Androgen ester
Testosterone undecanoate, an ester of testosterone and one of the most widely used androgen esters.
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-resistant prohormones of themselves, improving oral bioavailability, increasing lipophilicity, and extending the elimination half-life (which necessitates less frequent administration). In addition, with intramuscular injection, AAS esters are absorbed more slowly into the body, further improving the elimination half-life. Aside from differences in pharmacokinetics (e.g., duration), these esters essentially have the same effects as the parent drugs.[1] They are used in androgen replacement therapy (ART), among other indications. Examples of androgen esters include testosterone esters such as testosterone cypionate, testosterone enanthate, testosterone propionate, and testosterone undecanoate and nandrolone esters such as nandrolone decanoate and nandrolone phenylpropionate.
| Androgen | Structure | Ester | Rel. MWb | Rel. Tc | Durationd | ||||
|---|---|---|---|---|---|---|---|---|---|
| Position | Moiety | Type | Lengtha | Rank | Group | ||||
| Testosterone |  | – | – | – | – | 1.00 | 1.00 | 6 | Short |
| Testosterone propionate |  | C17β | Propanoic acid | Straight-chain fatty acid | 3 | 1.19 | 0.84 | 5 | Short |
| Testosterone cypionate |  | C17β | Cyclopentylpropanoic acid | Aromatic fatty acid | – (~6) | 1.43 | 0.70 | 4 | Moderate |
| Testosterone enanthate |  | C17β | Heptanoic acid | Straight-chain fatty acid | 7 | 1.39 | 0.72 | 3 | Moderate |
| Testosterone undecanoate |  | C17β | Undecanoic acid | Straight-chain fatty acid | 11 | 1.58 | 0.63 | 2 | Long |
Testosterone buciclatee |  | C17β | Bucyclic acidf | Aromatic carboxylic acid | – (~9) | 1.58 | 0.63 | 1 | Long |
Footnotes: a = Length of ester in carbon atoms for straight-chain fatty acids or approximate length of ester in carbon atoms for aromatic fatty acids. b = Relative molecular weight. c = Relative testosterone content by weight (i.e., relative androgenic potency). d = Duration by intramuscular or subcutaneous injection. e = Never marketed. f = Bucyclic acid = trans-4-Butylcyclohexane-1-carboxylic acid. Sources: See individual articles. | |||||||||
| Anabolic steroid | Structure | Ester | Rel. MWb | Rel. AASc | Durationd | ||||
|---|---|---|---|---|---|---|---|---|---|
| Position | Moiety | Type | Lengtha | ||||||
| Boldenone undecylenate |  | C17β | Undecylenic acid | Straight-chain fatty acid | 11 | 1.58 | 0.63 | Long | |
| Drostanolone propionate |  | C17β | Propanoic acid | Straight-chain fatty acid | 3 | 1.18 | 0.84 | Short | |
| Metenolone acetate |  | C17β | Ethanoic acid | Straight-chain fatty acid | 2 | 1.14 | 0.88 | Short | |
| Metenolone enanthate |  | C17β | Heptanoic acid | Straight-chain fatty acid | 7 | 1.37 | 0.73 | Long | |
| Nandrolone decanoate |  | C17β | Decanoic acid | Straight-chain fatty acid | 10 | 1.56 | 0.64 | Long | |
| Nandrolone phenylpropionate |  | C17β | Phenylpropanoic acid | Aromatic fatty acid | – (~6–7) | 1.48 | 0.67 | Long | |
| Trenbolone acetate |  | C17β | Ethanoic acid | Straight-chain fatty acid | 2 | 1.16 | 0.87 | Short | |
Trenbolone enanthatee |  | C17β | Heptanoic acid | Straight-chain fatty acid | 7 | 1.41 | 0.71 | Long | |
Footnotes: a = Length of ester in carbon atoms for straight-chain fatty acids or approximate length of ester in carbon atoms for aromatic fatty acids. b = Relative molecular weight compared to unesterified parent steroid. c = Relative anabolic steroid content by weight (i.e., relative androgenic potency) compared to unesterified parent steroid. d = Duration by intramuscular or subcutaneous injection. e = Never marketed. Sources: See individual articles. | |||||||||
See also
- List of androgen esters
- List of androgens/anabolic steroids
- Steroid ester
- Estrogen ester
- Progestogen ester
References
^ Richard Lawrence Miller (2002). The Encyclopedia of Addictive Drugs. Greenwood Publishing Group. pp. 416–. ISBN 978-0-313-31807-8..mw-parser-output cite.citationfont-style:inherit.mw-parser-output .citation qquotes:"""""""'""'".mw-parser-output .citation .cs1-lock-free abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .citation .cs1-lock-limited a,.mw-parser-output .citation .cs1-lock-registration abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .citation .cs1-lock-subscription abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registrationcolor:#555.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration spanborder-bottom:1px dotted;cursor:help.mw-parser-output .cs1-ws-icon abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Wikisource-logo.svg/12px-Wikisource-logo.svg.png")no-repeat;background-position:right .1em center.mw-parser-output code.cs1-codecolor:inherit;background:inherit;border:inherit;padding:inherit.mw-parser-output .cs1-hidden-errordisplay:none;font-size:100%.mw-parser-output .cs1-visible-errorfont-size:100%.mw-parser-output .cs1-maintdisplay:none;color:#33aa33;margin-left:0.3em.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-formatfont-size:95%.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-leftpadding-left:0.2em.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-rightpadding-right:0.2em
Further reading
Vermeulen A (1975). "Longacting steroid preparations". Acta Clin Belg. 30 (1): 48–55. doi:10.1080/17843286.1975.11716973. PMID 1231448.
