ANABOLIC STEROIDS: BEYOND TESTOSTERONE
Structural modifications have been made to the testosterone molecule in an attempt to maximize the anabolic effects and minimize the androgenic ones; however, all AASs are virilizing if administered for long enough, athigh enough dosages [7]. AASs there fore include synthetic derivatives of testosterone,and not only testosterone itself. The AAS structural base is the ‘steran nucleus’[4],consisting of three condensed cyclohexanrings, in nonlinear junction, and acyclopentane ring (Fig. 1). The anabolic effects are dose-dependent, and usually occur when supra physiological testosterone levels(>1000 ng/dL) are found, which generally requires weekly doses of 300 mg or more.Traditionally, AASs are classified according to the route of administration and their carrier solvent and fall into two categories:1. Oral AASs or 17α-alkylated steroids. The 17α-alkylated AAS group originate from the substitution of the 17α-hydrogen on the steroid nucleus for a methyl or ethyl group.Alkyl substitution prevents deactivation of the steroid by hepatic first-pass metabolism(necessitating hepatic monitoring), which promotes oral activity. They usually have short half-lives, making several daily doses necessary to maintain appropriate blood levels. This class includes the very common stanozolol and oxandrolone, as well asmethyl testosterone and others.2. Parenteral AAS or 17β-esterified steroids.Usually the 17 β-hydroxyl group is oesterified with an acid moiety to prevent rapid release from the oily vehicle. Roughly, the longer the chain length of the acid moiety, the more slowly the preparation is released intothe blood stream. Once in the circulation,hydrolysis rapidly occurs yielding the active compound. They usually have a longer half life and a slower absorption rate, bringing much less hepatic stress than the orally taken steroids. Pain at injection sites is common,because of the oily base. There are four basic active compounds: i) testosterone, bound to esters such as undecanoate, cypionate, propionate and others; ii) 19-nortestosterone (or nandrolone), also bound to different esters. Nandrolone is extremely popular,owing to its high anabolic : androgenic ratio.In contrast to testosterone, nandrolone is converted to a less potent metabolite after 5α-reduction. This, in addition to nandrolone’s lesser affinity to AR,explains the higher myotrophic : androgenicratio; iii) boldenone, bound to esterundecylenate; and iv) trenbolone, bound to ester acetate. Anabolic-androgenic steroids may also be classified according to their main effects(Table 1). The main effects are as follows:‘Testosterone-like’ effect. The testosterone like effect is very potent, and allows great muscle strength gains. These AASs usually show an anabolic : androgenic ratio close to 1:1, similar to testosterone itself. The high aromatization rates are also comparable with those of testosterone. They include all testosterone esters, methyltestosterone and others.‘Dihydrotestosterone (DHT)-like’ effect. The DHT-like effect is potent but highly androgenic. As these AASs resemble a 5 DHT molecule, they cannot be aromatized to oestrogen and they also have a low water and salt retention. These AASs include stanozolol and oxandrolone. ‘Nandrolone-like’ effect. The nandrolone-like effect is the least potent of all highest anabolic : androgenic ratio. The AASsin this group have some progesterone-like activity, inhibiting the hypothalamic axis.These AASs are the most frequently used drugs in the clinical setting, when anabolic effects are desired (they reverse catabolic states, such as AIDS-associated cachexia, severe burns, and chronic obstructive pulmonary disease). They include the nandrolone esters and trembolone.
Guilherme Leme de Souza* and Jorge Hallak†*Department of Urology, Sao Paulo State Military Police Hospital, and †Division of Urology and PathologyDepartment, Reproductive Toxicology Unit, Hospital das Clinicas, University of Sao Paulo Medical School, Sao Paulo,Brazil
Structural modifications have been made to the testosterone molecule in an attempt to maximize the anabolic effects and minimize the androgenic ones; however, all AASs are virilizing if administered for long enough, athigh enough dosages [7]. AASs there fore include synthetic derivatives of testosterone,and not only testosterone itself. The AAS structural base is the ‘steran nucleus’[4],consisting of three condensed cyclohexanrings, in nonlinear junction, and acyclopentane ring (Fig. 1). The anabolic effects are dose-dependent, and usually occur when supra physiological testosterone levels(>1000 ng/dL) are found, which generally requires weekly doses of 300 mg or more.Traditionally, AASs are classified according to the route of administration and their carrier solvent and fall into two categories:1. Oral AASs or 17α-alkylated steroids. The 17α-alkylated AAS group originate from the substitution of the 17α-hydrogen on the steroid nucleus for a methyl or ethyl group.Alkyl substitution prevents deactivation of the steroid by hepatic first-pass metabolism(necessitating hepatic monitoring), which promotes oral activity. They usually have short half-lives, making several daily doses necessary to maintain appropriate blood levels. This class includes the very common stanozolol and oxandrolone, as well asmethyl testosterone and others.2. Parenteral AAS or 17β-esterified steroids.Usually the 17 β-hydroxyl group is oesterified with an acid moiety to prevent rapid release from the oily vehicle. Roughly, the longer the chain length of the acid moiety, the more slowly the preparation is released intothe blood stream. Once in the circulation,hydrolysis rapidly occurs yielding the active compound. They usually have a longer half life and a slower absorption rate, bringing much less hepatic stress than the orally taken steroids. Pain at injection sites is common,because of the oily base. There are four basic active compounds: i) testosterone, bound to esters such as undecanoate, cypionate, propionate and others; ii) 19-nortestosterone (or nandrolone), also bound to different esters. Nandrolone is extremely popular,owing to its high anabolic : androgenic ratio.In contrast to testosterone, nandrolone is converted to a less potent metabolite after 5α-reduction. This, in addition to nandrolone’s lesser affinity to AR,explains the higher myotrophic : androgenicratio; iii) boldenone, bound to esterundecylenate; and iv) trenbolone, bound to ester acetate. Anabolic-androgenic steroids may also be classified according to their main effects(Table 1). The main effects are as follows:‘Testosterone-like’ effect. The testosterone like effect is very potent, and allows great muscle strength gains. These AASs usually show an anabolic : androgenic ratio close to 1:1, similar to testosterone itself. The high aromatization rates are also comparable with those of testosterone. They include all testosterone esters, methyltestosterone and others.‘Dihydrotestosterone (DHT)-like’ effect. The DHT-like effect is potent but highly androgenic. As these AASs resemble a 5 DHT molecule, they cannot be aromatized to oestrogen and they also have a low water and salt retention. These AASs include stanozolol and oxandrolone. ‘Nandrolone-like’ effect. The nandrolone-like effect is the least potent of all highest anabolic : androgenic ratio. The AASsin this group have some progesterone-like activity, inhibiting the hypothalamic axis.These AASs are the most frequently used drugs in the clinical setting, when anabolic effects are desired (they reverse catabolic states, such as AIDS-associated cachexia, severe burns, and chronic obstructive pulmonary disease). They include the nandrolone esters and trembolone.
Guilherme Leme de Souza* and Jorge Hallak†*Department of Urology, Sao Paulo State Military Police Hospital, and †Division of Urology and PathologyDepartment, Reproductive Toxicology Unit, Hospital das Clinicas, University of Sao Paulo Medical School, Sao Paulo,Brazil
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