Testosterone undecanoate, sold under the brand names Andriol and Aveed among others, is an

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

and

anabolic steroid Anabolic steroids, also known more properly as anabolic–androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone as well as synthetic androgens that are structurally related and have similar effects ...

(AAS)

medication A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the medical field and ...

that is used mainly in the treatment of low testosterone levels in men, including

hormone therapy Hormone therapy or hormonal therapy is the use of hormones in medical treatment. Treatment with hormone antagonists may also be referred to as hormonal therapy or antihormone therapy. The most general classes of hormone therapy are oncologic ho ...

for

transgender men A trans man is a man who was assigned female at birth. The label of transgender man is not always interchangeable with that of transsexual man, although the two labels are often used in this way. ''Transgender'' is an umbrella term that incl ...

. It is taken

by mouth Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are i ...

or given by injection into muscle.

Side effect In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...

s of testosterone undecanoate include

symptom Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showi ...

s of

masculinization Virilization or masculinization is the biological development of adult male characteristics in young males or females. Most of the changes of virilization are produced by androgens. Virilization is most commonly used in three medical and biology ...

acne Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and ...

, increased hair growth,

voice changes ' A voice change or voice mutation, sometimes referred to as a voice break or voice crack, commonly refers to the deepening of the voice of men as they reach puberty. Before puberty, both sexes have roughly similar vocal pitch, but during puberty ...

hypertension Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high b ...

, elevated liver enzymes, hypertriglyceridemia, and increased sexual desire. The drug is a

prodrug A prodrug is a 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 used to improve how the dru ...

of testosterone, the biological ligand 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 ...

(AR) and hence is an androgen and anabolic steroid. It has strong

ic effects and moderate

anabolic Anabolism () is the set of metabolic pathways that construct molecules from smaller units. These reactions require energy, known also as an endergonic process. Anabolism is the building-up aspect of metabolism, whereas catabolism is the breakin ...

effects, which make it useful for producing masculinization and suitable for

androgen replacement therapy Androgen replacement therapy (ART), often referred to as testosterone replacement therapy (TRT) or hormone replacement therapy (HRT), is a form of hormone therapy in which androgens, often testosterone, are supplemented or replaced exogenously ...

. Testosterone undecanoate is a testosterone ester and a

testosterone Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristi ...

in the body. Because of this, it is considered to be a natural and bioidentical form of testosterone. Testosterone undecanoate was introduced in China for use by injection and in the European Union for use by mouth in the 1970s. It became available for use by injection in the European Union in the early to mid 2000s and in the United States in 2014. Formulations for use by mouth are approved in the United States. Along with

testosterone enanthate Testosterone enanthate, sold under the brand names Delatestryl and Xyosted among others, is an androgen and anabolic steroid (AAS) medication which is used mainly in the treatment of low testosterone levels in men. It is also used in hormone th ...

, testosterone cypionate, and testosterone propionate, testosterone undecanoate is one of the most widely used testosterone esters. However, it has advantages over other testosterone esters in that it can be taken by mouth and in that it has a far longer duration when given by injection. In addition to its medical use, testosterone undecanoate is used to improve physique and performance. The drug is a

controlled substance A controlled substance is generally a drug or chemical whose manufacture, possession and use is regulated by a government, such as illicitly used drugs or prescription medications that are designated by law. Some treaties, notably the Single ...

in many countries and so non-medical use is generally illicit.

Medical dosage

Testosterone undecanoate is used in

. It is specifically approved only for the treatment of

hypogonadism Hypogonadism means diminished functional activity of the gonads—the testes or the ovaries—that may result in diminished production of sex hormones. Low androgen (e.g., testosterone) levels are referred to as hypoandrogenism and low estroge ...

. As an

intramuscular injection Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles hav ...

, it is administered at a dosage of 1,000 mg once every 12 weeks. Conversely,

oral The word oral may refer to: Relating to the mouth * Relating to the mouth, the first portion of the alimentary canal that primarily receives food and liquid ** Oral administration of medicines ** Oral examination (also known as an oral exam or or ...

testosterone undecanoate must be taken two or three times a day with food.

Side effects

s of testosterone undecanoate include

virilization Virilization or masculinization is the biological development of adult male characteristics in young males or females. Most of the changes of virilization are produced by androgens. Virilization is most commonly used in three medical and biology ...

among others.

Anaphylaxis

The Reandron 1000 formulation (Nebido in the United States) contains 1,000 mg of testosterone undecanoate suspended in

castor oil Castor oil is a vegetable oil pressed from castor beans. It is a colourless or pale yellow liquid with a distinct taste and odor. Its boiling point is and its density is 0.961 g/cm3. It includes a mixture of triglycerides in which about ...

with

benzyl benzoate Benzyl benzoate is an organic compound which is used as a medication and insect repellent. As a medication it is used to treat scabies and lice. For scabies either permethrin or malathion is typically preferred. It is applied to the skin as a ...

for solubilization and as a

preservative A preservative is a substance or a chemical that is added to products such as food products, beverages, pharmaceutical drugs, paints, biological samples, cosmetics, wood, and many other products to prevent decomposition by microbial growth or b ...

, and is administered by

. As an

excipient An excipient is a substance formulated alongside the active ingredient of a medication, included for the purpose of long-term stabilization, bulking up solid formulations that contain potent active ingredients in small amounts (thus often referred ...

in Reandron 1000, benzyl benzoate has been reported as a cause of

anaphylaxis Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the follo ...

(a serious life-threatening

allergic reaction Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derm ...

) in a case in

Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...

Bayer Bayer AG (, commonly pronounced ; ) is a German multinational pharmaceutical and biotechnology company and one of the largest pharmaceutical companies in the world. Headquartered in Leverkusen, Bayer's areas of business include pharmaceutic ...

includes this report in information for health professionals and recommends that physicians "should be aware of the potential for serious allergic reactions" to preparations of this type. In Australia, reports to the Adverse Drug Reactions Advisory Committee (ADRAC), which evaluates reports of adverse drug reactions for the

Therapeutic Goods Administration The Therapeutic Goods Administration (TGA) is the medicine and therapeutic regulatory agency of the Australian Government. As part of the Department of Health and Aged Care, the TGA regulates the quality, supply and advertising of medicines, p ...

(TGA), show several reports of allergic reactions since the anaphylaxis case from 2011.

Pharmacology

Pharmacodynamics

Testosterone undecanoate is a

of testosterone and is an androgen and

anabolic–androgenic steroid Anabolic steroids, also known more properly as anabolic–androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone as well as synthetic androgens that are structurally related and have similar effects t ...

(AAS). That is, it is an

agonist An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ag ...

of the

(AR).

Pharmacokinetics

Testosterone undecanoate has a very long

elimination half-life Biological half-life (also known as elimination half-life, pharmacologic 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 b ...

and mean residence time when given as a depot

. Its elimination half-life is 20.9 days and its mean residence time is 34.9 days in tea seed oil, while its elimination half-life is 33.9 days and its mean residence time is 36.0 days in

. These values are substantially longer than those of

(which, in castor oil, has values of 4.5 days and 8.5 days, respectively). Testosterone undecanoate is administered via intramuscular injection once every three months or so.

Chemistry

Testosterone undecanoate, or testosterone 17β-undecanoate, is a

synthetic Synthetic things are composed of multiple parts, often with the implication that they are artificial. In particular, 'synthetic' may refer to: Science * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic ...

androstane

steroid A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and ...

and a

derivative In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. ...

. It is an

androgen ester An androgen or anabolic steroid ester is an ester of an androgen/anabolic steroid (AAS) such as the natural testosterone or dihydrotestosterone (DHT) or the synthetic nandrolone (19-nortestosterone). Esterification renders AAS into metabolism-re ...

; specifically, it is the C17β undecylate (undecanoate)

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ...

of testosterone. A related testosterone ester with a similarly very long duration is

testosterone buciclate Testosterone buciclate (developmental code names 20 Aet-1, CDB-1781) is a synthetic, injected anabolic–androgenic steroid (AAS) which was never marketed. It was developed in collaboration by the Contraceptive Development Branch (CDB) of the N ...

History

In the late 1970s, testosterone undecanoate was introduced for oral use in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

, although intramuscular testosterone undecanoate had already been in use in

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...

for several years. Intramuscular testosterone undecanoate was not introduced in Europe and the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

until much later, in the early to mid 2000s and 2014, respectively. Testosterone undecanoate was approved in the United States after three previous rejections due to safety concerns.

Society and culture

Generic names

''Testosterone undecanoate'' is the generic name of the drug and its and . It is also referred to as ''testosterone undecylate''.

Brand names

Testosterone undecanoate is or has been marketed under a variety of brand names, including Andriol, Androxon, Aveed, Cernos Depot, Jatenzo, Nebido, Nebido-R, Panteston, Reandron 1000, Restandol, Undecanoate 250, and Undestor.

Availability

Intramuscular testosterone undecanoate is available in the United States, Canada, Europe, and elsewhere in the world. It is approved in over 100 countries worldwide. Oral testosterone undecanoate is available in Canada, Europe, Mexico, Asia, and in the United States. Intramuscular testosterone undecanoate is marketed most commonly as Nebido in Canada and Europe and as Aveed in the United States while oral testosterone undecanoate is marketed most commonly as Andriol.

Legal status

Testosterone undecanoate, along with other AAS, is a schedule III

in the

under the

Controlled Substances Act 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 ...

and a schedule IV controlled substance in

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by to ...

under the

Controlled Drugs and Substances Act The ''Controlled Drugs and Substances Act'' (french: Loi réglementant certaines drogues et autres substances) (the ''Act'') is Canada's federal drug control statute. Passed in 1996 under Prime Minister Jean Chrétien's government, it repeal ...

. In March 2019, the US

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...

(FDA) approved testosterone undecanoate (Jatenzo), an oral testosterone capsule to treat men with certain forms of

. These men have low testosterone levels due to specific medical conditions, such as genetic disorders like Klinefelter syndrome or tumors that have damaged the pituitary gland. The FDA granted the approval of Jatenzo to Clarus Therapeutics. In March 2022, testosterone undecanoate (Tlando) was approved for medical use in the United States.

Research

Non-alcoholic steatohepatitis

In 2013, a phase II

clinical trial Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, diet ...

testing intramuscular testosterone undecanoate for the treatment of

non-alcoholic steatohepatitis Non-alcoholic fatty liver disease (NAFLD), also known as metabolic (dysfunction) associated fatty liver disease (MAFLD), is excessive fat build-up in the liver without another clear cause such as alcohol use. There are two types; non-alcoholic ...

(NASH) was initiated 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 Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and ...

. In the United States in 2018, Lipocine Inc. began investigating the potential of using an oral testosterone undecanoate formulation, known as LPCN-1144, in patients with NASH.

References

External links

* {{Portal bar , Medicine Androgens and anabolic steroids Androstanes Bayer brands Contraception for males Ketones Testosterone esters Undecanoate esters