What is Primobolan

What is Primobolan?


Primobolan or primo, as it is more often known, is a performance-enhancing drug which has been on the market since the ’60s. Primo has often been overlooked due to its mild gains and expensive price tag, however, when used at higher doses it does offer great gains in lean muscle.

Many people who prefer to run cycles with minimal side effects prefer the subtle, yet effective, gains that come when running a Primobolan cycle. Users can often expect to make small gains, with the majority being lean muscle with little to no water retention.

The enanthate ester attached to Primobolan give it a release cycle similar to other enanthate bound steroids like testosterone E. The most effective administration cycle is injecting twice per week for the duration of the cycle.

Methenolone enanthate, Primo, is an extremely versatile steroid and can be stacked amongst many, if not all, performance-enhancing drugs. It can be used with cutting and bulking cycles, however, given its cost most people will run it pre-contents or pre-summer for regular gym-goers.

The mild nature of Primo makes it a great option for people who are more susceptible to side effects, especially estrogen-based. Primo should not convert to estro and as such should present little to no effects on people sensitive to estrogen sides.

Androgenic Rating: 44-57

Anabolic Rating: 88

Primobolan steroid cycle primobolan muscle
Primobolan by Bayer


Methenolone enanthate is manufactured by UGLs and is also available in pharma grade. The strength can vary from lab to lab, however, it is most commonly found in a dose of 100mg/ml.

How Much Does Primobolan Cost?

Primobolan is one of the most expensive PEDs on the market. The cost of raws and limited availability makes it much sought after and also drives up the price.

An average price range for purchasing from an underground lab can be from £45 per 10ml vial up to £75.

What Does a Primo Cycle Look Like?

Primo cycles are usually very mild. Commonly, Primo is run alongside testosterone for around 12 weeks. Many people do prefer running primo for longer durations, to make the most out of this mild steroid.

The high costs and limited availability of primo make it a bit of a struggle when deciding on how much and how long to run. More often than not anyone planning a cycle may opt to just run higher testosterone or deca alongside instead of spending the extra money on Primo.

There is also the problem of Primo being available only in a dose of 100mg/ml. That means for a significant cycle the user would need around 4-5ml per week, plus to see a return in gains to make it worthwhile. That can push costs of running a 12-week cycle up to and over £500 – £800.

As with anything to do with performance-enhancing drugs, not everything works for everyone. It is important to listen to your body and see what works for you. 

Beginner Primo Cycle

Weeks 1 – 12

  • Monday 1 x 100mg Primobolan / 1 x 200mg Testosterone
  • Thursday 1 x 100mg Primobolan / 1 x 200mg Testosterone
  • AI (Aromatise inhibitor)
  • Weeks 12 – 14 PCT

More Experienced Primo Cycle

Weeks 1 – 12

  • Monday 1 x 150mg Primobolan / 1 x 250mg Testosterone
  • Thursday 1 x 150mg Primobolan / 1 x 250mg Testosterone
  • AI (Aromatise inhibitor)
  • Weeks 12 – 14 PCT

Advanced Primo Cycle

Weeks 1 – 12

  • Monday 1 x 250mg Primobolan / 1 x 400mg Testosterone
  • Thursday 1 x 250mg Primobolan / 1 x 400mg Testosterone
  • AI (Aromatise inhibitor)
  • Weeks 12 – 14 PCT

How To Inject Primobolan

For a step by step guide on how to safely inject Primo please see this article ‘How to inject steroids safely’.

What is primobolan
Primobolan by Balkan Pharmaceuticals

What Are The Side Effects of Primo

Any drug can have side effects and steroids are no different. Side effects of Primo can come in various ways, however, it is one of the mildest steroids on the market when it comes to being affected by and managing side effects.

Side effects from steroids can affect the cardiovascular system, estrogenic and androgenic.

When using anabolic/androgenic steroids, it is essential to understand the risks associated with the use and also how to minimise the chances of them occurring. 

It is important to note that not everyone will experience side effects from steroids. It is essential to know and understand the risk associated with them, though. 

We can break down the side effects of Primobolan into the following subjects;

  • Estrogenic side effects
  • Androgenic side effects
  • Cardiovascular side effects
  • Hepatotoxicity
  • Natural testosterone shutdown

Androgenic Side Effects Of Primo

Methenolone enanthate is actually an anabolic steroid, yet it does have the power to produce androgenic side effects. Some users can still suffer from oily skin, breakouts on the back and shoulders as well as deepening of the voice and an increase in body hair growth.

If you suffer from male pattern baldness it is possible Primobolan will increase the rate at which you are losing hair.

Estrogenic Side Effects

This is what makes Primo quite attractive to first-time steroid users, and those who wish to keep side effects to a minimum. Primo does not and should not exhibit any estrogenic side effects. Now, if it is being run alongside another compound which can aromatize then obviously you would need to manage that with an AI.

However, if being run alone, you should need not worry about water retention and gynecomastia, or any side effects related to water retention or aromatization.

Cardiovascular Side Effects

Primo can affect cholesterol levels by reducing HDL or ‘good cholesterol’ and increasing LDL ‘bad cholesterol’. This shift, over time, can result in the hardening of the artery walls and higher levels of fat in the bloodstream leading to strokes, or heart attacks if left unchecked and untreated.

Primo will have a minimum effect on blood pressure due to its low rate of water retention and ability to promote lean muscle gains, not bloat or mass.

Running Masteron can also affect your blood ‘thickness’, by increasing your red blood cell count. 

It is highly recommended for anyone thinking about running a cycle, or who has already run one to get blood tests done at least every three months. This not only allows you to know what is going in regards to your health but also make any necessary adjustments before starting.

Does Primobolan affect the liver?

Running Primo should not have any direct impact on the liver.

It is important to note, though, high dose cycles or prolonged cycles could push liver markers beyond normal levels.

Natural Testosterone Shutdown 

Using any form of steroid will lead to the suppression of your natural test production. This often returns after the cycle has stopped. In rare cases or when users have been on cycle for prolonged periods, people can be shut down permanently or suffer from low testosterone levels for many years.

PCT ancillaries such as HCG can help keep the testes stimulated and producing natural testosterone. It is usually taken as a part of a PCT (post cycle therapy).

Benefits of using Primobolan

  • Great for lean muscle gains
  • Very low chance of side effects
  • Works fantastic on people with low body fat
  • Great synergistically when ran alongside other PEDs


If it is sheer mass and strength you’re after then Primobolan probably isn’t going to be your number once choice. However, it does have its place in the bodybuilding world.

Rumoured to be a favourite of many old school bodybuilders, Primo is a great choice for those looking to enjoy a cycle without having to worry about taking extra precautions to minimise and counter side-effects.

Anyone running primo can expect to gain nothing but lean mass, with little to no bloat. The flipside, however, is the volume of oil needed to produce those gains. Some can use a few ml a week where other people report needing 5-6ml to see significant gains.

Running Primo alongside testosterone makes it much more appealing and also means you can get away with not having to take out a second mortgage on your home. 


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