Nandrolone Phenylpropionate

Most commonly referred to as ‘NPP’, Nandrolone Phenylpropionate is, in its simplest form, a quick-release version of Nandrolone Decanoate. Quite similar in the way that Testosterone Propionate is related to longer-acting testosterone. 

NPP is often injected twice per week, deep into the muscle tissue. The initial spike and half-life is much shorter than deca and can bring on gains in mass and strength much quicker. Most users report an increase in strength around the week 3 – 4 as opposed to week 4 – 6 with deca.

NPP is often used in maintenance or cutting cycles. Due to the frequency of injections, 2 – 3 times per week,  it is often much less hassle to stick with deca.

Nandrolone Phenylpropionate

New users can expect to see substantial gains in mass and strength in a relatively short time. NPP is a very versatile performance-enhancing drug and can be used in cutting cycles and by strength athletes.


NPP is often supplied in vials of 100mg. Depending on the country of origin, you can also find it in 50mg/ml dissolved in a carrier oil. 

NPP is very rare to be found in pharmaceutical grade, as such it is manufactured by many underground labs.

NPP Cycles

NPP is often used when athletes want a short-acting drug which can boost performance and be out of the bloodstream much quicker than traditional esters. For lean mass cycles, it can be run alongside testosterone propionate or Winstrol for lean mass and strength.

Typically NPP cycles are ran at around 200 – 400mg per week. This is enough to see significant gains in strength and size.

Because of the pinning cycle cycles will be around the 6 – 8-week mark. If users are planning to run a longer cycle then more often than not they will use deca.

Beginner NPP Cycle

Weeks 1 – 8

  • Monday 1 x 100mg injection NPP / 1 x 100mg of Test Prop
  • Thursday 1 x 100mg injection NPP / 1 x 100mg of Test Prop
  • AI (Aromatise inhibitor)
  • Weeks 9 – 11 PCT

More experienced NPP Cycle

Weeks 1 – 8

  • Monday 1 x 100mg injection NPP / 1 x 100mg of Test Prop
  • Wednesday 1 x 100mg injection NPP / 1 x 100mg of Test Prop
  • Friday 1 x 100mg injection NPP / 1 x 100mg of Test Prop
  • AI (Aromatise inhibitor)
  • Weeks 9 – 11 PCT

Advanced NPP Cycle

Weeks 1 – 8

  • Monday 1 x 100mg injection NPP / 1 x 100mg of Test Prop
  • Wednesday 1 x 100mg injection NPP / 1 x 100mg of Test Prop
  • Friday 1 x 100mg injection NPP / 1 x 100mg of Test Prop
  • 50mg Winstrol everyday
  • AI (Aromatise inhibitor)
  • Weeks 9 – 11 PCT

How To Inject Nandrolone Phenylpropionate

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

What Are The Side Effects of NPP

Any drug can have side effects and steroids are no different. Side effects of Nandrolone can come in various forms and are usually more prevalent for people who run continued length cycles or use more substantial doses.

What Are The 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 steroids into the following subjects;

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

Androgenic Side Effects Of NPP

Many people wrongly assume, because NPP has a low androgenic rating, the androgenic side effects would be little or non-existent.  

Many people cycling NPP, though.  Have reported large breakouts of acne, especially on the back, oily skin and increased growth in body and facial hair. There is also the possibility of progesterone increasing which can cause gynecomastia.

Nandrolone is also notorious for reducing libido in men. Many users report softer erections or the inability to climax while running a 19-nor compound.

Estrogenic Side Effects

Technically speaking, nandrolone converts to estrogen at a much lower rate than testosterone. However, users running larger doses or running multiple compounds have and continue to have to control and manage estrogen.

Estrogen is the primary sex hormone for females. This can cause an abundance of unwanted side-effects in men.

Estrogenic side effects of nandrolone phenylpropionate can include water retention, an increase in body fat and gynecomastia. Estrogenic side effects can be controlled using compounds such as Nolvadex, Aromasin or anastrozole. 

Nandrolones have also been known to increase progestin levels. The increased progestin in the body can lead to increased fat storage and breast tissue growth in men. These side-effects can occur even if estrogen levels are kept under control.

If you suffer from these effects using compounds such as Cabergoline can help to reduce and stop them.

Cardiovascular Side Effects

Steroids can increase muscle mass as well as causing the user to hold more ‘water weight’. This additional weight is often built up in short spaces of time and can result in added strain on the heart and organs.

Cardiovascular Side Effects

NPP 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.

The increase in muscle mass and water weight can also lead to higher blood pressure which can again, affect the heart and kidneys.

Running NPP can also affect your blood ‘thickness’. 

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 NPP affect the liver?

Nandrolone decanoate is not reported to have any direct effects on the liver for healthy individuals.

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 NPP

  • Huge mass and strength builder
  • Quicker acting than regular deca
  • Great for aching joints
  • Can deliver quality muscle gains when ran alongside test or Winstrol
  • Can clear out the system much quicker