For ease of use, testosterone is produced in the form of esters - this is when a carboxylic acid residue is attached to a testosterone molecule. This is necessary to create a depot drug that will be slowly released into the blood after injection. Otherwise, pure testosterone must be injected daily, as it is destroyed very quickly in the body.
How it works:
- Depot effect - when testosterone ester is dissolved in oil. When injected into the muscle, an oil depot is formed, from which testosterone is slowly released into the blood.
- Solubility - esters are highly soluble in oil, but poorly in water, which ensures slow release.
Key parameter - half-life (T1/2). The half-life is the time during which the concentration of testosterone ester in the blood will decrease by 50% after one injection. This indicator determines how often injections should be done to maintain a stable testosterone level.
The main factors affecting the half-life period:
The longer the ester chain, the better it dissolves in oil (higher lipophilicity) and the slower it enters the blood.
Examples:
- Testosterone propionate - T1/2 ≈ 1-2 days (short ester, requires frequent administration).
- Testosterone enanthate - T1/2 ≈ 5-7 days (medium ester, administered 1-2 times a week).
- Testosterone cypionate - T1/2 ≈ 8-10 days (medium ester, administered 1-2 times a week).
- Testosterone undecanoate - T1/2 ≈ 2-3 weeks (Much longer ester, than others, administered every few weeks).
Testosterone Propionate 100mg/ml 10ml (vial)
Practical significance:
Drugs with a short half-life require more frequent injections to maintain a stable hormone level. Long esters provide a more stable level of testosterone in the blood but take longer to «turn on» and «turn off».
Complete elimination of the drug from the body takes approximately two half-lives.
Important! The ester only affects the rate of testosterone release and the duration of the drug’s action. Testosterone itself, regardless of the ester, has the same effect on the body.
Key Testosterone Esters and Their Characteristics:
Let’s expand the description of testosterone esters, focusing on their features and practical application in bodybuilding. The AnabolShop.org team has compiled a detailed table of esters with their description, application, examples and features. For your attention, we present:
| Ester | Features | Application | Examples |
| Acetate (Half-life: ~1 day) | The shortest ester. Requires very frequent injections (often daily) to maintain a stable level of the drug in the blood. | Used mainly in preparations where a quick reaction and rapid elimination from the body are important (for example, before competitions). Often used in combination with other longer esters to create a «quick start» effect. | Trenbolone acetate (a powerful anabolic with a quick effect), testosterone acetate (rarely used solo due to a very short period of action but can be included in mixtures). |
| Propionate (Half-life: 1-2 days) | A short ester that requires injections every 1-2 days. Provides a relatively quick rise in testosterone levels in the blood and a faster elimination from the body compared to longer esters. | Suitable for cutting cycles, as it has less water retention compared to longer esters. Often used by women due to easier control of hormone levels and quick elimination in case of side effects. | Testosterone propionate (a classic drug for «short» cycles), drostanolone propionate (masteron, used to add definition). |
| Phenylpropionate (Half-life: 2-3 days) | Medium-length ester. Injections are usually done every 2-3 days. Provides a more stable hormone level in the blood compared to propionate. | Often used in testosterone mixtures where a balance is needed between a quick onset of action and a more stable hormone level. • Examples: Nandrolone phenylpropionate (a shorter ester of nandrolone than decanoate allows for a faster response to side effects), testosterone phenylpropionate (rarely used solo). | Testosterone Phenylpropionate is more suitable both for cutting and bulk. |
| Isocaproate (isohexanoate) (Half-life: 4-5 days) | Medium-length ester. Included in testosterone blends to ensure a smooth transition between the effects of different esters. | Used only in blends (Sustanon, Omnadren) to create a more complex pharmacokinetic profile. | This ether is not as popular as its analogues, and it is unlikely that a separate injectable testosterone with such an ether can be found anywhere, either in the US markets or in the markets of Europe and the CIS. |
| Enanthate (Half-life: 5-7 days) | A popular medium-length ester. Injections are made 1-2 times a week. Provides a relatively stable level of the hormone in the blood. | Widely used for gaining mass and strength. Suitable for long cycles. | Testosterone enanthate (the basic drug for testosterone cycles), trenbolone enanthate (less popular than acetate, but has a longer action), methenolone enanthate (primobolan, a softer anabolic with a long action). |
| Hexahydrobenzylcarbonate (cyclohexylmethylcarbonate) (Half-life: ~6-8 days) | An ester similar in properties to enanthate. Provides a relatively stable level of the hormone in the blood. | Almost exclusively used with trenbolone (parabolan). | Trenbolone hexahydrobenzylcarbonate (parabolan, is considered the «gold standard» among trenbolones due to the optimal combination of effectiveness and ease of use). |
| Cypionate (Half-life: up to 7 days) | Almost identical to enanthate in its properties. Often used in the USA. | Similar to enanthate - for gaining mass and strength. Suitable for long cycles. | Testosterone cypionate (a popular drug in the USA for testosterone courses), nandrolone cypionate (rarely used). |
| Decanoate (Half-life: 7-9 days) | Long ester. Injections are made once a week. | Used for smooth and long-lasting action. Often used in combination with faster esters to create a stable background. | Nandrolone decanoate (deca, one of the most popular anabolics for gaining mass), is part of Sustanon (to maintain long-term action). |
| Undecylenate (undecylenate) (Half-life: 9-11 days) | Long ester. Injections are made once every 1-2 weeks. | Used for long-term and smooth mass gain. | Boldenone Undecylenate (Equipoise, a softer anabolic with a long action). |
| Laurate (Half-life: 10-12 days) | The longest ester used in bodybuilding. Injections are done rarely (once every few weeks). | Provides a very long and smooth action. | Nandrolone Laurate (rarely used due to too long action and difficulties with hormone level control). |
Interesting fact! Did you know that the injection site can affect the rate of drug elimination? Injections into the deltoid muscle can slow down the elimination compared to injections into the gluteal muscles. Also, the effectiveness of the drug is affected by the type of solvent oil. Studies have shown that with the lengthening of the carbon chain in the solvent oil, the anabolic activity of the drug increases, and the androgenic activity decreases.1
Half-Life and Half-Absorption of Esters: Understanding the Athlete
Drug half-life graph
When it comes to using testosterone esters and other anabolic steroids in bodybuilding, it is important to understand how long the drug will be active in the body. This is where two key concepts come into play: half-life and half-absorption, which are often confused.
What is half-life (T1/2)?
Imagine you injected testosterone enanthate. The half-life tells you how long it will take for the level of this testosterone in your blood to decrease by half. This is important for the following reasons:
- Calculating injection frequency. Knowing the half-life, you can determine how often you need to inject to maintain stable levels of the drug in the blood. For testosterone enanthate with a half-life of 5-7 days, it is usually recommended to inject 1-2 times per week.
- Determining the duration of the cycle. Knowing that the drug will be active for several half-lives allows you to plan the duration of the cycle.
- Planning post-cycle therapy (PCT). It is important to understand when the drug will be completely eliminated from the body to begin PCT and restore natural testosterone production.
What is the half-life (T1/2,a)?
This indicator shows how long it takes for half of the drug from the injection site to be absorbed into the blood. With testosterone esters, this process occurs gradually, so the half-life is important for understanding when the drug will begin to act at full strength.
What is the difference and how to apply it in practice?
It is important to understand that the half-life characterizes the concentration of the drug in the blood, and the half-life characterizes the rate at which the drug enters the blood from the injection site. Consider these factors when planning a cycle to achieve optimal results.
- Short-acting esters (e.g. testosterone propionate) are rapidly absorbed and rapidly eliminated, providing a quick effect, but require frequent injections.
- Long-acting esters (e.g. testosterone enanthate) are slowly absorbed and slowly eliminated, providing a more stable level of the hormone in the blood, but require more time to achieve maximum effect.
Example:
The graph shows how plasma estradiol levels change after a single dose of Aromasin (25 mg exemestane) in 10 young men.
Immediately after administration, there is a sharp decrease in estradiol levels by approximately 60-70%, which confirms the high effectiveness of the drug in suppressing this hormone. The concentration then gradually returns to the original level over approximately 7-10 days.
This clearly demonstrates how quickly and reliably Aromasin reduces estradiol, which is important for controlling hormonal balance in certain therapeutic tasks.
After an injection of 100 mg of nandrolone decanoate:
- After 7 days, the concentration of the drug in the blood will drop by half.
- After 14-15 days, 50% of the administered drug will be destroyed.
- The drug’s action formally ends after 4 half-lives (when approximately 5% of the concentration remains).
By the way, on the Internet you can often find graphs of the half-absorption period, which must be divided by 2 to get the half-life, which characterizes the concentration of the anabolic in the blood.2 3
| How much muscle can you gain and burn fat on testosterone? | |||||
| Testosterone Amount | 100 mg/every other day | 50 mg | 125 mg | 300 mg | 600 mg |
| Lean Muscle Mass (kg, ± difference) | -1.0 ± 0.5 | +0.6 ± 0.4 | +3.4 ± 0.8 | +5.2 ± 0.8 | +7.9 ± 0.6 |
| Fat Mass (kg, ± difference) | +3.6 ± 1.5 | +2.6 ± 1.0 | -0.3 ± 0.8 | -0.9 ± 0.6 | -2.0 ± 0.7 |
| Testosterone Level, ng/mL | 253 ± 66 | 306 ± 58 | 570 ± 75 | 1,345 ± 139 | 2,370 ± 150 |
What is the best testosterone ester?
We will answer right away that the AnabolShop.org team considers Testosterone Cypionate to be the best. It is a popular choice for testosterone injections. At a dosage of 200-250 mg, injections every 2-3 weeks are a good option, but it is worth remembering that testosterone levels will fluctuate.
Pros of Testosterone Cypionate (if we consider only the effect of use):
- Testosterone Cypionate is one of the most effective anabolic steroids for building muscle mass. The effect can be more noticeable compared to other «softer» steroids.
- Increased strength. Along with the growth of muscle mass, there is a significant increase in strength. This allows you to lift heavier weights, which in turn contributes to even greater muscle growth.
- Testosterone promotes faster muscle recovery after training, which allows you to train more often and more intensely.
- Increased protein synthesis. Testosterone stimulates protein synthesis in muscles, which is a key factor in the growth and recovery of muscle tissue.
- Testosterone plays an important role in maintaining bone density and increasing it can help strengthen bone tissue.
- Improved Mood and Confidence (in Some Cases): Increased testosterone levels can, in some cases, lead to improved mood, increased self-confidence, and motivation. (But it can also lead to aggression and irritability.)
Fun fact for those with red blood cell issues! Testosterone can stimulate red blood cell production, which can improve endurance and aerobic performance.
Course with Testosterone Cypionate
Typical course of testosterone cypionate and ways to minimize side effects.
- Injections - 1 time per week to maintain stable testosterone levels.
- Dosage - 250-500 mg per week for mass gain. Doses above 800-1000 mg increase the risk of side effects without significantly improving results.
- Estrogen blocking:
- Tamoxifen - 10 mg per day, starting from the second week of the course and continuing for 2 weeks after its completion.
- Proviron (preferred) - during the course, then replaced with Tamoxifen after the end of the testosterone course to restore your own testosterone production.
- Gonadotropin - if the course is longer than 4 weeks, 500 IU 1 time per week, starting from the 3rd week of the course, to prevent testicular atrophy.
The use of antiestrogens reduces water retention and prevents gynecomastia. It is recommended that you study information about PCT (Post Cycle Therapy).
And in conclusion, in the article, we will tell you that the choice of which ether to use is entirely yours! In short - long ether is preferable for mass, short - for drying.
This article provides relevant and detailed information.
Regarding the purchase of the drug, it is available on our official website AnabolShop.org. Order all the drugs you are interested in directly from us!
For each drug, there is a detailed description of the effects, course, side effects and price with information on delivery. Thank you for reading. The drugs you are interested in are in the corresponding category in the store catalog. Starting from oral drugs, ending with injectable steroids, Growth Hormone and PCT drugs.
Good anabolism to all!
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- http://thinksteroids.com/articles/anabolic-steroid-esters/
- http://jcem.endojournals.org/content/90/5/2624.full
- http://www.roidcalc.com/