"Testosterone is available in a variety of preparations, esterified variants, and forms.
Each formulation is described and covered here."
Major Testosterone Esters
With the exception of a few products, almost all injectable anabolic steroids undergo a process called esterification.
Esterification is a chemical reaction in which carboxylic acids of varying lengths are chemically bonded to an anabolic steroid at the 17-beta hydroxyl group.
This is called esterification (or ester bonding), and the ester serves to extend the rate of release and half-life of the hormone in the body.
This occurs as enzymes break down the ester attached to the anabolic steroid.
This happens primarily in the liver, but also occurs in the bloodstream.
The body must first break down the ester through the aforementioned enzymes before the anabolic steroid hormone is free to act in the body.
By this time, the anabolic steroid has left the injection site and is circulating systemically in the body.
As a result, all anabolic steroids work systemically, based on the body's needs, rather than locally and site-specifically.
Testosterone suspension, for example, is a form of unesterified testosterone, as it is pure testosterone suspended as crystals in water.
Pure, unesterified testosterone has a very short half-life, which is not only too short for practical use, but also inconvenient to take.
Therefore, different types of ester bonds have been formed to create different esterified testosterone variants with the aim of making it easier to administer and extending the half-life to a more practical and usable length.
Adding ester bonds to the testosterone molecule maximizes its use in both medical and non-medical applications.
While an almost infinite number of esterified forms and variants of testosterone can be created or discovered, there are three main popular types that are well known in the medical community and anabolic steroid use community.
These are (in order of popularity):
1. testosterone enanthate
2.Testosterone cypionate
3. testosterone propionate
In addition to these esterified variants, there also exist what are known as blends of testosterone, which are preparations and products that are a mixture of the above-mentioned esterified forms of testosterone.
For example, one of the most well-known blends is Sustanon 250, which contains a total of 250 mg of testosterone divided into the following blended amounts
30 mg of testosterone propionate, 60 mg of testosterone phenylpropionate, 60 mg of testosterone isocaproate, and 100 mg of testosterone decanoate for a total of 250 mg of testosterone esters (hence the number 250 in the name Sustanon 250).
There are also other blended type products that contain different amounts of different testosterone ester types, such as a 450mg blend of several different testosterone ester types.
There are other less popular esterified forms of testosterone, such as testosterone acetate, and there are other testosterones included in the Sustanon 250 blend (testosterone decanoate, phenylpropionate, isocaproate, etc.), but for the purposes of this article, we'll focus on the three main types listed above and discuss them in detail.
Testosterone Enanthate
Testosterone enanthate is probably the most popular and most widely used esterified variant of testosterone.
This is mostly due to its longer half-life and longer release period, which makes it more convenient for injection dosing protocols.
Testosterone enanthate has a half-life of approximately 7 to 10 days, making it conveniently injectable once or twice a week, unlike testosterone propionate, which must be injected every other day.
Unesterified testosterone, such as testosterone suspension, requires more frequent injections, at least once a day, which is even worse for those who are afraid of needles or don't want to inject frequently.
Its long half-life makes it more suitable for medical and TRT use, but as mentioned earlier, it is also suitable for performance enhancement use if you don't want frequent injections.
2.Testosterone Cypionate
Testosterone cypionate is chemically different from testosterone enanthate, but is considered to be nearly equivalent.
Testosterone cypionate has a similar half-life, although it is slightly longer (about 12 days for testosterone cypionate and about 10 days for testosterone enanthate).
Another major difference between the two is the country of origin, with testosterone enanthate being an international product produced primarily overseas, while testosterone cypionate is traditionally an American product.
Both products have very similar half-lives and are almost equally popular among anabolic steroid users, with testosterone enanthate being more popular.
In fact, the two esterified testosterone variants are so similar to each other that they are easily interchangeable within a cycle (for example, someone on a 10-week testosterone cycle can use testosterone enanthate for the first five weeks and switch to testosterone cypionate for the remaining five weeks without any problems).
The convenience of testosterone cypionate is the same as other long acting compounds such as testosterone enanthate, with the ease and convenience of more frequent dosing.
3 Testosterone Propionate
Testosterone propionate is the third most popular of the three main types of testosterone esters, despite being the first esterified form of testosterone.
The propionate ester prolongs the half-life of testosterone in the body to about 4.5 days, which is much shorter than the two esterified testosterones discussed earlier.
As such, it requires a much more frequent injection and dosing protocol (at least every other day injections) than the other ester types to maintain stable plasma concentrations of the hormone, making it less popular with the majority of individuals who prefer less frequent injections.
Nevertheless, this is not to say that Testosterone Propionate is an unpopular anabolic steroid.
On the contrary, it is very popular and caters to a preferred niche group among other anabolic steroid users.
It's just that due to its inconvenient and inconvenient injection and administration schedule, Testosterone Propionate is the least popular of the three.
Achieving stable plasma levels with three esterified testosterone variants
It is very important to understand the importance of maintaining stable plasma levels of a hormone to ensure adequate optimal gains, optimal physiological functioning, and reduced incidence of side effects.
Many anabolic steroids are esterified, which increases the release and half-life of the hormone, but esterification does not guarantee a completely stable peak blood concentration.
Even long esterified variants of testosterone such as testosterone enanthate, testosterone cypionate, testosterone decanoate, etc. have a very rapid release of the hormone from the injection site after administration, and the enzymatic elimination of the ester results in a fairly rapid rise in plasma concentrations of testosterone given the total half-life of the long ester [1].
Maintaining adequate and stable peak blood levels of testosterone is essential for the hormone to function properly, so understanding this is very important when it comes to proper dosing and dosing schedules.
Blood levels of almost all ester types peak approximately 48 hours after injection.
This also means that despite the misinformation being circulated that esterified testosterone variants 'take longer to work', these compounds actually work very quickly after injection administration.
The difference between these esters is the time required to reach optimal plasma blood levels, which is typically reached over a longer period of time for longer esters such as cypionate and enanthate.
The "lifespan" of an esterified hormone (in this case testosterone) is increased by the ester due to the time required for enzymes to liberate the hormone from the bound ester.
Part of the rate of release of esterified anabolic steroids is also related to their solubility in fat, although this does not affect the half-life as much as the enzymatic breakdown of the ester itself.
Esters are lipophilic (fat soluble) because they are long chain hydrocarbons, which are mostly classified as fats, and therefore the compounds they chemically bind to are also lipophilic (in this case, testosterone). Since testosterone and all anabolic steroids are already in the form of lipids (fats), adding an ester increases the hormone's solubility in oils and fats.
After injection, the oil containing the hormone forms a depot (precipitate) within the muscle tissue, and the hormone gradually separates from the oil, which is lipophilic, and circulates in the bloodstream.
Therefore, it stands to reason that the longer the hydrocarbon chain of the corresponding ester, the more fat-soluble the hormone, and therefore the longer it will be released.
This is why anabolic steroids with very long ester chains, such as Deca Durabolin (Nandrolone Decanoate), have a long half-life and are known to remain in the body's adipose tissue for months after administration is stopped.
Once the hormone is released from the injection site into the bloodstream circulation, enzymes work to break down the ester from the hormone, as we have already mentioned several times.
It is very important to note that while the hormone is bound to the ester, the anabolic steroid hormone is inactive and cannot do anything until the ester is removed.
Given the half-life of the different types of testosterone esters, there are different protocols to consider in order to achieve stable plasma levels.
There is also a difference between someone who wants to use testosterone for the purpose of athletic performance and physique enhancement versus someone who wants to use it for the purpose of TRT.
It should first be explained that the use of any ester type of testosterone for TRT allows for a much more lenient and looser injection protocol than for performance enhancement purposes.
This is because the overall goal of TRT is to maintain normal physiologic testosterone levels and proper normal physiologic function.
Therefore, individuals using the following testosterone variants for TRT should ensure that they are operating efficiently and in accordance with appropriate injection frequency protocols as outlined in their medical prescribing guidelines:
Testosterone Enanthate (TRT): Administered (injected) once every 2-4 weeks.
Testosterone cypionate (TRT): Once every 2-4 weeks (injection).
Testosterone propionate (TRT): Administered (injected) 2-3 times per week (average of Monday/Friday or Monday/Wednesday/Friday injection protocols).
Sustanon 250 or any testosterone blend (TRT): Once every 3 weeks (injection).
The injection protocol and frequency for the purpose of TRT is not set in stone and can be adjusted at any time based on patient and physician discussion and decision.
For example, many doctors will often work with their patients to establish a weekly injection cycle of testosterone enanthate or cypionate.
Many medical professionals believe that the injection protocols outlined in the medical prescribing guidelines need to be revised to allow for more frequent injections to achieve more stable blood levels, but nevertheless, the medical prescribing guidelines remain as listed above.
However, the general idea here is to emphasize the fact that the frequency of injections can always be adjusted according to individual needs, especially after monitoring with blood tests.
The dosing protocols for different types of testosterone esters for athletic performance and physique enhancement are very different and require much more frequent injection protocols and schedules.
This is due to the need to specifically increase changes in strength, size, and body composition while minimizing the occurrence of side effects, and this can only be achieved by properly reaching peak plasma concentrations:
Testosterone enanthate (performance enhancement): Administered twice weekly (injections), each injection evenly spaced (e.g., Monday and Thursday injections).
Testosterone cypionate (performance enhancement): Twice weekly dosing (injections), each injection equally spaced (injections) (e.g., Monday and Thursday injections).
Testosterone propionate (athletic performance enhancement): 1 dose (injection) every other day.
Sustanon 250 or any testosterone blend (athletic performance enhancement): One dose (injection) every 7 to 10 days, some protocols may require a dose every 3 days.
Ester forms of testosterone, such as testosterone cypionate or enanthate, have a longer half-life of about 10 to 12 days, but at least weekly dosing is essential for physique and athletic performance gains, and the best approach is to dose evenly spaced twice weekly.
While it is possible to 'wing it' with weekly injections, this is not recommended as unstable blood levels are associated with a higher incidence of side effects and less likely to have the desired effect on athletic performance.
Blended products like Sustanon 250 are a complex and interesting topic. This is because the disadvantages of Sustanon 250 to athletes and bodybuilders compared to other single testosterone ester types have already been defined many times over.
These disadvantages are mostly due to the fact that there is little control over the different release rates of the various testosterone esters within a Sustanon 250 mixture.
As such, users looking to use Sustanon 250 (or any type of mixed testosterone product) will find that they have much less control and management over the half-life and proper dosage.
Nevertheless, in order to improve physique and athletic performance, Sustanon 250 should be administered approximately every 7 to 10 days instead of the medical guidelines of once every 3 weeks.
Some people even prefer to administer Sustanon 250 every three days because of the use of a short ester testosterone variant in the mixture.
If a product is a blend (whether it's Sustanon 250 or another underground lab-type custom blend), you should always base your dosing protocol on one ester type within the blend:
The two ester types that are composed of the largest amounts of all other ester types within the product.
The shortest ester type (if it is composed of the highest concentration of all other ester types within the blend).
Pharmaceutical Grade vs. Underground Testosterone
Testosterone is a very popular and extremely common anabolic steroid, both in pharmaceuticals and on the black market around the world.
Most individuals who use testosterone for physique and performance enhancement purposes typically purchase their anabolic steroids through the black market, which can include pharmaceutical grade products as well as under-the-lab (UGL) products.
However, the majority of testosterone (or any anabolic steroid) products on the black market are actually UGL quality.
Pharmaceutical grade products are also available on the black market, but the risk of counterfeit products is very high.
This is unfortunately due to the legal environment surrounding anabolic steroids, which has created a global environment where only about 20% of the black market for anabolic steroids is pharmaceutical grade and 80% of the market is saturated with illegal non-pharmaceutical (UGL grade) and counterfeit products.
While the majority of UGL products are used by those seeking to use them for athletic performance enhancement purposes, there are also those who wish to self-manage their TRT by purchasing UGL grade testosterone instead of going through a doctor and purchasing testosterone products through a pharmacy.
Regardless of the purpose of use, there are two types of testosterone products that every individual will encounter when purchasing testosterone products
1. pharmaceutical grade
2. under laboratory (UGL) grade
Pharmaceutical Grade
These are medicines designed and promoted by pharmaceutical companies approved by the FDA (or equivalent association).
The products produced by these companies are of very high quality, precise dosage, and undisputed sterility and purity.
This is due to the strict quality controls imposed by the FDA (or similar international organization).
Of course, the downside of these high-quality products is that they are expensive due to the high cost of manufacturing and R&D.
Under Laboratory (UGL) Classification
Underground laboratories are laboratories established (illegally, depending on the country) to produce anabolic steroids.
These labs are not inspected, supervised, or approved by the FDA (or equivalent).
The manufacturing conditions under which these labs operate can range from pharmaceutical-grade facilities to home-based labs set up in people's homes, which can translate into a wide range of product quality (due to the lack of FDA or similar oversight and quality control).
The advantage of UGL grade products is, of course, the lower cost of the product compared to pharmaceutical grade anabolic steroids.
Testosterone Creams, Patches, and Gels for TRT
The last testosterone variants and products we will discuss are testosterone creams and gels for TRT purposes.
Transdermal patches, gels, and creams are products that utilize a transdermal method of administration as opposed to an oral or injectable route of administration.
Transdermal administration is a route of administration in which the active ingredient in a cream, gel, or patch passes through the skin through the pores and into the bloodstream, where it circulates.
While there are some advantages to transdermal administration, there are also a number of disadvantages.
Because TRT is a treatment method that requires the continuous administration of testosterone on a daily or weekly basis (depending on the route of administration), this method can be convenient for individuals who do not want to inject for any reason.
However, transdermal administration of testosterone tends to have far more potential disadvantages than advantages.
Pros of transdermal administration: The main advantage is convenience, as you only need to rub a certain amount of gel or cream topically or apply a patch each day.
Disadvantages of transdermal administration: There are a number of concerns and disadvantages associated with transdermal administration of creams and gels.
The first concern is the issue of skin-to-skin contact with the person using the topical gel or cream, which can result in the transfer of testosterone from the TRT patient to another person.
This can cause problems with contact with the TRT patient's wife or girlfriend, or close contact involving children and babies.
Risks that may arise from this transfer include unexpected signs of pubertal development in children and masculinization in women who have had physical contact with patients using TRT gels/creams.
Skin-to-skin contact is not the only way that transfer can occur, as the substance can also remain on unwashed clothing, bed sheets, pillows, etc. if they come into contact with areas of the body where the topical gel or cream has been rubbed.
While most testosterone gels are designed to be quickly absorbed into the skin and dry fairly quickly where applied, there is still an inherent risk of transfer.
Another concern associated with transdermal administration is the increased rate of testosterone conversion to estrogen.
Clinical studies have shown that a higher percentage of body fat is associated with a higher risk of estrogenic side effects [2].
This is because the aromatase enzyme is very abundant in adipose tissue (fat), so it makes sense that the higher an individual's body fat percentage, the higher the rate of aromatization of androgens into estrogen.
When testosterone is applied topically and absorbed into the skin (through the skin), it must pass through subcutaneous adipose tissue, which can increase the rate of aromatization.
Testosterone gels and creams have been proven to be just as effective as other forms of testosterone administration in several studies [3].
In these studies, transdermal testosterone effectively increased sexual function, mood, lean body mass, and bone density in patients with hypogonadism.
It is important to note that transdermal testosterone application, like other methods of testosterone administration, has the potential for side effects and risks.
The two main brands and forms of transdermal testosterone available are AndroGel (sold as 1% or a higher concentration of 1.62%) and Testim 1%.
AndroGel is the most widely used and most popular topically applied testosterone gel product for TRT applications.
AndroGel is manufactured by Besins Iscovesco in Paris, France and marketed and distributed by Solvay Pharmaceuticals.
AndroGel is composed of 1% testosterone, which is equivalent to 10 mg per gram of gel, and studies have shown that topical application of 10 grams of gel to the skin has the same effect as 100 mg of testosterone administered into the body [4] [5].
Initially, there were no generic brands of testosterone gel, but in recent years, generic products developed by compounding pharmacies have been reported to cost less than half the price of brand name AndroGel.
Although it is reportedly difficult to obtain and rare, it is gaining popularity.
Medical references:
[1] Testosterone Action Deficiency Replacement 2nd ed. E. Nieschlag HM Behre (Eds.) Springer-Verlag Berlin Heidelberg New York (1998)
[2] Aromatization of androstenedione and 19-nortestosterone in human placenta, liver and adipose tissue (abstract). Nippon Naibunpi Gakkai Zasshi 62 (1986:18-25)
[3] Long-term testosterone gel (AndroGel) treatment maintains beneficial effects on sexual function, mood, lean and fat mass, and bone density in hypogonadal men. Christina Wang, Glenn Cunningham, Adrian Dobs, Ali Iranmanesh, Alvin M. Matsumoto, Peter J. Snyder, Thomas Weber, Nancy Berman, Laura Hull, and Ronald S. Swerdloff. Wang et al. 89(5):2085
[4] Gel Study Group 2000 Comparative pharmacokinetics of two doses of transdermal testosterone gel and testosterone patch after daily application for 180 days in hypogonadal men. Swerdloff RS, Wang C, Cunningham G, Dobs A, Iranmanesh A, Matsumoto A, Snyder P, Weber T, Berman N and TJ Clin Endocrinol Metab 85:4500-4510
[5] Pharmacokinetics of transdermal testosterone gel in hypogonadal men: application of gel to one site versus four sites. Wang C, Berman N, Longstreth JA, Choapoco B, Hull L, Steiner B, Faulkner S, Dudley RE, Swerdloff RS 2000 J Clin Endocrinol Metab 85:964-969
