AAS – Anabolic Androgenic Steroids

Anabolic-androgenic steroids (AAS) are synthetically produced variants of the naturally occurring male sex hormone testosterone. All steroids have both anabolic and androgenic properties but the ratio varies across the range of steroids. Some steroids are more androgenic than others.


A condition brought on by excess growth hormone. This may cause the jaw bone or forehead to protrude and the hands and feet to swell. Other side-effects can include carpal tunnel syndrome (compression of the nerves in the wrist causing numbness or weakness), sleep apnoea and cardiomyopathy.

Adipose tissue

Also known as body fat, this is the layer of fat just below the skin.

Amino acids

The building blocks for all proteins. For further information please see Diet.


A small, sealed glass bottle. Ampoules need to be snapped open as they are completely sealed to keep them sterile. Needle exchanges carry “amp snappers” that are specifically designed to snap open ampoules safely. It is important to note that an open ampoule will have an exposed edge of broken glass that may be sharp. It is also important to note that an ampoule that has been opened is no longer sterile and should be used immediately. Do not store open ampoules.


This is the growth and development of tissue (ie: Muscle tissue). It is the opposite of catabolic.


A group of hormones (either natural or synthetic) that influence the development of the male reproductive system and other male qualities (Deepening of the voice, facial hair etc).


When referring to anabolic androgenic steroids; the term ‘androgenic’ refers to how much the steroid influences the secondary male characteristics. The more androgenic a steroid is said to be, the more likely it is that you will experience side-effects using it. The more androgenic a steroid is, the more likely it is to aromatise. (See aromatisation)


How androgenic a substance is.

Androgen receptor

All cells within the human body have receptors; these are places in, or on, the cell where a hormone can interact with the cell. Receptors are often compared to a lock, with the hormone being a key. You need the right hormone to interact with each type of receptor. The androgen receptor specifically interacts with androgens such as testosterone.


A drug that is used to prevent the conversion of testosterone into oestrogen or to block the action of oestrogen in cells.


When testosterone levels rise above a certain point (which varies between people), the aromatase enzyme acts upon the excess testosterone to convert it to oestradiol, a form of oestrogen.

Aromatase inhibitor

A drug used to prevent the conversion of testosterone into oestrogen.


Bacteriostatic Water

Sterile water that has a precise amount of benzyl alcohol added to it to slow down bacterial growth. Sterile water is usually supplied in small ampoulesof 1-2ml in size. These are generally suitable for single use. Some products however, will need more water than this or may need to be stored once they have been reconstituted and bacteriostatic water is more appropriate for this. It is important to note that bacteriostatic water will not completely stop bacteria from growing in the water; it merely slows down how fast the bacteria can grow. Powder products reconstituted with bacteriostatic water should be stored in a fridge, out of reach of children and young people, and used within 3 days.

Bitch Tits

Slang term used to describe gynaecomastia, derived from the perceived similarity in appearance between gynaecomastia and the teats of a female dog.

Black Market

The illegal distribution or sale of drugs, often associated with counterfeit substances.

Blast & Cruise

A particular form of steroid cycle in which the user takes typical bodybuilding doses for a set period of time (the “Blast”), much like conventional cycles, followed by a similar period using smaller doses (the “Cruise”) before repeating the higher dose cycle. Typically, people using this approach will repeat this process for several months or more. There is no scientific evidence to support this approach.
Even the lower doses used in a typical Blast & Cruise approach are far beyond natural levels. Without taking time off, the body cannot return to a natural state and there is a much greater risk of serious side-effects developing. Specifically, the longer you stay “on” the more likely you are to experience side-effects and the more likely those side-effects will be serious. It is not advisable to maintain AAS use for such an extended period of time.



A food source (macronutrient) that the body uses to make glucose, to fuel all biological processes. For more information see Diet.

Cardiovascular disease (CVD)

This is a general term to describe a disease that affects the heart or blood vessels. There are four main types of CVD; Coronary heart disease, stroke, aortic disease and peripheral heart disease. Cardiovascular disease is the leading cause of death in the UK and worldwide. Some studies have shown a relationship between the use of anabolic steroids and CVD. Specifically; the longer anabolic steroids are used for, the more likely one is to develop a form of CVD.


Cardiomypoathy means “heart muscle disease” and is defined as a deterioration in the function of the heart muscle, often leading to heart failure. The long term use of human growth hormone and anabolic steroids can lead to a particular form of cardiomyopathy known as “hypertrophic cardiomyopathy”. This is where the wall of the left ventricle (a chamber in the heart) thickens and grows as a result of the hormone use. Cardiomyopathy can lead to sudden cardiac death and is a common cause of death amongst young athletes. Some forms of exercise can also thicken the left ventricle and it can be difficult for doctors to distinguish between a normal, healthy response to exercise and a potentially fatal medical condition. If you have any family history of heart disease, it is advisable not to use IPEDs or, if you do use them, to leave plenty of time between cycles in order to allow the body to acclimatise and recover.


The breakdown of tissue and reduction in muscle mass, opposite to anabolic. Catabolism often occurs in disease, infection and long term immobilisation.

Circuit training

Going from one short exercise to another in quick succession which keeps the pulse rate high


Products that are sold as genuine branded products but are in fact, fake. With IPEDs, this refers to products that  are sold as genuine pharmaceutical products but are not. Many popular IPEDs are faked in this way so it is important to check the product before use. Genuine pharmaceutical products will always have the following:

  • A batch number and date printed on the box or bottle. This will be printed in a different font to the rest of the packaging as it is added at the point of manufacture.
  • An advice sheet that clearly describes what the product is, how strong it is, who it is intended for and how it is to be used; along with any warnings about side-effects. For some generic medicines (such as aspirin) this may be printed on the box.
  • If the box contains several ampoules (small, single-use, glass bottles) then each ampoule will be absolutely identical. The markings, the amount of liquid inside, the colour of the liquid and how well the liquid flows (viscosity); will all be identical.
  • None of the printing should rub off or smudge.

Often, the batch numbers can be checked on the pharmaceutical company’s website to ensure they are a genuine product. If in doubt, do not use the product as it may contain something other than the drug listed on the label or it may be stronger than the label suggests, leading to greater and possibly unknown, side-effects.


Creatine phosphate exists in the body in the muscle cells. As the muscles are worked, they use a fuel provided by the body called adenosine triphosphate (ATP) which splits into adenosine diphosphate (ADP) to provide energy to the cells. Creatine is then used to turn the ADP back into ATP for use by the cells again.  This is why bodybuilders and other strength athletes use Creatine as a supplement. It increases the amount of available “muscle fuel”. It is important to note that this energy cycle is one of three that the body uses, and only fuels short-burst activities like lifting weights or sprinting. Longer duration exercise is fuelled by carbohydrates or fat, depending on the type and length of exercise.


Cholesterol is a fatty substance (lipid) that is vital for normal functioning of the body. We get cholesterol from certain foods, but we also make some in the liver. Cholesterol is carried around the body by small proteins called Low-Density Lipoprotein (LDL) and High Density Lipoprotein (HDL); LDL carries cholesterol from the liver to cells that need it, whilst HDL carries cholesterol from the cells and back to the liver to be broken down. If too much cholesterol is carried out to the body, it starts to build up in arteries, restricting blood flow and causing disease in the artery. This is why LDL is known as “bad” cholesterol.


A bronchodiltor prescription medicine used in the treatment of asthma. For further information see Profiles of Commonly Used IPEDs.


A regime or course designed by the individual outlining which steroids are to be used, and in what dose as well as timescale of use – usually 8, 10 or 12 weeks. For further information see Cycles & Post Cycle Therapy.



A substance that encourages the body to reduce water retention, usually results in an increase of urine output.


Slang name for Methandrostenolone, also known by the trade name Dianobol. For further information please see Profiles of Commonly Used IPEDs.


Slang name for Nandrelone Deconate also known as Deca Durabolin. For further information please see Profiles of Commonly Used IPEDs.

Dihydrotestosterone (DHT)

A more potent form of testosterone which is responsible for several androgenic effects including: facial hair, genetic balding and male reproductive organ development. About 5% of the testosterone produced naturally is converted to DHT. Some anabolic steroids (ie: WinstrolAnavar) are made from DHT instead of testosterone.


Diet refers to nutrition and the intake and balance of carbohydrates, proteins and fats that will support the increase in energy used and development of the body. Lack of well planned and executed diet will significantly reduce the potential gains.  Diet is the single most important aspect of changing your physique. For further information see Diet.


Endocrine system

The body’s control system composed of a group of glands that maintain a stable internal environment by producing chemical regulatory substances called hormones. The endocrine system consists of the pituitary gland, thyroid gland, parathyroid gland, adrenal gland, pancreas, ovaries and testes.


Endogenous means “made by the body”. So endogenous testosterone is the testosterone naturally made by the testes.


An ester is a small molecule added to testosterone to change the speed at which it enters the blood stream. When you inject an anabolic steroid, it is pharmacologically inert. It will not do anything in the form that is injected in. Your body has to remove the ester to free the active ingredient (usually testosterone). The longer the ester, the slower the drug is released into your body. It also affects how long the drug is active for. A short estered  anabolic steroid (like Testosterone Propionate) will only be active for a few days, whereas a long ester (like Testosterone Enanthate) will be active for much longer. This can affect the way the drug acts within the body and also how you plan your post cycle therapy.


Street term for the veterinarian drug Boldenone Undeclynate also known as Equipoise


Enzymes are chemicals made in eth body that help chemical reactions to take place in cells. For instance; the aromatase enzyme is responsible for converting testosterone to oestradiol.


Originating outside the body. An injected synthetic steroid is an exogenous source of that hormone.


Fat Burners (Thermogenics)

These refer to a range of substances that are claimed to assist in the process of fat loss, typically by increasing energy use (which in turn raises body temperature) and by reducing appetite. Most of these substances are stimulant based and as such can carry a wide range of potential complications. For more information please see Fat Loss.

Follicle-stimulating hormone (FSH)

A hormone found in humans and other animals. It is made by the anterior pituitary gland and regulates the development, growth, pubertal maturation, and reproductive processes of the body. It is important for the production of sperm.



Slang term for steroids. Also used as a slang term for injecting equipment


Hormones that regulate growth, sexual development and reproductive function.

Gonadotropin-releasing hormone (GnRH)

Produced by the hypothalamus it stimulates the pituitary gland to produce luteinizing hormone and follicle stimulating hormone

Gauge or G (needles)

The gauge of a needle refers to the bore (the hole) running the length of a needle. In terms of injecting, steroids are a relatively dense substance and a larger gauge needle is required (21G, 23G). Note – with needles the smaller the number gauge the wider the hole on the needle


Over development of the gland tissue in male breasts, as a result of excess oestrogen produced in the body, (slang terms include bitch tits and man boobs). This is a primary side-effect of the use of anabolic steroids. For more information please see: Risks & Complications.


Half life

In simple terms, the half-life of a drug is how long it is active within the body. Short estered drugs like testosterone propionate, or most oral anabolic steroids, have a short half-life. Long estered drugs like testosterone  enanthate, have a much longer half-life. It is important to know the half-life of the drug you are using. For instance, you plan a cycle of 10 weeks, using 500mg of testosterone enanathate week. (Testosterone enanthate has a half-life of approximately 7 days).

This is how much testosterone enanthate is in your system:
(Figures are approximate as there are many factors that can influence the precise amount)

Day 1 = 500 mg
Day 7 = 270 mg

Then you inject again

Day 8 = 750mg

Each week, the amount in your system goes down as you approach your next injection; but when you inject again, there is still some left over from the previous injection. At the time of your last injection (day 71) there is nearly one gram (1,000 mg) of testosterone enanthate in your system. This means you may have much more anabolic steroid in your body than you thought. It also means it will be approximately 20 days from your last injection to the point where levels have dropped enough to start your post cycle therapy.

Many non-pharmaceutical anabolic steroids are variably dosed, which means you cannot be sure of how much you are injecting and therefore how much you have in your system. If possible, it is advisable to get blood tests to determine this before starting your post cycle therapy. Your local specialist needle exchange may be able to help with this.


A peptide hormone produced in the placenta during pregnancy. For further information please see Profiles of Commonly Used IPEDs.


Hepatic means “relating to the liver”. Toxicity refers to how much a substance can damage an organism. Therefore, Hepatotoxicity refers to how much a substance can cause damage to the liver. With IPEDs, this generally refers to the use of oral anabolic steroids.

High density lipoproteins (HDL)

A vehicle used by the body to carry cholesterol to the liver for excretion (see cholesterol)


The process of self-regulation whereby the body attempts to maintain a state of balance. The body will always try to return to this state and prolonged periods of disruption (such as a steroid cycles) can have a detrimental effect.


A chemical messenger substance secreted from a cell then carried via the blood stream to other cells to perform a specific task. Testosterone is a hormone that signals some cells to produce more protein (protein synthesis), this then leads to muscle growth.

Hormone Replacement Therapy (HRT)

The process of replacing hormones when the body is unable to produce enough naturally. In males this is typically achieved through the use of testosterone gels or patches, but monthly injections can also be used.


The Hypothalamic Pituitary Testicular Axis is the process by which natural testosterone production is managed. When the brain detects low levels of testosterone in the bloodstream, the hypothalamus then releases a hormone (GNRH) which signals the pituitary to release follicle stimulating hormone and luteinising hormone. These hormones then signal the testicles to produce testosterone and sperm. When exogenous testosterone is used, this process is effectively switched off. Post cycle therapy is designed to restart this process.


The enlargement of tissue (ie muscle) or an organ as a result of an increase in the number of cells.


The enlargement of tissue or an organ as a result of an increase in the size of the cells. This is what most bodybuilding training is designed to do. For further information see Training.


A condition where the body does not produce enough testosterone naturally. It can develop as a result of natural/genetic causes or it can start as a result of prolonged and heavy use of anabolic steroids. Severe cases require medical intervention.

Hypogonadotrophic Hypogonadism

A particular form of hypogonadism caused by a faulty hypothalamus or pituitary gland.


Abnormally low blood sugar levels that can lead to unconsciousness or can prove to be fatal in some cases. This is a serious issue for those who choose to use insulin. For further information see the Peptides section of Profiles of Commonly Used IPEDs.


Immune system

The body’s natural defence mechanism against illness or infection

Intramuscular (IM)

An injection into deep muscle tissue. Injectable steroids are administered intramuscularly; the needle needs to pass through the skin and fat layers, then into the muscle to deliver the substance.


An extremely powerful peptide hormone that regulates blood sugar levels as well as performing a range of important functions throughout the body. For more information please see the Peptides section of Profiles of Commonly Used IPEDs.

Insulin-like growth factor

This is a peptide hormone, released following stimulation by human growth hormone, that has an important mediating role in the action of human growth hormone. It helps to regulate cell growth and is an important part of the process the body undergoes during tissue growth.



Slang term for injectable steroids



Lactic acid

When the body is under high exertion, such as when weight training, the muscles can sometimes use up energy quicker than the body can deliver the oxygen needed to sustain energy levels, the body will then convert pyruvate(an organic acid) into lactate to allow glucose to be converted to energy. Lactic acid build up forces the body to slow down in order to prevent permanent muscle damage while more oxygen can be converted to energy. This is particularly common in long duration or high intensity exercise and can cause the body to respond more slowly, or prevent the muscle from lifting more weight until a suitable rest period has passed.

Left ventricular hypertrophy

A particular form of cardiomyopathy.

Leydig’s cells

The part of the testicles responsible for testosterone production.


Libido refers to a person’s desire for sexual activity, also called their “sex drive”. This is a complicated process that includes both biological and psychological components. The use of anabolic steroids can often increase libido dramatically; however there are some anabolic steroids that reduce libido (see individual drug profiles in Profiles of Commonly Used IPEDs). A reduction in libido is sometimes taken as a measure of low testosterone levels; however there may be many other reasons for a reduction in sexual desire, including stress, anxiety and poor physical health overall.


Lipoproteins are molecules made up of protein and fat that carry cholesterol. (See cholesterol)

Low density lipoproteins (LDL)

Low-density lipoprotein (LDL) refers to a class and range of lipoprotein particles that carry cholesterol around the body to cells (see cholesterol)


Lipids are a naturally occurring group of substances related to fats. They are used to store energy, in chemical signalling inside the body and are part of the structure of cell membranes.


The breakdown of lipids (fats). Refers to a process where the body breaks down fat into fatty acids to produce ketones which can be converted to energy.

Luteinizing hormone (LH)

A hormone produced by the pituitary gland that can stimulate production of testosterone in males and triggers ovulation in women. Post cycle therapy uses drugs that mimic or stimulate LH in order to signal the testes to start producing testosterone again.


A method of freeze drying substances to preserve them. Most peptide hormones (like human growth hormone and Melanotan), are supplied as freeze dried powders that need sterile or bacteriostatic water added to make them ready for injection.



A biochemical process that takes place in cells. Anabolism – uses energy to build cells, and Catabolism – breaking down of cells in order to retrieve energy. For further information see Diet.


The chemical by-product left behind when a substance is broken down by the body.


Also known as C17 Alpha Alkylated (or C17-aa, or just 17aa) – this refers to the manipulation of an oral anabolic steroid in order to allow it to survive passing through the liver. It is this characteristic of oral anabolic steroids that makes them hepatotoxic.

Myocardial infarction

The medical term for a heart attack.




The primary female sex hormone, this is another steroid hormone and, despite being a female hormone, plays a vital role in muscular development, the maintenance of libido, joint health and a range of other functions in men.

However, many unwanted side-effects of anabolic steroid use are due to elevated oestrogen levels caused by the body converting excess testosterone into oestradiol (a powerful form of oestrogen). Many bodybuilders use a range of drugs to combat this, but it is important not to overdo the process and remove too much oestrogen.


Refers to steroids that are in tablet form and are taken orally (swallowed). When taken orally steroids must first pass through the liver before they enter the system, this has an increased toxic effect on the liver compared to injectable steroids

Oil based steroids

Steroids mixed with oil to produce a soluble substance for injection. Oil and water based steroids should never be mixed


A condition that causes bones to become weaker and more brittle and therefore more likely to fracture (break).



Peptides are a particular type of hormone, separate from anabolic steroids.  For further information on specific peptides see Profiles of Commonly Used IPEDs.

Post Cycle Therapy (PCT)

Post cycle therapy is the process of restarting natural testosterone production following a cycle of anabolic steroids.


The point in training where effects start to diminish. This also refers to a point in the steroid cycle where the effects start to diminish.

Pituitary gland

A small gland about the size of a pea, situated at the front of the brain divided into anterior and posterior, it produces hormones and is part of the endocrine system


Progesterone is a female steroid hormone that is essential for the proper function of the reproductive system in women. It is also a precursor for both testosterone and oestrogen production; he body makes testosterone by first taking cholesterol and then changing it chemically into a series of different chemicals. One of these chemicals steps is progesterone. Progesterone is important in men to balance the effects of naturally produced oestrogen and can help with lowering insulin levels, asthma and osteoporosis.


A molecule that is used to build, maintain and replace tissues in your body. We get protein as a food source (macronutrient) but we also create proteins within the body. Proteins are essential in every biological action within the body. For more information, please see Diet and Training.



Roid Rage

This is a supposed psychological side-effect of anabolic steroid use characterised by unexplained and bursts of irritability or anger that are out of character. Whilst anabolic steroid use can increase aggression; it does not necessarily manifest in a negative way. It can be expressed through more positive means such as accomplishing more at work. There is little evidence to support the contention that anabolic steroid use leads to unusual aggressive behaviour, however it should be noted that there is some evidence to show some people are particularly sensitive to this possible side-effect.

If you feel you are getting particularly irritable whilst on-cycle, it is advised to discontinue or reduce your anabolic steroid use. Some people have reported that certain anabolic steroids always make them feel more irritable or angry and as such they no longer use those specific drugs.


Range of movement or motion, of a joint from flexion to extension


Rep maximum, refers to an individual’s capacity to lift certain weights – a 1 RM is the heaviest weight a person can lift once, a 10 RM is the weight a person can lift 10 times consecutively.



SERM is the acronym for Selective Estrogen Receptor Modulator, a class of drugs that are used to block the action of oestrogen in certain cells. The most commonly used SERM is tamoxifen citrate. For further information please see Profiles of Commonly Used IPEDs.

Sleep Apnoea

Sleep apnoea is a type of sleep disorder characterised by pauses in breathing or periods of very shallow breathing.


Taking two or more anabolic substances at the same time. (ie: Taking two or more steroids simultaneously)

Sterile Water

Water that has been treated to remove all bacterial contamination and then stored in a sealed container (usually a glass or plastic ampoule) until needed.


A class of hormones of which anabolic steroids are just one type. There are a range of different types of steroid all of which are similar chemically, but not in their action within the body. There are hundreds of different types of steroid, but only the anabolic steroids are used for physique and performance enhancing purposes.

Subcutaneous / Sub-cut / Sub Q

The method of injecting into the fatty tissue immediately below the skin surface between skin and the muscle.


The cooperative enhancement when one drug multiplies the effectiveness of another. It is common for IPED users to take more than one substance in the belief that the drugs will amplify or support the effect of each other.


T3, T4

A synthetic thyroid hormone tablet that may increase the synthesis of protein, carbohydrates, and fats.


A fibrous tissue that connects muscles to bone. The use of anabolic steroids can have a detrimental effect on tendon strength and it is not uncommon to see long term IPED users with torn muscles as a result. This is another reason for taking time off from anabolic steroid use as tendons take far longer to develop and strengthen than muscles do.

Testicular atrophy

A potential side effect of steroid use. When exogenous testosterone is used, the body stops producing it naturally. The longer this continues, the more likely it is that the testicles will start to atrophy (waste away) as they are not being used. The process of post cycle therapy is intended to overcome this by helping the testicles restart natural testosterone production. If testicular atrophy is particularly severe, it may require some considerable time or medical intervention in order to restart testosterone production. Taking sufficient time off and using shorter cycles can help prevent this becoming a more serious issue.


The primary male sex hormone required for; the development of male reproductive organs, sperm production, facial hair, muscular and growth. It also contributes to libido, bone strength and a range of other physical and psychological characteristics.


The thyroid gland is one of the largest endocrine glands and is found in the neck. The thyroid gland has a range of important functions including the regulation of energy use, the regulation of protein synthesis and the sensitivity of the body to various other hormones. Thyroid malfunction can lead to a range of quite serious medical conditions.




This term refers to the development of male sexual characteristics in females using anabolic steroids, these might include deepening of voice, facial hair, acne and loss of breast tissue. Unlike many of the side-effects in males; virilisation appears to be irreversible and consequently, female IPED users are advised to consider their drug use carefully. In particular, they are advised to avoid those compounds most commonly associated with virilising effects. For more information see Profiles of Commonly Used IPEDs.


Water based steroid

Some anabolic steroids are mixed with water to make the soluble for injection. Water and oil based steroids should never be mixed together. Examples of water bases steroids are stanozolol and testosterone suspension.


Slang term for Winstrol


Brand name for the anabolic steroid Stanozolol. Available in both oral and injectable preparations.  For more information please see Profiles of Commonly Used IPEDs.




Injecting carries several risks, both from the process and from the drugs themselves. It is important to be aware of these risks before attempting to inject any substance.

© 2019 Public Health Wales | Iechyd Cyhoeddus
Privacy Notice

Injecting carries several risks, both from the process and from the drugs themselves. It is important to be aware of these risks before attempting to inject any substance.

© 2018
Public Health Wales | Iechyd Cyhoeddus
Privacy Notice