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

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

(AAS) medication 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 horm ...

for transgender men. It is taken by mouth or given by

injection into muscle 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 have l ...

. Side effects 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 showin ...

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 ...

like acne, increased hair growth, voice changes,

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 bl ...

, 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 drug ...

of testosterone, the

biological ligand In biochemistry and pharmacology, a ligand is a substance that forms a complex with a biomolecule to serve a biological purpose. The etymology stems from ''ligare'', which means 'to bind'. In protein-ligand binding, the ligand is usually a mole ...

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) and hence is an androgen and anabolic steroid. It has strong androgenic effects and moderate anabolic 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

of testosterone 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 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 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. 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 have ...

, it is administered at a dosage of 1,000 mg once every 12 weeks. Conversely, oral testosterone undecanoate must be taken two or three times a day with food.

Side effects

Side effects of testosterone undecanoate include virilization among others.

Anaphylaxis

The Reandron 1000 formulation (Nebido in the United States) contains 1,000 mg of testosterone undecanoate suspended in castor oil with benzyl benzoate for solubilization and as a preservative, and is administered by

. As an excipient in Reandron 1000, benzyl benzoate has been reported as a cause of anaphylaxis (a serious life-threatening allergic reaction) in a case in

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

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

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 (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 ago ...

of the

(AR).

Pharmacokinetics

Testosterone undecanoate has a very long elimination half-life 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 castor oil. These values are substantially longer than those of testosterone enanthate (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 o ...

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 a ...

and a derivative of testosterone. It is an androgen ester; specifically, it is the C17β undecylate (undecanoate) ester of testosterone. A related testosterone ester with a similarly very long duration is testosterone buciclate.

History

In the late 1970s, testosterone undecanoate was introduced for oral use in Europe, 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 most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

for several years. Intramuscular testosterone undecanoate was not introduced in Europe and the United States 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 controlled substance in the United States 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 ...

and a schedule IV controlled substance in Canada under the Controlled Drugs and Substances Act. In March 2019, the US Food and Drug Administration (FDA) approved testosterone undecanoate (Jatenzo), an oral testosterone capsule to treat men with certain forms of hypogonadism. 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 Phase II, Phase 2 or Phase Two may refer to: Media * Marvel Cinematic Universe: Phase Two, six American superhero films from 2013–2015 * ''Star Trek: Phase II'', an unrealized television series based on the characters of Gene Roddenberry's ''S ...

clinical trial testing intramuscular testosterone undecanoate for the treatment of non-alcoholic steatohepatitis (NASH) was initiated in the United Kingdom. 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