The following article was written by Dan C from Steroidal
It is important for every person to understand that the ester which is attached to any injectable anabolic steroid possesses a certain percentage amount of the total molecular weight of the molecule. Therefore, for example, 100mg of Testosterone Enanthate is not 100mg of pure Testosterone. The reality is that you are receiving less Testosterone than most of you think, and once the ester has been removed through the esterase enzyme, the amount of pure un-esterified Testosterone left over is very different depending on the ester in question that was previously attached to the hormone.
Long chain esters, such as Cypionate, Decanoate, Enanthate, etc. possess a much weightier molecular weight than short chain esters. Consequently, on a mg for mg basis, you are receiving far extra mg of steroid in a short estered compound as opposed to a large estered compound. As an example, there exists a larger amount of mg of Testosterone in 100mg of Testosterone Propionate than 100mg of Testosterone Enanthate. This is due to the shorter, and therefore lighter weight of the Propionate ester in comparison to the larger and therefore much heavier Enanthate ester. Many individuals just do not realize this, and should always consider this factor as one of the factors involved in the decision making process concerning which ester variant of any given compound to use during a cycle.
Without complex mathematical explanation as to how much of the ester weight is determined to occupy in a given compound, here is a list of some of the most common esterified injectable compounds and how much free hormone is left in a given amount of the compound (standardized to 100mg).
- 100mg Testosterone Suspension (un-esterified Testosterone) = 100mg Testosterone
- 100mg Testosterone Acetate = 83mg Testosterone
- 100mg Testosterone Propionate = 80mg Testosterone
- 100mg Testosterone Isocaproate = 72mg Testosterone
- 100mg Testosterone Enanthate = 70mg Testosterone
- 100mg Testosterone Cypionate = 69mg Testosterone
- 100mg Testosterone Phenylpropionate = 66mg Testosterone
- 100mg Testosterone Decanoate = 62mg Testosterone
- 100mg Testosterone Undecanoate = 61mg Testosterone
- 100mg Trenbolone Acetate = 87mg Trenbolone
- 100mg Trenbolone Enanthate = 70mg Trenbolone
- 100mg Trenbolone Hexahydrobenzylcarbonate = 70mg Trenbolone
- 100mg Nandrolone Phenylpropionate = 67mg Nandrolone
- 100mg Nandrolone Decanoate = 64mg Nandrolone
- 100mg Drostanolone Propionate = 80mg Drostanolone
- 100mg Drostanolone Enanthate = 70mg Drostanolone
If one wishes to find out the specific weight of a specific amount of esterified hormone, the steps are simple. Let us take Primobolan (Methenolone Enanthate) as an example. We want to figure out how much free Methenolone exists in 750mg of Methenolone Enanthate (Primobolan).
First we must find out the molecular weight of Methenolone itself (UN-ESTERIFIED – this is very important): 302.451 g/mol
We then must find out the molecular weight of the Enanthate ester (when unattached to any molecules, it is properly referred to as heptanoic or enanthic acid): 130.18 g/mol
The two weights must then be added in order to determine the total weight of Methenolone Enanthate: 302.451 + 130.18 = 432.631 g/mol
The total weight must then be divided by the weight of the ester in order to find out how much percentage of the total weight is occupied by the Enanthate ester: 432.631 / 130.18 = 3.3233292364419
This number is our percentage, but it must be multiplied by 10 to obtain the proper figure. We end up with 33% (rounded off).
33% of the Methenolone Enanthate molecule is occupied by the Enanthate ester. We wanted to know how much pure and free Methenolone is left over in 750mg of Primobolan. This is a two-step process, so we must then first subtract 33% from 750mg: 750 x 0.33 = 247.5mg
247.5mg is how much weight the Enanthate ester comprises the 750mg total of Primobolan. If we subtract that number from 750, we get: 502.5mg of un-esterified free Methenolone left over from 750mg of Methenolone Enanthate (Primobolan).