You may notice that many injectable steroids will list long chemical names like testosterone cypionate and testosterone enanthate, instead of just testosterone. In such cases cyp and enth are esters (carboxylic acids) that have been attached to the 17-Beta hydroxyl group of the testosterone molecule which increase the active lifespan of the steroid preparation. Such alterations will reduce the steroid’s level of water solubility, and increase its oil solubility. Once an esterified compound has been injected, it will form a deposit in the muscle tissue (depot) from which it will slowly enter circulation. Generally the larger the ester chain, the more oil soluble the steroid compound will be, and the longer it will take for the full dosage to be released. Once free in circulation, enzymes will quickly remove the ester chain and the parent hormone will be free to exert its activity (while the ester is present the steroid in inert).
There are a wide number of esters used in medicine today, which can provide varying release times. To compare, and ester like decanoate can extend the release of active parent drug into the blood stream for three to four weeks, while it may only be a few of days with an acetate or propionate structure. The use of an ester obviously allows for a much less frequent injection schedule than if using a water based (straight) testosterone, which is clearly much more comfortable for the patient. We must remember when calculating dosages however, that the ester is figured into the steroids measured weight. 100mg of testosterone enanthate therefore contains much less base hormone than 100mg of a straight testosterone suspension (in this case it equals 72mg of testosterone). In some instances an ester may account for roughly 40% or more of the total steroid weight, but the typical measure is somewhere around 15% to 35%. Below are the free base equivalents for several popular steroid compounds.
100 Mg of steroid as: Approximate Free Equivalent:
Trenbolone acetate 87 mg
Testosterone prop 83 mg
Testosterone enth 72 mg
Testosterone cyp 70 mg
Testosterone undecanoate 63 mg
Nandrolone phenylpropionate 67 mg
Nandrolone deca 64 mg
It is also important to stress the fact that esters do not alter the activity of the parent steroid in any way, they work only to slow its release. It is quite common to hear people speak about the properties of different esters, almost as if they can magically alter a steroid’s effectiveness. This is really nonsense. Enanthate is not more powerful that cypionate (perhaps a few extra milligrams of testosterone released per injection, but nothing to note), nor is Sustanon some type of incredible testosterone blend. Personally I have always considered Sustanon a very poor buy in the face of cheaper 250mg enanthate ampules. Your muscle cells see only testosterone; ultimately there is no difference. Reports of varying levels of muscle gain, androgenic side effects, water retention etc. are only issues of timing. Faster releasing testosterone esters will produce estrogen buildup faster simply because there is more testosterone free in the blood from the start of the cycle. The same is true when we state the Durabolin is a milder nandrolone for women compared to Deca. It is simply easier to control the blood level with a faster acting drug. Were virilization symptoms to become apparent, hormone levels will drop much faster once we stop administering it. This should not be confused with the notion that the nandrolone in Durabolin Acts differently in the body than that released from a shot of Deca-Durabolin.
It is also worth nothing that while the ester is typically hydrolyzed in general circulation, some will be hydrolyzed at the injection site where the steroid depot first contacts blood. This will cause a slightly higher concentration of both free steroid and ester in the muscle where the drug had been administered. On the plus side this may equate to slightly better growth in this muscle, as more hormone is made available to nearby cells. Many bodybuilders have come to swear by the use of injecting directly into these muscles, truly believing better growth can be achieved if the steroid is injected directly. The negative to this is that the ester itself may be irritating to the tissues at the site of injection once it is broken free. In some instances it can be so caustic that the muscle itself will become swollen and sore due to the presence of the ester, and the user may even suffer a low-grade fever as the body fight off the irritant (the onset of such symptoms typically occurs 24-72 hours after injection). This effect is more common with small chain esters such as prop and acetate, and can actually make a popular steroid such as Sust. (Which contains testosterone propionate) off-limits for some users who experience too much discomfort to justify using the drug. Longer chain esters such as decanoate and cyp. are typically much less irritating at the site of injection, and therefore are preferred by sensitive individuals.
Ref Anabolics 2002/Teekahty fitnessgeared.com