Trenbolone is an

androgen An androgen (from Greek ''andr-'', the stem of the word meaning ) is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This includes ...

and

anabolic steroid Anabolic steroids, also known as anabolic-androgenic steroids (AAS), are a class of drugs that are structurally related to testosterone, the main male sex hormone, and produce effects by binding to the androgen receptor (AR). Anabolism, Anaboli ...

(AAS) of the

nandrolone Nandrolone, also known as 19-nortestosterone, is an endogenous androgen. It is also an anabolic steroid (AAS) which is medically used in the form of esters such as nandrolone decanoate (brand name Deca-Durabolin) and nandrolone phenylpropionate ...

group which itself was never marketed. Trenbolone ester

prodrug A prodrug is a pharmacologically inactive medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be ...

s, including

trenbolone acetate Trenbolone acetate, sold under brand names such as Finajet and Finaplix among others, is an androgen and anabolic steroid (AAS) medication used in veterinary medicine, specifically to increase the profitability of livestock by promoting muscle g ...

(brand names Finajet, Finaplix, others) and trenbolone hexahydrobenzylcarbonate (brand names Parabolan, Hexabolan), are or have been marketed for veterinary and clinical use. Trenbolone acetate is used in

veterinary medicine Veterinary medicine is the branch of medicine that deals with the prevention, management, medical diagnosis, diagnosis, and treatment of disease, disorder, and injury in non-human animals. The scope of veterinary medicine is wide, covering all a ...

livestock Livestock are the Domestication, domesticated animals that are raised in an Agriculture, agricultural setting to provide labour and produce diversified products for consumption such as meat, Egg as food, eggs, milk, fur, leather, and wool. The t ...

to increase muscle growth and

appetite Appetite is the desire to eat food items, usually due to hunger. Appealing foods can stimulate appetite even when hunger is absent, although appetite can be greatly reduced by satiety. Appetite exists in all higher life-forms, and serves to reg ...

, while trenbolone hexahydrobenzylcarbonate was formerly used clinically in humans but is now no longer marketed. In addition, although it is not approved for clinical or veterinary use, trenbolone enanthate is sometimes sold on the

black market A black market is a Secrecy, clandestine Market (economics), market or series of transactions that has some aspect of illegality, or is not compliant with an institutional set of rules. If the rule defines the set of goods and services who ...

under the name trenbolone. A vial of injectable Trenbolone

Uses

Veterinary

Trenbolone, as trenbolone acetate, improves muscle mass, feed efficiency, and mineral absorption in cattle.

Side effects

Sometimes human users may experience an event called "tren cough" shortly after or during an injection, where the user experiences a violent and extreme coughing fit, which can last for minutes and in some cases even longer. "Tren cough", despite its name, is not exclusive to trenbolone. It can occur when injecting any oil-steroid solutions, if the solution accidentally is injected intravenously. When the oil-steroid solution gets into the bloodstream, the steroid oil solution travels into the lungs, therefore causing a coughing fit. There exist several theories on why this phenomenon happens. It is possible that the androgenic effect from steroids activates a variety of lipid-like active compounds which are called

prostaglandins Prostaglandins (PG) are a group of physiologically active lipid compounds called eicosanoids that have diverse hormone-like effects in animals. Prostaglandins have been found in almost every tissue in humans and other animals. They are derive ...

. Many of these prostaglandins are inflammatory and vasoconstrictive. Prostaglandins are signalled through two varying pathways cyclooxygenase (COX) (Also known as: prostaglandin-endoperoxide synthase) and lipoxygenases (LOX) (also known as: EC 1.13.11.34, EC 1.13.11.33, etc.). The bradykinin peptide is well known to promote a cough reaction associated with

ACE inhibitor Angiotensin-converting-enzyme inhibitors (ACE inhibitors) are a class of medication used primarily for the treatment of high blood pressure and heart failure. This class of medicine works by causing relaxation of blood vessels as well as a decr ...

medications prescribed for

hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

Pharmacology

Pharmacodynamics

Trenbolone has both

anabolic Anabolism () is the set of metabolic pathways that construct macromolecules like DNA or RNA from smaller units. These reactions require energy, known also as an endergonic process. Anabolism is the building-up aspect of metabolism, whereas catab ...

and androgenic effects. Once

metabolized Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the co ...

, trenbolone esters have the effect of increasing

ammonium Ammonium is a modified form of ammonia that has an extra hydrogen atom. It is a positively charged (cationic) polyatomic ion, molecular ion with the chemical formula or . It is formed by the protonation, addition of a proton (a hydrogen nucleu ...

ion uptake by muscles, leading to an increase in the rate of

protein synthesis Protein biosynthesis, or protein synthesis, is a core biological process, occurring inside cells, balancing the loss of cellular proteins (via degradation or export) through the production of new proteins. Proteins perform a number of critica ...

. It may also have the secondary effects of stimulating appetite and decreasing the rate of

catabolism Catabolism () is the set of metabolic pathways that breaks down molecules into smaller units that are either oxidized to release energy or used in other anabolic reactions. Catabolism breaks down large molecules (such as polysaccharides, lipid ...

, as all

anabolic steroids Anabolic steroids, also known as anabolic-androgenic steroids (AAS), are a class of drugs that are structurally related to testosterone, the main male sex hormone, and produce effects by binding to the androgen receptor (AR). Anabolic steroids ...

are believed to; however, catabolism likely increases significantly once the steroid is no longer taken. At least one study in rats has shown trenbolone to cause gene expression of the

androgen receptor The androgen receptor (AR), also known as NR3C4 (nuclear receptor subfamily 3, group C, member 4), is a type of nuclear receptor that is activated by binding any of the androgenic hormones, including testosterone and dihydrotestosterone, in th ...

(AR) at least as potent as

dihydrotestosterone Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone primarily involved in the growth and repair of the prostate and the penis, as well as the production o ...

(DHT). This evidence tends to indicate trenbolone can cause an increase in male

secondary sex characteristic A secondary sex characteristic is a physical characteristic of an organism that is related to or derived from its sex, but not directly part of its reproductive system. In humans, these characteristics typically start to appear during pubert ...

s without the need to convert to a more potent androgen in the body. Studies on metabolism are mixed, with some studies showing that it is metabolized by

aromatase Aromatase (), also called estrogen synthetase or estrogen synthase, is an enzyme responsible for a key step in the biosynthesis of estrogens. It is CYP19A1, a member of the cytochrome P450 superfamily, which are monooxygenases that catalyze man ...

into

estrogen Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three ...

ic compounds, or by 5α-reductase into 5α-reduced androgenic compounds. The potency of Trenbolone is not known, although it's often falsely believed to be five times higher than

testosterone Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting se ...

. This is based on a book by William Llewellyn but has not been definitively proven. Trenbolone was never approved for human use, and therefore limited data on the subject exists. The relevant studies are usually done in rats, which makes the 500/100 potency number inaccurate. Rats respond differently and are less sensitive to androgens. While some literature report a 5 fold higher potency, two other scientific reviews report a 3 fold higher potency. Trenbolone also binds with high

affinity Affinity may refer to: Commerce, finance and law * Affinity (law), kinship by marriage * Affinity analysis, a market research and business management technique * Affinity Credit Union, a Saskatchewan-based credit union * Affinity Equity Pa ...

to the

progesterone receptor The progesterone receptor (PR), also known as NR3C3 or nuclear receptor subfamily 3, group C, member 3, is a protein found inside cells. It is activated by the steroid hormone progesterone. In humans, PR is encoded by a single ''PGR'' gene resi ...

, and binds to the

glucocorticoid receptor The glucocorticoid receptor (GR or GCR) also known by its gene name ''NR3C1'' ( nuclear receptor subfamily 3, group C, member 1) is the steroid receptor for glucocorticoids such as cortisol. The GR is expressed in almost every cell in the bod ...

as well.

Pharmacokinetics

To prolong its

elimination half-life Biological half-life (elimination half-life, pharmacological half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the blood plasma. ...

, trenbolone is administered as a

as an

ester In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...

conjugate such as

, trenbolone enanthate, or trenbolone hexahydrobenzylcarbonate. Plasma

lipase In biochemistry, lipase ( ) refers to a class of enzymes that catalyzes the hydrolysis of fats. Some lipases display broad substrate scope including esters of cholesterol, phospholipids, and of lipid-soluble vitamins and sphingomyelinases; howe ...

s then cleave the ester group in the bloodstream leaving free trenbolone. Trenbolone and 17-epitrenbolone are both excreted in urine as conjugates that can be hydrolyzed with beta-glucuronidase. This implies that trenbolone leaves the body as beta-

glucuronide A glucuronide, also known as glucuronoside, is any substance produced by linking glucuronic acid to another substance via a glycosidic bond. The glucuronides belong to the glycosides. Glucuronidation, the conversion of chemical compounds to glucu ...

s or

sulfate The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ...

Chemistry

Trenbolone, also known as 19-nor-δ^9,11-testosterone or as estra-4,9,11-trien-17β-ol-3-one, is a

synthetic Synthetic may refer to: Science * Synthetic biology * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic elements, chemical elements that are not naturally found on Earth and therefore have to be created in ...

estrane Estrane is a C18 steroid derivative, with a gonane core. ''Estrenes'' are estrane derivatives that contain a double bond, with an example being nandrolone. ''Estratrienes'' (estrins) are estrane derivatives that contain three double bonds, for i ...

steroid A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes t ...

and a

derivative In mathematics, the derivative is a fundamental tool that quantifies the sensitivity to change of a function's output with respect to its input. The derivative of a function of a single variable at a chosen input value, when it exists, is t ...

(19-nortestosterone). It is specifically nandrolone with two additional

double bond In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...

s in the steroid nucleus. Trenbolone esters, which have an

at the C17β position, include

, trenbolone enanthate, trenbolone hexahydrobenzylcarbonate, and trenbolone undecanoate.

History

Trenbolone was first synthesized in 1963.

Society and culture

Generic names

''Trenbolone'' is the generic name of the drug and its and . It has also been referred to as ''trienolone'' or ''trienbolone'' or tren.

Legal status

Some

bodybuilder Bodybuilding is the practice of progressive resistance exercise to build, control, and develop one's muscles via hypertrophy. An individual who engages in this activity is referred to as a bodybuilder. It is primarily undertaken for aesthetic ...

s and

athlete An athlete is most commonly a person who competes in one or more sports involving physical strength, speed, power, or endurance. Sometimes, the word "athlete" is used to refer specifically to sport of athletics competitors, i.e. including track ...

s use trenbolone hexahydrobenzylcarbonate and other esters (acetate, enanthate) for their muscle-building and otherwise performance-enhancing effects. Such use is illegal in the United States and several European and Asian countries. The DEA classifies trenbolone and its esters as

Schedule III controlled substance The Controlled Substances Act (CSA) is the statute establishing federal U.S. drug policy under which the manufacture, importation, possession, use, and distribution of certain substances is regulated. It was passed by the 91st United States ...

s under the

Controlled Substances Act The Controlled Substances Act (CSA) is the statute establishing federal government of the United States, federal drug policy of the United States, U.S. drug policy under which the manufacture, importation, possession, use, and distribution of ...

. Trenbolone is classified as a Schedule 4 drug in

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

and a class C drug with no penalty for personal use or possession in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

. Use or possession of steroids without a prescription is a crime in

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

Doping in sports

There are known cases of doping in sports with trenbolone esters by

professional A professional is a member of a profession or any person who work (human activity), works in a specified professional activity. The term also describes the standards of education and training that prepare members of the profession with the partic ...

Environmental persistence

Early studies suggested that the metabolites of trenbolone acetate would degrade through phototransformation. However, a 2013 paper found that the endocrine-disrupting metabolites were able to reform at night, resulting in a diurnal cycling of the compounds. The environmental persistence of the steroid metabolites results in the contamination of water supplies and the disruption of aquatic reproductive processes. Due to its nocturnal reformation, researchers have referred to trenbolone as the "vampire steroid".