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Testosterone isobutyrate

As we all know, there are many different types of testosterone, such as oil based, water based, no ester, short esters, long esters, and even oral versions.  However, this particular type of testosterone, Testosterone Isobutyrate (Agovirin Depot), is the one that you will be surprised to learn about because of the way it behaves when injected, and the way it is administered.

agovirin depot

Fig 1. Agovirin Depot

Table of Contents


Let us first take a look at the history behind this compound, and its purpose, so we can understand the background.  The injectable testosterone isobutyrate in microcrystal suspension form first came around in the early 1950's.  It was supposed to be an injectable form of testosterone that would be slower acting than suspension or propionate, both of which were very popular at the time.

Unfortunately, once the enanthate ester came around several years later, this idea became obsolete, as the "E" ester became the dominant form of testosterone.

Today, Testosterone isobutyrate (Agovirin Depot) is made by Biotika in Eastern Europe.  It is mainly used to treat low androgen males, anemia, Cushings syndrome, and several other medical conditions, including adolescents with delayed puberty.

Background and facts

Now that we understand the history, we can discuss what makes this compound so interesting.  The Isobutyrate ester of this form of testosterone comes in a water base, just like the suspension.  Even though both are water based, they are different in their action mode.  For instance, the suspension is very fast acting and short lived, so it requires daily injections.  Meanwhile, Testosterone isobutyrate has a much slower release rate, and only requires an injection every 1-2 weeks.


The secret to Agovirin Depot is that it is designed to sit in muscle tissue and release very slowly after being injected.  This sounds like a great thing for those who do not want to inject very often, but there is a catch to this.

The first issue is that you need to use a thicker needle with this form of testosterone.  Remember, as the gauge size goes lower, the thicker the needle gets.  For instance, insulin needles are usually 29-30G, and when you go to draw blood it is a thick needle they use - 17-18G.  However, with this compound you will need to use a thicker needle at 21G, which is the recommended size, otherwise the injection will be very slow.

The second issue is that Agovirin Depot comes exclusively in 2ML amps that contain only 25 milligrams (mg) of the steroid.  As a result, you will need to plan on a lot of injecting in order to get in enough active substance that is necessary to dose at bodybuilder amounts.

Side effects

Testosterone isobutyrate has the same side effects as any other testosterone form.  The first side effect that must be addressed is the aromatization into estrogen, which can be counteracted with an aromatase inhibitor (AI).   Otherwise, such side effects as gynecomastia (bitch tits), water retention, bloating and the domino of side effects such as insomnia and high blood pressure will occur.

Furthermore, there are the typical side effects associated with any androgen hormone.  For example, aggressiveness, libido changes, and lipid strain are all possible.  To help with this, we recommend you use a support supplement, such as N2Guard.

And finally, just like with any anabolic androgenic steroid (AAS), you will shutdown exogenous hormones, meaning that your pituitary glands will no longer produce testosterone on their own.  This is why it is essential to run a proper post cycle therapy (PCT) after ending the testosterone run.

User results and cycle ideas

Users will experience gains in mass and strength typical of testosterone.  For mass gains you can choose to stack this compound with Trenbolone, Deca Durablin, Dianabol, or Equipoise.  What's more, you can simply use Agovirin Depot as your testosterone base of any steroid stack.  An aromatase inhibitor, such as aromasin, is necessary throughout the entire cycle.

Half life

Since it is so slow acting, Testosterone Isobutyrate's half life is quite long at around 15 days.


The biggest problem with Testosterone isobutyrate (Agovirin Depot) is that in order to get due results the dosage must be in the same range as any other testosterone - between 250-1000mgs per week.  As mentioned, the ampules come in such tiny amounts of mgs per ml, that users will have to make multiple injections in different muscles with thick needles every few days to be able to take full advantage of this compound's properties.  Logically, this can get very stressful, painful and annoying.
For this reason Testosterone Isobutyrate has never been popular in bodybuilding circles.


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Written by
Steve Smi (Also known as Steve Smith), has over 12 years of experience in the bodybuilding and fitness industry. He's the co-Host of the popular Evolutionary Radio Podcast - over 500,000 listens! He has been a personal trainer and writer for the last 10 years with over 1000 articles written. He's been a moderator on forums for over 10 years. Steve holds the following certifications and records: NASM Personal Trainer NASM Fitness Nutrition Specialist Florida Local Powerlifting champion Top writer for 2019 Fitness rated

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