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.

Parenteral durations of androgens/anabolic steroids
Medication Form Major brand names Duration
Testosterone Aqueous suspension Andronaq, Sterotate, Virosterone 2–3 days
Testosterone propionate Oil solution Androteston, Perandren, Testoviron 3–4 days
Testosterone phenylpropionate Oil solution Testolent 8 days
Testosterone isobutyrate Aqueous suspension Agovirin Depot, Perandren M 14 days
Mixed testosterone estersa Oil solution Triolandren 10–20 days
Mixed testosterone estersb Oil solution Testosid Depot 14–20 days
Testosterone enanthate Oil solution Delatestryl 14–28 days
Testosterone cypionate Oil solution Depovirin 14–28 days
Mixed testosterone estersc Oil solution Sustanon 250 28 days
Testosterone undecanoate Oil solution Aveed, Nebido 100 days
Testosterone buciclated Aqueous suspension 20 Aet-1, CDB-1781e 90–120 days
Nandrolone phenylpropionate Oil solution Durabolin 10 days
Nandrolone decanoate Oil solution Deca Durabolin 21–28 days
Methandriol Aqueous suspension Notandron, Protandren 8 days
Methandriol bisenanthoyl acetate Oil solution Notandron Depot 16 days
Metenolone acetate Oil solution Primobolan 3 days
Metenolone enanthate Oil solution Primobolan Depot 14 days
Note: All are via i.m. injection. Footnotes: a = TP, TV, and TUe. b = TP and TKL. c = TP, TPP, TiCa, and TD. d = Studied but never marketed. e = Developmental code names. Sources: See template.
Pharmacokinetics of testosterone esters
Testosterone ester Form Route Tmax t1/2 MRT
Testosterone undecanoate Oil-filled capsules Oral ? 1.6 hours 3.7 hours
Testosterone propionate Oil solution Intramuscular injection ? 0.8 days 1.5 days
Testosterone enanthate Castor oil solution Intramuscular injection 10 days 4.5 days 8.5 days
Testosterone undecanoate Tea seed oil solution Intramuscular injection 13.0 days 20.9 days 34.9 days
Testosterone undecanoate Castor oil solution Intramuscular injection 11.4 days 33.9 days 36.0 days
Testosterone buciclatea Aqueous suspension Intramuscular injection 25.8 days 29.5 days 60.0 days
Notes: Testosterone cypionate has similar pharmacokinetics to TE. Footnotes: a = Never marketed. Sources: See template.
Structural properties of major testosterone esters
Androgen Structure Ester Relative
mol. weight
Relative
T contentb
Durationc
Position Moiety Type Lengtha Rank Group
Testosterone Testosteron.svg 1.00 1.00 11 Short
Testosterone propionate Testosterone propionate.svg C17β Propanoic acid Straight-chain fatty acid 3 1.19 0.84 10 Short
Testosterone isobutyrate Testosterone isobutyrate.svg C17β Isobutyric acid Aromatic fatty acid – (~3) 1.24 0.80 9 Moderate
Testosterone cypionate Testosterone cypionate.svg C17β Cyclopentylpropanoic acid Aromatic fatty acid – (~6) 1.43 0.70 8 Moderate
Testosterone phenylpropionate Testosterone phenpropionate.svg C17β Phenylpropanoic acid Aromatic fatty acid – (~6) 1.46 0.69 7 Moderate
Testosterone isocaproate Testosterone isocaproate.svg C17β Isohexanoic acid Branched-chain fatty acid – (~5) 1.34 0.75 6 Moderate
Testosterone caproate Testosterone caproate.svg C17β Hexanoic acid Straight-chain fatty acid 6 1.35 0.75 5 Moderate
Testosterone enanthate Testosterone enanthate.svg C17β Heptanoic acid Straight-chain fatty acid 7 1.39 0.72 4 Moderate
Testosterone decanoate Testosterone decanoate.svg C17β Decanoic acid Straight-chain fatty acid 10 1.53 0.65 3 Long
Testosterone undecanoate Testosterone undecanoate.svg C17β Undecanoic acid Straight-chain fatty acid 11 1.58 0.63 2 Long
Testosterone buciclated Testosteronebuciclate structure.png C17β Bucyclic acide 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 testosterone content by weight (i.e., relative androgenic/anabolic potency). c = Duration by intramuscular or subcutaneous injection in oil solution (except TiB and TB, which are in aqueous suspension). d = Never marketed. e = Bucyclic acid = trans-4-Butylcyclohexane-1-carboxylic acid. Sources: See individual articles.
Structural properties of major anabolic steroid esters
Anabolic steroid Structure Ester Relative
mol. weight
Relative
AAS contentb
Durationc
Position Moiety Type Lengtha
Boldenone undecylenate
Boldenone undecylenate.svg
C17β Undecylenic acid Straight-chain fatty acid 11 1.58 0.63 Long
Drostanolone propionate
Drostanolone propionate.svg
C17β Propanoic acid Straight-chain fatty acid 3 1.18 0.84 Short
Metenolone acetate
Metenolone acetate.svg
C17β Ethanoic acid Straight-chain fatty acid 2 1.14 0.88 Short
Metenolone enanthate
Metenolone enanthate.png
C17β Heptanoic acid Straight-chain fatty acid 7 1.37 0.73 Long
Nandrolone decanoate
Nandrolone decanoate.svg
C17β Decanoic acid Straight-chain fatty acid 10 1.56 0.64 Long
Nandrolone phenylpropionate
Nandrolone phenylpropionate.svg
C17β Phenylpropanoic acid Aromatic fatty acid – (~6–7) 1.48 0.67 Long
Trenbolone acetate
Trenbolone acetate.svg
C17β Ethanoic acid Straight-chain fatty acid 2 1.16 0.87 Short
Trenbolone enanthated
Trenbolone enanthate.svg
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 androgen/anabolic steroid content by weight (i.e., relative androgenic/anabolic potency). c = Duration by intramuscular or subcutaneous injection in oil solution. d = Never marketed. Sources: See individual articles.

See alsoEdit

ReferencesEdit

  1. ^ Richard Lawrence Miller (2002). The Encyclopedia of Addictive Drugs. Greenwood Publishing Group. pp. 416–. ISBN 978-0-313-31807-8.

Further readingEdit