Steroid Half-Lives

By: Juice

Last updated: is intended for informational purposes only and does not take the place of professional medical advice.

Have you ever really thought about exactly what’s going on from the moment a steroid enters your body? Like all drugs, anabolic steroids are complex and to fully grasp every detail of how they work you might want to have a chemistry degree.

Steroid Half-Lives
Steroid Half-Lives

But to understand the basic concept of steroid half-lives is something that all bodybuilders and performance users should have an interest in because it literally shapes the way we use these performance enhancing substances.

Once you have a solid understanding of steroid half lives you are going to be in a much more confident position when it comes to planning and implementing your cycles, as well as the critical post cycle therapy afterwards.

Author’s Note: The following guide is based on my personal experience and does NOT promote the illegal use of steroids (PEDs).

Steroid Half-Lives: A Simple Explanation

In the medical and pharmaceutical world, the half life of a drug is a concept of great importance and interest.

Scientists will often call this the elimination half life, because it refers to how long it takes for the substance to reduce to half of its original dose as your body gradually eliminates the substance.

Anabolic steroids are a substance that can be thought of in the same way as any other type of drug when it comes to half life.

Medical experts stick by this one rule: “Different drugs have different half-lives; however, they all follow this rule: after one half-life has passed, 50% of the initial drug amount is removed from the body.”

Each steroid will have a different elimination half life time and while it won’t always be an exact certain number, it’s a very wise idea to have an understanding of the half life of the anabolic steroids you’re using for three main reasons:

  • To be aware of how long the steroid will be at its peak level
  • To know how often you should be taking it to maintain that peak level
  • To plan when you should start post cycle therapy

The elimination half life of your steroid will be a critical factor in how you plan your cycles and how often you administer each steroid. It will also give you the ability to stack different steroids for the best possible results.

If you think you’ll have to undertake drug testing, the half life of a steroid will play a smaller role than you might expect. This is because many steroids can continue to be detected for many weeks or even months later thanks to advanced drug testing technology.

It’s not only to get maximum performance and results that makes understanding half life so important.

It’s also a matter of safety: inappropriate administration can at best result in more severe side effects or at worst can cause health risks like major stress to the liver. This can be avoided simply by being aware of the half life of each and every steroid you intend to use.

What Affects the Different Steroid Half-Lives?

The half life of any anabolic steroid is going to be influenced by different external factors. The two most influential are those which are introduced through the way the steroid is manufactured: the type of ester attached to the steroid hormone (esterification), and the route of administration of the steroid (most commonly either injectable or oral).

The third most important factor contributing to the steroid’s half life relates to how quickly it is metabolized by the body.

Route of Administration

The majority of anabolic steroids are taken either through injection or through a pill in oral form. While medical use of testosterone can include patches or gels, these forms are not thought to be useful for athletics and bodybuilding purposes.

Oral administration of steroids almost always results in a very short half life – the steroid will start working quickly and exit the body in a short time. The half life of some oral steroids can be as short as just a few hours.

Unlike injectable steroids which have an ester attached to the control the release rate of the hormone, most oral steroids have no ester; it is simply the hormone on its own which is immediately released upon ingestion after passing through the liver (this is what also makes most oral steroids toxic to the liver). The activity of liver metabolism also contributes to the more rapid metabolism of oral steroids.

In comparison, injectable steroids can be customized through the attachment of an ester to the steroid hormone. Some steroids, like testosterone, are available in multiple different esters of different sizes and this influences the speed at which the hormone is released after injecting.

All injectable steroids are created in either an oil or water based solution and this goes some way in contributing to the release rate due to the way a depot is formed in the tissue where you inject the steroid, and from here the steroid releases into the bloodstream.

This depot process contributes to a great extent to the steroid’s half life, but still not as significantly as esterification which we could say is the most important factor.


The attachment of an ester to a steroid hormone can slow down its release rate into the bloodstream and it’s this process that will play the greatest role in controlling the different steroid half-lives.

As I’ve mentioned already, oral steroids will normally have no attached ester and as a result they are immediately active in the body at the full dose after passing through the liver.

Injectable steroids will release a more slow and steady amount of the hormone and it’s the attached ester which controls this process.

Esterification is a chemistry process of bonding a compound to the hormone and the length of the attached carbon chain will determine the half life of the steroid – a longer chain extends the half life, while short chain esters create an injectable steroid with a shorter half life.

Therefore, this will be a shorter acting effect that requires more frequent injections to maintain a level of the hormone that’s compatible with achieving the types of physique changes and performance benefits (think strength and endurance increases) that bodybuilders expect.

While there are a large number of esters that have at some point been attached to steroids, only a relatively small number retain their popularity and use today. This is both due to availability as well as their effectiveness.

When using a basic testosterone steroid, it’s the ester that will control how you experience the hormone’s effects. After all, testosterone is exactly the same steroid regardless of the attached ester, but the ester will control testosterone’s half life and active life in the body.

This ranges from the very short half life of Testosterone Propionate at just a few days, up to the commonly used Testosterone Cypionate with a half life of over 10 days.

Esterification is therefore the number one factor in influencing the half life of a steroid; in fact that’s the main purpose of attaching an ester – to extend the active life of the steroid hormone.

Resistance to Metabolism

While not as dominant a factor as esterification and the route of administration in contributing to a steroid’s half life, just how resistant each steroid is to the body’s natural metabolic processes is going to play a role in how quickly it will be broken down.

A faster break down by the metabolism will contribute to a shorter half life in addition to the other factors already mentioned above.

Your metabolism is going to be different to the next person, so this factor will by no means be universal in terms of how much it speeds up the break down and elimination of the steroid from your body.

Your own metabolic process is going to be influenced by different factors like:

  • your age
  • your health condition; in particularly your liver and renal health
  • use of any other medications
  • nutrition
  • genetics

So while some people might be slightly more resistant to a quick metabolic breakdown of steroids, the time difference is negligible and ultimately like any other drug, steroids will always eventually be eliminated from the body.

What Steroid Half-Lives Do?

The half life of a steroid gives you a method of working out how long that steroid is going to remain active in your system at a level where performance and physical benefits will be noticeable and achievable.

At the practical level, it’s the half life of the steroid (or steroids) you plan to use in a cycle that will need to be considered when you’re planning the structure of your cycle – everything from how to combine different steroids, how often to take each one, where to place them within the cycle, and when you will start PCT after the cycle ends.

Because us bodybuilders will always aim to maintain a stable and optimal level of the steroid hormone in the bloodstream, administering a steroid more frequently than its half life would normally require if (for example) the steroid was being used as a testosterone replacement medical treatment.

For performance enhancement, we will rarely want to wait until the steroid’s half life is reaching a close point as that’s when you’ll experience a drop in blood levels of the steroid, and a decline in consistent performance effects.

Because our main goal is to achieve a massive boost to strength and muscle gains (as well as other benefits), bodybuilding use of steroids comes in at the extreme end as compared to medical use – put simply, we push the barriers away and take steroids at a much higher frequency (and dosage) than their half lives would normally dictate.

How to Properly Structure Your Cycles

The elimination half life of each steroid you plan to use in your cycle is going to determine how often you need to take your dosage; whether that be your entire weekly dosage or in some cases splitting the dose up into multiple administrations each week.

So you can start to see just how important it is to be familiar with the half life of each compound you use, even if you’re going with just a one single compound cycle.

A common error is to assume that the half life of a steroid is a firm and unchangeable number. In reality, each steroid’s half life is an estimate only.

In some cases you will see a range of hours or even days estimating a half life; this is because individual factors like metabolism will always cause variations.

After you gain some experience using a particular steroid, you’ll get a good idea of when you feel the benefits decreasing and you’ll then be able to more precisely plan your cycles to gain maximum benefit from each steroid.

But in most cases, following the recommendations of experienced users in terms of frequency of administration is still likely to give you the best results – after all, most of the best anabolic steroids have been in use for many decades and hundreds of thousands of people have already worked out the very best way to use them so there’s little reason to try and reinvent the wheel.

Structuring your cycle will involve considering the half life of each and every steroid being used. The goal is to administer each dose well before the half life time occurs – otherwise you will reach a point where benefits decrease.

Your steroid cycle structure might need to include either a kickstarting compound or the process of frontloading. This will be important where you’re using one or more slow acting (long ester) steroids that have long half lives.

Without a kickstart or frontloading, you will be waiting weeks to see results with steroids like Deca-Durabolin and Equipoise which are well known for their long half lives.

Frontloading Steroids

As bodybuilders who use steroids, one of our highest priorities is to maintain a high and constant blood plasma level of any and all steroids being used in a cycle.

When you’re using one of the slow acting (long estered) steroids it results in slower build up of the steroid over a longer period of time and therefore: slower results.

One common strategy to deal with this is to include a fast acting steroid at the start of the cycle (usually an oral steroid) which acts as the main anabolic agent while your slower steroids take time to kick in. This is a kick-start strategy.

But a more advanced and potentially even more effective strategy is to do frontloading.

The main goal of frontloading is to get your blood levels of a steroid up to an optimal level as fast as possible. This of course lets you benefit from quicker performance effects and gains.

Mostly we will do frontloading when using slower acting steroids that have a longer half life like some of the popular testosterone esters including Testosterone Enanthate and Testosterone Cypionate.

Because these steroids can take a couple of weeks to start delivering effects, frontloading is an ideal strategy.

When frontloading you will twice or even three times your regular dose within the first week or so of using the steroid. This allows you to take advantage of the natural quick spike in hormone release upon injection, which then slows down afterwards and becomes more gradual.

Frontloading will amplify this initial effect early on, and allow you to benefit sooner from increased performance.

Normally if you were to use Testosterone Enanthate at 500mg weekly (a standard dosage) it can take well over one month for your blood levels to actually reach the point of 500mg of the steroid. Increasing the dose is not always the best option, because you’ll then be dealing with additional side effects.

Frontloading Testosterone Enanthate can get your blood plasma levels up to the 500mg level much quicker and this involves taking a double dose of 1000mg on the first day (or whatever will be double the amount of your chosen regular dosage).

On day 7 you then take 500mg. By this time there will be about 500mg of the first dose in circulation, getting you back up to 1000mg. Then continue the cycle with 500mg per week and this means you don’t have down time at the start of the cycle while waiting for Testosterone Enanthate to reach its peak level.

With this frontloading method comes both faster results, but also a more rapid onset of side effects at the beginning of the cycle.

If you’re particularly sensitive to androgenic and other side effects, frontloading might not be for you but it does provide an additional option for those who prefer not to undertake a kickstart using an oral steroid.

List of Steroid Half-Lives

The following table contains the most popular/commonly used anabolic steroids with their half-lives:

CompoundActive Half-Life
Anavar9 hours
Anadrol8 to 9 hours
Winstrol9 hours
Winstrol Depot1 day
Dianabol4.5 to 6 hours
Deca-Durabolin15 days
Sustanon 25015-18 days
Testosterone Cypionate12 days
Testosterone Enanthate10.5 days
Testosterone Propionate3-4.5 days
Testosterone Suspension1 day
NPP4.5 days
Trenbolone Acetate3 days
Trenbolone Enanthate8 days
Parabolan14 days
Omnadren15-18 days
Clenbuterol1.5 days
Proviron12 hours
Masteron3-4 days
Superdrol6-8 hours
Halotestin9.5 hours
Primobolan Oral2-3 days
Primobolan Depot10.5 days
Equipoise14 days
Turinabol16 hours
Clomid*5-7 days
Nolvadex*7-14 days
Arimidex*2-3 days
Letrozole*2-4 days

Note: Clomid, Nolvadex, Arimidex and Letrozole are ancillaries usually used during a post-cycle therapy (PCT).


Which anabolic steroid has the shortest half-life?

Oral steroids will have a much shorter half life than injectables because they have no attached ester. Dianabol has the shortest half life of anabolic steroids commonly used by bodybuilders. It’s half life can be as short as 4.5 hours and usually no more than 6 hours.

Many users will take Dianabol twice daily to prevent blood levels dropping. Because of its short half life, Dianabol works quickly and so is often used to kick start a cycle.

How long does it take for testosterone levels to return to normal after a cycle?

Different testosterone esters will have different half lives, and combined with other factors such as your individual health it will usually take up to 3 months for testosterone function to get back to normal if you don’t do PCT.

Unless you don’t mind suffering with low testosterone, PCT is essential but the half life of your steroids will determine at what point you should start PCT after your cycle ends.

What testosterone steroid has the shortest half-life?

The testosterone ester with the shortest half life is Testosterone Propionate with an approximate half life of 4.5 days so it requires frequent injections. Most bodybuilders will inject this form of testosterone every two days, but some will even inject a smaller dose daily to maintain a high blood level.

What anabolic steroid has the longest half-life?

Any steroid with the Undecanoate ester will have a very long half life of over 16 days, but of the more commonly used steroids, Equipoise and Deca-durabolin both have the longest half lives at around 14-15 days.

This means they are slow acting steroids which take a long time to kick in, and may require frontloading if you want a more rapid onset of their benefits at the start of your cycle.

How long do steroids stay in your system?

Every anabolic steroid will have a different amount of time that it takes to leave your body.

The half life of a steroid can range anywhere from a few hours to two weeks but that doesn’t mean the steroid is completely our of your system once the performance effects come to an end.

Many steroids can still be detected weeks or even months later so it’s important not to confuse the half life of a steroid with its detection time.

What is the half life of Trenbolone?

Trenbolone is one of the most popular steroids but many people don’t realize there’s more than one Trenbolone ester.

The most common is Trenbolone acetate which has a half life of three days. There’s also Trenbolone enanthate which, like Testosterone enanthate, has a longer half life of between 7 and 10 days.


The repeated process of elimination half life, where the steroid continues to halve its concentration in the body until it no longer has effect, applies to all types of drugs and even vitamins and foods. It’s a complex chemistry concept which we can nevertheless understand at its basic level.

The route of administration (oral or injection) and resistance to metabolism are key factors, but the foremost factor in determining steroid half life is esterification and while some steroids are only available in one ester type, others have many to choose from so it’s worth taking the time to compare different esters.

You can see just how central a role the half life of a steroid plays in everything from how you stack different steroids, to how you choose particular esters and ultimately how you plan and organize your cycles and your PCT.

So while it’s easy to overlook the importance of steroid half-lives, it’s actually the one thing that you WILL want to have solid knowledge on and your experience with steroids will be a much more satisfying one as a result.

About the Author
Juice Lewis, Author of
Juice Lewis

Real-life Experience, not Theory

I don't claim to know everything; what I talk about here is something I've done. From anabolic steroids to HGH, to peptides, insulin, and supplements, I've done it at some point in my life, and I can relate.