful effect on nutrient partitioning. In the cattle industry, trenbolone has been proved highly effective at converting food into lean mass without increasing fat composition. In fact, studies show that trenbolone was actually almost too effective in this regard – treated cattle were almost too lean.

Another factor that contributes to trenbolone’s fat burning abilities is that is has such a high androgen ratio (ability to bind to the androgen receptor). Like muscle tissue, fat cells contain androgen receptors which, when stimulated by androgens, promote fat burning. The stronger the androgen’s ability to bind, the greater the effect is on fat burning.

And yet another reason trenbolone excels at fat loss is because of its anti-cortisol properties. Trenbolone binds quite well with the glucocorticoid receptor which allows it to decreases blood corticosteroid levels, making the steroid highly anti-catabolic. This also allows it to reduce subcutaneous water retention.

As a glucocorticoid (cortisol antagonist), trenbolone ranks well above all other mass gaining AAS’s.

Trenbolone Esters

Trenbolone has been manufactured using the acetate, enanthate and cyclohexylmethylcarbonate/ hexahydrobenzylcarbonate esters.


Since its introduction, Trenbolone has been commercially available as an acetate injectable in the form of Finajet (Brittish), Finaject (French version), Finaplix (an acetate in solid pellet form), and as Parabolan, a long ester designed for human consumption.

The production of the acetate injectables was discontinued in 1987 – probably as a result of the growing controversy regarding atheletic doping, thus ending it’s availability as a legal injectable until its more recent reappearance as a Ttokkyo product (Mexican lab).   Shortly after Hoechst and Roussel discontinued production, the drug re-emeged in the USA as Finaplix, whose targeted market was the cattle industry.

Trenbolone Cycle Use  

If this is your first experience with trenbolone, the short acetate ester is recommended in case side effects become intolerable. The cycle can be stopped and the short ester will clear the system quickly, allowing the side effects to subside shortly thereafter.   Acetate is a very short ester and works best if injected daily as opposed to every other day. Another consideration supporting the argument for daily injections is the severity of trenbolone’s side effects. Side effects can be triggered and further aggravated by the peaks and troughs of a steroid’s blood serum level. Daily administration insures the most consistent blood level possible with the acetate ester.   For enanthate, the recommended injection schedule is 2-3 times weekly.   People using enanthate will sometimes switch to the acetate ester towards the last weeks of the cycle. The transition from enanthate to acetate allows the user to continue to benefit from the steroid while facilitating a more rapid transition from the high levels needed for mass gain to low levels once the cycle is discontinued.


On a milligram comparison, trenbolone doses are lower than other popular injectables because of its potency. A little bit tends to go a long way.

Acetate – 50-75mg daily would be considered by many as the standard dosage for this ester but the practical effective dose among users can range from 35-150mg, with 50-100mg being typical.   For beginners: Because trenbolone side effects can be severe, people using the compound for the first time may want to start with a low dose and slowly work their way to higher doses once it has been determined that the side effects are tolerable.

A good dosage to start with would be 35mg daily for 2-3 weeks. If the side effects are manageable after this period, the user can increase the dosage to 50mg and perhaps higher, even.   100mg daily has been proven as an optimal dosage in regards to mass gain and strength increases. However, users will utilize higher doses (150mg) in order to amplify trenbolones other benefits, which tend to increase proportionally with the higher milligrams. People who are sensitive to the drug’s side effects should use the lowest recommended dosage – 35mg daily. Anything lower than this amount is frivolous since no practical benefit from the drug will be realized.

Enanthate – weekly dosage among users can range between 300-800mg, with 400-600mg being typical.   It should be noted that the weekly total dosage amount for enanthate will always be higher than acetate because of the molecular weight difference between the two esters. Trenbolone Enanthate contains 20% less of the active steroid for the same volume as it’s acetate version.

Stacking  – Trenbolone only cycles are not recommended for a couple of reasons. While significant gains can be realized using trenbolone alone, the compound really shines when stacked with testosterone. It is particularly effective with Anadrol or Dianabol.   Another reason trenbolone should be stacked with other compounds is because of estradiol issues. Not only does trenbolone not convert into estradiol (aromatise ), but at the same time, it suppresses the body’s natural production of testosterone, which is the source of estradiol in men. This means that a user may actually experience an unacceptable decrease in estrogen levels that can lead to problems with libido, joints and mood. Stacking trenbolone with another steroid that has a high estrogen conversion rate will prevent this situation. HCG and other compounds can be used during the cycle to prevent estrogen related issues.

First hand accounts from users indicate that trenbolone does not stack well with Anavar (oxandrolone), Primobolan (methenolone) or Masteron (drostanolone) for mass building purposes. Combining these steroids with trenbolone does not improve gaining lean mass over using trenbolone alone at the same milligram dosage. Still, these compounds can be included in a trenbolone stack in order to utilize their other benefits.   Because of its high androgen ration and inability to convert into estradiol, trenbolone makes for an exceptional cutting and hardening agent. For cutting purposes, a stack of trenbolone acetate, winstrol and testosterone proprionate has proven very effective. One reason for this is that the stack includes compounds from the three major anabolic families (testosterone, 19-nor, DHT). Each of these steroids has a different AR-binding affinity and works through different anabolic mechanisms.

Tren Side Effects 

Trenbolone’s side effects can be vicious and have added to the drug’s notoriety every bit as much as it’s incredible ability to produce quality mass and strength. The side effects include lethargy, coughing (tren cough), shortness of breath, indigestion, elevated aggression, unusual dreams, night sweats, day sweats, anxiety, reduced sexual performance, erectile dysfunction and obstructed cardio performance.   Trenbolone is a 19-nor compound which means it has the tendency to lower thyroid levels. Lower thyroid levels increases prolactin levels. Higher prolactin levels can possibly cause erectile dysfunction (fina dick) in some users. Products such as cabergoline can be used to lower these levels and keep them in check. Also, T3 may be used during the cycle to prevent the prolactin elevation.

Trenbolone is considered a poor drug of choice for athletes and others who are involved in cardio intensive activities since the drug is notorious for reducing endurance levels.   As with any steroid usage, it is recommended that bloodwork be performed during the cycle. In trenbolone’s case, it would be wise to keep a close watch on cholesterol levels, especially if using the steroid for excessively long periods. Trenbolone has been known to affect cholesterol levels, as well as kidney function and liver enzymes in some individuals.   With its high androgenic ratio, trenbolone is more than capable of producing the adverse side effects typically associated with AAS’s. This includes hair loss (for people predisposed to male pattern baldness), prostate enlargement, testicular atrophy, oily skin and acne.

Trenbolone is reported to be especially hard on the HTPA function (Hypothalamus-Pituitary-Testes-Axis) so the use of Clomid/Nolvadex and HCG is highly recommended during a trenbolone cycle to prevent possible testicular atrophy. Accutane can be used to treat steroid related acne and DHT blockers such as rogaine may lessen or prevent hair loss.


Liver Toxicity  – It was at one time believed that trenbolone was toxic to the kidneys. This is a fact that has never been proven in the scientific community and the myth is probably a result of urine excretion of the drugs rust colored metabolites. Gyno Trenbolone is frequently blamed for causing of gyno even though there is no direct evidence supporting this allegation. This notion may be the result of findings from studies performed on bovine. The studies indicate that trenbolone has a strong affinity for binding with the progestine receptor, a trait also found with nandrolone but to a lesser degree.

Trenbolone itself binds to the receptor with about 60% the actual effectiveness as progesterone (the female sex hormone) itself. In it’s active metabolite form, 17beta-trenbolone, its ability to bind is even stronger than progesterone’s. Even though this is the case, the fact remains that trenbolone’s progestational influence within humans is simply too insignificant to support the idea that the compound causes gyno.   It may be plausible, though, to consider the possibility that trenbolone has an indirect influence in some gyno cases, for example: trenbolone has an exceptional ability to bind with the progestine receptor. Progesterone is believed to enhance estrogen’s stimulation of mammary gland growth. It may be through this estrogenic enhancement that trenbolone, when used with other aromatizable compounds such as dianabol, could possibly contribute to gyno. Again, there is no direct evidence to support this theory.

Chemical Makeup

Trenbolone Acetate (17beta-Hydroxyestra-4,9,11-trien-3-one)   Formula: C20 H24 O3  Molecular Weight base / ester: 270.3706 / 60.0524 total = 312.4078  Formula – base / ester: C18 H22 O2 / C2 H4 O2  Melting Point base/ester: 183-186C / 16.6C  Effective Dose: 50-150mg ED  Active life – acetate: 2-3 days  Active life – enanthate: 5 days  Detection Time: 5 months.

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One comment on “Trenbolone acetate and Trenbolone enanthate

  1. bigrobbie says:

    Ok folks…this blog isn’t too bad. Now I’ll be the first to say if an article or blog sux…however he did ok on this one.

    I do think he should have provided references as well as maybe given at the very least a rough description on the way we used to convert finaplix to injectable tren.

    Other than that, I think this is a fairly informative article.


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