An androgen or anabolic steroid ester is an

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 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 ...

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 t ...

(AAS) such as the natural

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 characteris ...

dihydrotestosterone Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone. The enzyme 5α-reductase catalyzes the formation of DHT from testosterone in certain tissues incl ...

(DHT) or the synthetic

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

(19-nortestosterone). Esterification renders AAS into

metabolism Metabolism (, from el, μεταβολή ''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 c ...

-resistant

prohormone A prohormone is a committed precursor of a hormone consisting of peptide hormones synthesized together that has a minimal hormonal effect by itself because of its expression-suppressing structure, often created by protein folding and binding addit ...

s of themselves, improving

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 ora ...

bioavailability In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. ...

, increasing

lipophilicity Lipophilicity (from Greek λίπος "fat" and φίλος "friendly"), refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. Such non-polar solvents are themselves lipo ...

, and extending the

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 bl ...

(which necessitates less frequent administration). In addition, with

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 ...

, AAS esters are absorbed more slowly into the body, further improving the elimination half-life. Aside from differences in

pharmacokinetics Pharmacokinetics (from Ancient Greek ''pharmakon'' "drug" and ''kinetikos'' "moving, putting in motion"; see chemical kinetics), sometimes abbreviated as PK, is a branch of pharmacology dedicated to determining the fate of substances administered ...

(e.g., duration), these esters essentially have the same effects as the parent drugs. They are used in

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 exogenousl ...

(ART), among other indications. Examples of androgen esters include

testosterone ester This is a list of androgen esters, including esters (as well as ethers) of natural androgens like testosterone and dihydrotestosterone (DHT) and synthetic anabolic–androgenic steroids (AAS) like nandrolone (19-nortestosterone). Esters of na ...

s such as testosterone cypionate, testosterone enanthate,

testosterone propionate Testosterone propionate, sold under the brand name Testoviron among others, is an androgen and anabolic steroid (AAS) medication which is used mainly in the treatment of low testosterone levels in men. It has also been used to treat breast cance ...

, and

testosterone undecanoate Testosterone undecanoate, sold under the brand names Andriol and Aveed among others, is an androgen and anabolic steroid (AAS) medication that is used mainly in the treatment of low testosterone levels in men, including hormone therapy for tr ...

and

nandrolone ester This is a list of androgen esters, including esters (as well as ethers) of natural androgens like testosterone and dihydrotestosterone (DHT) and synthetic anabolic–androgenic steroids (AAS) like nandrolone (19-nortestosterone). Esters of na ...

s such as

nandrolone decanoate Nandrolone decanoate, sold under the brand name Deca-Durabolin among others, is an androgen and anabolic steroid (AAS) medication which is used primarily in the treatment of anemias and wasting syndromes, as well as osteoporosis in menopausal wom ...

and

nandrolone phenylpropionate Nandrolone phenylpropionate (NPP), or nandrolone phenpropionate, sold under the brand name Durabolin among others, is an androgen and anabolic steroid (AAS) medication which has been used primarily in the treatment of breast cancer and osteoporos ...

See also

References

Further reading