This is a bit outdated on the info as PARA is available now and has been sometime just not under the NEGMA label but a good read non the less.
Pesonally I (wouldn't) go over 3-400 mg of any tren ester per week as it is very powerful and potent in those ranges but many test the upper eschelon of doses which really potentiates the sides and damage IMO with out an equal return in gains.
"Parabolan® (trenbolone hexahydrobenzylcarbonate)
This item was produced by Negma in France, and for some time was the last remaining injectable worldwide that contained the extremely potent steroid trenbolone. It was discontinued in 1997 however, and currently no real Parabolan can be found on the black market. This profile is still included for interest value, plus to help you understand the variety of Parabolan fakes that are still out there.
You may associate trenbolone with the long deceased Finajet, a veterinary steroid that was popular in the United States during the 1980's. Finajet contained trenbolone acetate, which was a very fast acting form of this drug (see: trenbolone acetate). Parabolan contains a much different ester, trenbolone hexahydrobenzylcarbonate. This ester extends the activity of the drug for more than two weeks, a more suitable design for human use. Parabolan is packaged only in ampules of l.5ml, one ampule per a box. Each ampule contains 76mg of trenbolone hexahydrobenzylcarbonate, equivalent to 50mg of trenbolone base (French drugs commonly make this calculation).
Trenbotone is a very potent androgen with strong anabolic activity. It is well suited for the rapid buildup of strength and muscle mass, usually providing the user exceptional results in a relatively short time period. The anabolic effect of this drug is often compared to popular bulking agents such as testosterone or Dianabol, with one very important difference. Trenbolone does not convert to estrogen. This is indeed a very unique compound since mass drugs, almost as a rule, will aromatize (or cause other estrogen related troubles) heavily. When we think of taking milder (regarding estrogen) steroids we usually expect much weaker muscle growth, but not so with Parabolan. Here we do not have to worry about estrogen related side effects, yet still have an extremely potent mass/strength drug. There is no noticeable water retention, so the mass gained during a cycle of Parabolan will be very hard and defined (providing fat levels are low enough). Gynecomastia is also not much of a concern, so there shouldn't be any need to addition an antiestrogen if trenbolone is the only steroid administered.
The high androgen level resulting from this steroid, in the absence is excess estrogen, can also accelerate the burning of body fat. The result should be a much tighter physique, hopefully without the need for extreme dieting. Parabolan can therefore help bring about an incredibly hard, ripped physique and is an ideal product for competitive bodybuilders. This is of course no secret, and when available on the market, Parabolan was the most sought after contest preparation drug. Now this it is no longer produced, acceptable substitutes for this purpose include of course veterinary trenbolone acetate preparations, as well as Halotestin®, Proviron® and Masteron (also recently discontinued).
Trenbolone is notably more potent than testosterone, and has an effect that is as much as three times as strong on a milligram for milligram basis. Likewise we can expect to see some level of androgenic side effects with use of this compound. Oily skin, aggressive behavior, acne and hair loss are therefore not uncommon during a cycle with this steroid. The androgenic nature of this drug of course makes it a very risky item for women to use, the chance for virilization symptoms extremely high with such a potent androgen. And since the hexahydrobenzylcarbonate ester will extend the activity of this drug for weeks, blood levels can be very difficult to control. Since many of the masculinizing side effects associated with steroid use can be permanent, women considering the use of this compound should take extreme caution. It can be weeks before blood levels decline should a problem become evident.
Trenbolone is also much more potent than testosterone at suppressing endogenous androgen production. This makes clear the fact that estrogen is not the only culprit with negative feedback inhibition, as here there is no buildup of this hormone to report here. There is however some activity as a progestin inherent in this compound, as trenbolone is a 19-nortestosterone (nandrolone) derivative (a trait characteristic of these compounds). However it seems likely that much of its suppressive nature still stems from its powerful androgen action. With the strong impact trenbolone has on endogenous testosterone, of course the use of a stimulating drug such as HCG and/or Clomid®/Nolvadex® is recommended when concluding steroid therapy (a combination is preferred). Without their use it may take a prolonged period of time for the hormonal balance to resume, as the testes may at first not be able to normally respond to the resumed output of endogenous gonadotropins due to an atrophied state. Those who have used Parabolan regularly would often claim it to be indispensable. A weekly dosage of 3 ampules (228mg) was the most popular range when running a cycle, however many did find it highly effective in lesser amounts. Although a weekly administration schedule would prove sufficient, athletes usually injected a single ampule per application, the total amount spread evenly throughout the week. While Parabolan is quite potent when used alone, it was generally combined with other steroids for an even greater effect. Leading up to a show one could successfully add a non-aromatizing anabolic such as Winstrol® or Primobolan®. Such combinations will elicit a greater level density and hardness to the build, often proving dramatic to a stage appearance. We could also look for bulk with this drug, and addition stronger compounds like Dianabol or Testosterone. While the mass gain would be quite formidable with such a stack, some level of water retention would probably also accompany it. Moderately effective anabolics such Deca-Durabolin® or Equipoise® would be somewhat of a halfway point, providing extra strength and mass but without the same level of water bloat we see with more readily aromatized steroids."