What is the half-life of steroids?

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This is crucial to understand the concept of a half-life of steroids, not only for anabolic steroid use alone, but for the use of any drugs, substances, and even foods that you consume. The concept of a steroid half-life is a concept within science that applies to almost all disciplines of science: physics, biology, chemistry, and more. Although, depending on the area of scientific study, there can be different definitions of what a half-life is the general definition is the same.

For example, the dictionary definition of half-life in physics is Physics. The time required for one half the atoms of a given amount of a radioactive substance to disintegrate. While the dictionary definition of half-life as it pertains to biology is: Also called biological half-life. Pharmacology. The time required for the activity of a substance taken into the body to lose one half its initial effectiveness. The general or informal dictionary definition of half-life is Informal. A brief period during which something flourishes before dying out.

Different dictionary definitions can be different, but the general concept of a half-life as it pertains to biology and pharmacology is: the amount of time it takes for a substance, drug, or food to be reduced to one of half of its original administered dose, in a process that happens repeatedly until the drug is in the body. Let’s consider that an individual injects 100mg of Testosterone Propionate, which exhibits a half-life of 4.5 days, meaning that in 4.5 days, only 50mg of the substance will be remaining in his or her body. The concept of the half-life of steroids is extremely important to understand, as it allows the individual to understand the total amount of time a particular anabolic steroid or drug remains active in the body after administration. This knowledge and understanding will assist and help the individual to better plan and organize his or her cycle appropriately, and understand how to properly time the administration of the anabolic steroids to achieve the most effective, comfortable, and safe cycle. Also, the proper understanding of steroids half-lives is very important for the understanding of how long it might take before a particular compound reaches peak optimal blood plasma levels in the body. This is very significant to know, as the results and gains experienced from anabolic steroids do not normally occur until these peak optimal blood plasma levels are achieved in the body. The longer is steroid half-lives, the longer time it will take for the gains to ‘kick-in’ on the cycle. Let’s not forget about safety, all information about particular steroid should be obtained, to ensure safe use. Without a proper understanding of the half-live of a drug, there is the possibility that an individual will improperly administer the drug, which in turn, can result in self-injury, harm, or even death. Unfortunately, in a lot of cases then the improper administration timing according to the half-lives of different steroids used can result in a very dangerous and unpleasant experience, which will most often increase the severity and appearance of the side effects. The understanding of steroid half-lives is one of the main concepts that should be investigated before the use of any anabolic steroids.

What Factors Affects the Different Steroid Half-Lives?

Different anabolic steroids have different half-lives because they are affected by a few different factors, the three primaries of which are: the route of administration, esterification, and resistance to metabolism. How steroid is administered – that factor plays a very significant role in the half-life of an anabolic steroid. There are two primary routes of administration for anabolic steroids: oral and injectable. A third route would be transdermal patches, gels, or creams, which are methods of absorption through the skin. Anyway, the use of anabolic steroids for physique and performance enhancement almost always is achieved through either oral administration or injection. There are also other less popular methods of administration existing, such as implantation pellets and sublingual and nasal applications, though they are far too rarely used.

Pills and tablets have the shortest steroid half-lives among the different compounds, meaning they lose their potency very quickly and break down the fastest in your system. This happens because the vast majority of anabolic steroids are un-esterified, and are ingested in their pure and immediately active format. As the oral route of administration presents no delay in the release of the anabolic steroid to the bloodstream, the hormones are instantaneously active and playing an active role in the body as soon as they hit the bloodstream (after they make the first pass through the liver). Although these oral anabolic steroids undergo a first pass through the liver, the amount of metabolism through the hepatic (liver) pathway does not slow down the release of the hormones into the bloodstream by much. One of the main reasons why oral steroid half-lives are much shorter comparing to injectable steroid half-lives is because of the immediate exposure to liver metabolism, which facilitates faster metabolism and elimination of the hormone in and out of the body. In general, oral anabolic steroid half-lives range from 4 hours to 48 hours, depending on the anabolic steroid used.

Injections have some of the longest half-lives mostly its half-lives are significantly longer than oral anabolic steroid half-lives. Injectable anabolic steroids consist of two different types: oil-based injectable, which forms a depot in the muscle tissue they are injected in and slowly released from the injection site into the bloodstream, and the water-based injectable, known as suspensions, where the hormone is suspended in microcrystals that are in a water base. Once water-based suspensions are injected into muscle tissue, the microcrystals are slowly dispersed and released into the bloodstream into circulation. The nature of oil-based and water-based injections, which are designed to form a depot in the muscle tissue they are injected in, after which a slow release from the injection site into the bloodstream occurs in the hours or days after the injection. This factor significantly extends the steroid half-lives, but it is an additional factor that extends the injectable steroid half-lives even more: esterification. Almost all anabolic steroids, especially oil-based, are esterified to deliberately extend their half-life and to make them more fat-soluble to better dissolve in the carrier oil. The only exception is Testosterone Suspension and Winstrol (Stanozolol), both of which are injectable anabolic steroids that are not esterified at all.

In general, injectable anabolic steroid half-lives range from 24 hours to as long as 15 days or more, depending on the anabolic steroid used and whether or not it is esterified (and what kind of ester is bound to it). Esterification is maybe the most influential contribution to the different steroid half-lives. Esterification is a process whereby a carboxylic acid is bound to an anabolic steroid’s 17-beta hydroxyl group. This type of bonding is known as esterification (also known as an ester bond). The carboxylic acids that are esterified to an anabolic steroid are of different and varying lengths, normally in the form of a carbon chain. The longer the carbon chain of the carboxylic acid, the longer it is, and therefore the longer the anabolic steroid’s half-life will be extended.

Immediately after the anabolic steroid is injected into the body, it is slowly starting to release from the injection site into the bloodstream, and once in the bloodstream, the body’s esterase enzymes will break off the ester from the anabolic steroid. Longer ester bonds will require more time for these enzymes to free the hormone from the ester. That the process ended and the anabolic steroid hormone is broken free from the ester, what remains is a pure and active anabolic steroid that is free to do its work in the body. For example, pure and un-esterified Testosterone expresses a half-life of approximately 4 – 24 hours, while the TESTOMED P 100 (Testosterone Propionate)  expresses a half-life of 4.5 days, and TESTOMED E 250 (Testosterone Enanthate)  expresses an even longer half-life of 7 – 10 days in the body.

Esterification was deliberately devised by scientists back in the 1930s with purpose to deliberately extend the half-life of different anabolic steroids. Most anabolic steroids when un-esterified will express an extremely short half-life, making them very impractical for medical or clinical use because too frequent injections will be necessary. That is a very uncomfortable experience for most of the people. Esterification successfully extends the half-life of anabolic steroids to lengths that would require not so frequent injections and therefore allows applying more comfortable injection schedules.

That is also worth to mention the amount of resistance to the body's metabolism, which also affects the half-life of a given anabolic steroid. Although that is not as influential as the aforementioned three factors, it also affects the steroid half-lives. For example, some oral anabolic steroids exhibit a half-life of 4 hours, while others will exhibit a half-life of 24 hours. This is so because some anabolic steroids are much more resistant to metabolism in the liver (and/or elsewhere in the body), and therefore are not broken down as easily or as quickly. Anyway, all drugs, anabolic steroids, foods, chemicals, and compounds eventually undergo metabolism and elimination from the body – there is no such anabolic steroid or drug that will last forever in its active state in the body.

What Steroid Half-Lives Do and How to Properly Structure Cycles According to Them

As we already know, there are different anabolic steroid half-lives for the different anabolic steroids, and not every anabolic steroid can be administered in the same manner or the same frequency. For example, DIANAMED 10 (Methandienone), exhibits a half-life of approximately 4 – 6 hours, which might require multiple daily administrations to maintain stable blood levels of the hormone. That is also the same for WINIMED 10 (Stanozolol), which expresses a half-life of 9 hours in the body, and therefore individuals could easily get by with ingesting their full dose all at once.

It is important to realize that for performance and physique enhancement, frequent administration of anabolic steroid is very necessary to maintain stable and optimal blood plasma levels. For medical use, the administration of an anabolic steroid on the last day of its half-life might be acceptable, but for performance and physique enhancement, that is a different situation as the administration and dosage protocol changes dramatically. As the desired result now is to increase performance and/or muscle mass and strength, the higher than normal (therapeutic) physiological bodybuilding doses are required, as well as a higher frequency of injections,  are required to maintain optimal peak blood plasma levels of the hormone. For example, there is no need for a TRT (Testosterone Replacement Therapy) to be concerned about performance increases from week to week (or even day to day), but athletes and bodybuilders must. While the human body manufactures an endogenous Testosterone level in the range of 70mg/week, the Testosterone dosage required for physique and performance enhancement must be well above that level, with a minimum being in the range of 300 – 500mg per week for beginners, for example. Intermediate and/or experienced anabolic steroid users can venture even higher than that. In addition to the higher bodybuilding dosage, the injections also must be administered much more frequently.

While for TRT patients the single 250mg injection of  TESTOMED E 250 (Testosterone Enanthate) once per week (or even once every two weeks as is commonly applied clinically) can be enough, an athlete or bodybuilder would have to administer 250mg of  TESTOMED E 250 (Testosterone Enanthate) twice per week (for a total of 500mg) in order to experience a steady onset of performance and physique enhancing benefits. This is necessary due to a constant steady peak blood plasma level of the anabolic steroid that is necessary for constant biological action within muscle tissue in the body. TESTOMED E 250 (Testosterone Enanthate) exhibits a half-life of 7 – 10 days, but although its half-life is 7 – 10 days, sharp declines in blood plasma levels begin to occur several days before the end of the half-life period. When the main goal is the performance and physique enhancement, the administration of doses must occur more frequently to keep blood plasma levels elevated as best as possible. For medical purposes such as TRT, sharp spikes and peaks and valleys in blood plasma levels can be afforded (although it is still not optimal), because the patient is simply utilizing Testosterone to obtain normal physiological levels, and is therefore not particularly concerned with dramatic performance or physique changes weekly.

The dosages of anabolic steroids administered on a daily or weekly basis should be split evenly per administration. If the user is planning to administer 500mg per week of Testosterone Enanthate as two injections per week, they would ideally administer 250mg per injection. In case an individual administering 50mg per day of Dianabol would have to ideally ingest their doses once every 2 – 4 hours, which might work out to 2 administrations of 25mg per administration during the waking hours. 

Here are some additional practical dosage examples:

TESTOMED P 100 (Testosterone Propionate) half-life: 4.5 days. Optimal injection frequency: every other day (daily is even better).
TRENBOMED A 100 (Trenbolone Acetate) half-life: 3 days. Optimal injection frequency: every other day (daily is even better).
TESTOMED C 250 (Testosterone Cypionate) half-life: 10 – 12 days. Optimal injection frequency: twice per week, each injection split evenly between each other (for example, Monday and Thursday).
Testosterone Suspension half-life: 4 – 24 hours. Optimal injection frequency: once per day (multiple times per day is even better).
DIANAMED 10 (Methandienone) half-life: 4 – 6 hours. Optimal administration frequency: once every two to four hours.
If the user is maintaining steady and stable blood plasma levels with frequent administrations long before the anabolic steroid’s half-life period has ended, this fact also helps the user in performing a much more comfortable cycle that is void of side effects. Because peaks and valleys in blood plasma levels are avoided, the incidence of side effects becomes much lower. Side effects appear mostly during periods of fluctuating hormone levels, where the imbalance of different hormones takes its toll on the body.

Frontloading Steroids

Frontloading is the practice utilized by anabolic steroid users in an attempt to elevate blood plasma levels of the anabolic steroid as quickly as possible to experience gains and the ‘kick-in' period much quicker. This is usually done with long-estered anabolic steroids such as Testosterone Enanthate, Testosterone Cypionate, Deca-Durabolin(Nandrolone Decanoate) and others. All these anabolic steroids express fairly long steroid half-lives, meaning they tend to kick-in much later (a half-life of 7 days or longer is considered to be quite long). These long-estered anabolic steroids often require several weeks of administration (4 – 6 weeks) before performance and physique changes are experienced. This is so because the process of hormone release in the body is very slowly, due to the very long steroid half-lives, and therefore results in a very slow build-up to the optimal blood plasma levels that are required for significant gains to occur. The very interesting fact is that shortly after the injection of any compound, whether it is a short-estered anabolic steroid or a long-estered one, a sharp and fast release of the hormone in the body always occurs within the day or two following injection. Blood plasma levels rise quite rapidly before beginning to decline. With long-estered anabolic steroids, the build-up of the hormone to the intended optimal peak effective level is achieved slowly over time. For example, in the case then an individual wants to run a cycle of Testosterone Enanthate at 500mg per week, it should be considered that the body will not contain 500mg of Testosterone Enanthate until several weeks into the cycle if the user merely administers the only 500mg of Testosterone Enanthate from the beginning. The practice of frontloading avoids this by having the user administer double (or even triple) the originally intended dose within the first week (or first few days) of the cycle, depending on the anabolic steroid used.

Let’s use TESTOMED E 250 (Testosterone Enanthate) as the example compound, for an explanation, its half-life will be regarded as 7 days, the normal progression of blood level build-up would be:

Day 1: 500mg
Day 7: 250mg remaining from the previous injection + 500mg freshly injected = 750mg total
Day 14: 375mg remaining from the previous injection + 500mg freshly injected = 875mg total
Day 28: 437.5mg remaining from the previous injection + 500mg freshly injected = 937.5mg total
Day 35: 468.75mg remaining from the previous injection + 500mg freshly injected = 968.75mg total
Day 42: 484.38mg remaining from the previous injection + 500mg freshly injected = 984.38mg total

As we can see, it took until 42 days before blood plasma levels started to come very close to reaching the optimal 500mg per week level in the bloodstream. The amount to be concerned over is the amount that is remaining in the body before the next injection.

Let’s compare the frontloading method of double-dosing the intended weekly dose and how long it will take for optimal blood plasma levels of 500mg/week to be achieved:

Day 1: 1,000mg
Day 7: 500mg remaining from the previous injection + 500mg freshly injected = 1,000mg total
Day 14: 500mg remaining from the previous injection + 500mg freshly injected = 500mg total

It took almost 7 days before blood plasma levels of 500mg in the body are achieved with the frontloading method. By comparison, it would take 42 days for this dose to be achieved in the body by simply administering 500mg per week. By administering double the intended dose on day 1 (or in the first week) of the cycle, optimal intended blood plasma levels are acquired by the second week. The result is a faster onset of gains and performance and physique changes compared to the standard dosing method.

In general, with frontloading practice, most users will report their long-estered compounds to ‘kick-in’ approximately 3 or 4 weeks into their cycle compared to 4 – 6 weeks. The only possible downside to the frontloading method is a faster onset of side effects for the user, especially those more sensitive to them. Individuals who fall into this category must be aware and consider the possibility to avoid the practice of frontloading. Inexperienced users, who are brand new to a particular compound, might also want to avoid this practice.

List of Steroid Half-Lives

Below is the list of anabolic steroid half-lives (in alphabetical order):

SUSTAMED 250 (Sustanon): 15 – 18 days (variable due to the mixture of four different ester types)
WINIMED SUSPENSION 50 (Stanozolol Water Suspension): 24 hours

As a conclusion, that may be said, that an anabolic steroid half-lives and this is the same for any other drugs, chemicals, or foods: half-lives can vary, and only approximations and ranges can be given. Also, half-lives are very susceptible to the individual metabolism of the person using the drugs, as some individuals may possess a faster ability to metabolize hormones than others, while others can be much slower at this process. For example, while the half-life of Testosterone Enanthate is around 7 – 10 days, there might be some users that might metabolize the drug within 5 days and others that might metabolize it within 12 days or more.