Effects of Steroids

Anabolic steroids are very important organic compounds, which act as hormones within the human body that are either Testosterone itself, or they are identical to Testosterone and/or mimic Testosterone’s actions with other variations in their observable effects. The effects of steroids as hormones and analogues/derivatives of hormones are very diverse, and while Testosterone, for example, might exhibit favorable effects in one or two areas of the human body it might also exhibit unfavorable or unwanted effects in others. This is the normal trade-off when it comes to the use of anabolic steroids, or almost anything in this world. This is why anabolic steroids hold such a wide array of application in science and medicine, which can be attributed to their diverse governance on the different systems of the body. In terms of anabolic steroid analogues and derivatives, which are modified variants of Testosterone, the different effects of steroids can then be changed in order to create a more favorable effect in a particular area of the body while reducing the extensiveness of its effects on another system or area of the body. This was one of the original goals of the anabolic steroid development boom of the 1950s.

During the 1950s, many pharmaceutical corporations raced frantically to attempt to create the ‘perfect’ anabolic steroid, which could be defined as an anabolic steroid that would exhibit all of the effects of steroids that would be favorable and desirable (such as the increases in strength and muscle mass) without any of the negative effects of steroids that might be unfavorable (such as the estrogenic and androgenic effects). Although no perfect anabolic steroid was ever created, science did come very close with the development of a select few anabolic steroids, such as Anavar (Oxandrolone). Regardless, the nature of anabolic steroids is such that the anabolic (tissue building) effects cannot be completely separated from the androgenic (masculinizing) effects, as the two are intrinsically intertwined. Only a distinct distancing of the two might be possible to a certain extent, but never a total elimination or separation of them. However, the many different anabolic steroid analogues in existence provide individuals with the ability to select and choose which anabolic steroid might be more favorable to their needs according to each anabolic steroid’s effects.
Trenex 100There are many different anabolic steroid analogues and derivatives, and they are derived from one of three primary hormones that are naturally created and found within the human body. They are: Testosterone, Nandrolone, and Dihydrotestosterone (DHT). Essentially, all anabolic steroid derivatives are derivatives of Testosterone, as Testosterone is in fact the precursor for Nandrolone and Dihydrotestosterone. Without Testosterone, either of the latter two would exist. However, once isolated in a laboratory, Nandrolone and Dihydrotestosterone themselves can be directly modified at their chemical structures in order to create an analogue or derivative of whichever hormone is being modified (known as the parent or progenitor hormone). Trenbolone, for example, is a derivative of the parent hormone Nandrolone. Boldenone (Equipoise), for example, is an analogue/derivative of Testosterone, which is its parent/progenitor hormone. Each of these hormones share close properties with their parent hormones by virtue of the fact that they are derived from them, but in some rare occasions the derivative hormone is very much capable of exhibiting completely different properties that might seem to go against the logic in regards to the effects of steroids being shared or passed down from the progenitor hormone to its derivative. Anadrol (Oxymetholone) is one such example, which is a derivative of DHT. Derivatives of DHT should normally exhibit no estrogenic effects on the body by virtue of the fact that they cannot convert (aromatize) into Estrogen. Although Anadrol too cannot aromatize, the current hypothesis is that it (or its metabolites) seems to act as an Estrogen itself in various tissues of the body[1]. This is a perfect example of how various anabolic steroids will exhibit different effects than others, and perhaps some will exhibit unpredictable effects in comparison to others.

The effects of steroids can essentially be categorized and generalized into two primary types:

1. Desirable (positive) effects of steroids
2. Undesirable (negative) effects of steroids

What enables an anabolic steroid to exhibit positive or negative (desirable or undesirable) effects is very much limited to individual the individual, which makes the effects of steroids very relative (to the individual). For example, while many might regard the hair growth effect of steroids to be undesirable, there are in fact many individuals who seek the use of anabolic steroids for this effect, which is desirable, and therefore a positive effect. With this having been established, on a general level there are effects of steroids that can be considered undesirable for most, which is why they are placed under the category of ‘undesirable effects of steroids’. In some cases, generalizations must be made even though in the abstract, such an issue is a grey issue rather than black and white. Another example of mixed opinions on an effect of steroids that might be desirable among some and undesirable among others is the fact that anabolic steroids for the most part tend to cause an increase in libido and sexual function[2]. Although rare, there are some individuals that regard such a large increase in libido and sex drive to be undesirable and/or very inconvenient. However, because the increase in libido and sexual function is one of the effects of steroids that is desired by the majority of the population, such an effect is then considered to be a desirable effect (even though, as previously mentioned, there exists a small percentage of the population that might regard the libido increases as an undesirable and therefore negative effect of steroids).

Desirable (Positive) Effects of Steroids

The reason as to why individuals elect to use anabolic steroids is because of their two primary desirable effects: physical athletic performance enhancement and physique enhancement. Everything else, and all other effects of steroids that an individual will experience during the course of an anabolic steroid cycle, whether desirable or undesirable, is secondary to this. Very rarely are anabolic steroids utilized without these two desirable effects as the primary goals in mind. In some cases, the off-label use of anabolic steroids might fall into a category of a desirable positive effect that an individual might be looking to use them for. It is only within medicine that the applications of anabolic steroids are utilized without the two aforementioned desirable effects in mind. Various uses within medicine will be periodically mentioned and covered here as the effects are described. It has been previously mentioned in the introduction that anabolic steroids exhibit a vast array of effects on the subsystems of the human body due to their nature as hormones, and many of these effects are the desired effects of steroids on the human body where the medical establishment is concerned. For the purpose of physique and performance enhancement, which is what this article is most centered on, it is a slightly different story.

Protein synthesis increase:
The muscle growth and strength benefits resultant from anabolic steroid use technically occur through various separate pathways and include both direct as well as indirect anabolic effects, but for the purpose of this article, the effects of steroids in relation to muscle growth and strength increases will be simplified so as to discuss the major pathways, and for ease of a layman’s understanding in this subject. The mechanisms by which Testosterone and every anabolic steroid analogue/derivative operates is very well documented and experimented upon over the previous 70 or more years. However, the process by which anabolic steroids exactly and precisely influence muscle mass in all aspects and mechanisms is still not completely understood. It is presently understood that the primary means of action in terms of protein synthesis increase in muscle tissue is by way of the anabolic steroid binding to the cellcular androgen receptor, activating it, and essentially transmitting a message to the muscle cell to begin increases in protein synthesis. This, however, cannot occur without proper physical stimulation beforehand (through resistance training exercise), and hence why the common myth that anabolic steroids will make an individual big and muscular without any proper training or nutrition is simply not true.

Aside from receptor interaction/activation, it is well known that an effect of steroids on muscle growth is also through its ability to activate and affect the secretion and release of other muscle growth promoting hormones (such as IGF-1 and MGF) that hold an equally effective influence on muscle growth[3], which might interact with other difference receptor types within muscle tissue. This creates a synergistic effect between the anabolic steroid and the other auxiliary hormones involved and interconnected in muscle growth. Evidence of this can be seen in various anabolic steroids that in fact do not exhibit very significant binding strength to the androgen receptor, such as Dianabol (Methandrostenolone) where its effects lie in non-receptor mediated effects as evidenced by a particular study utilizing high doses of the compound that demonstrated a high level of nitrogen retention in the muscles promoted by Dianabol[4]. Anadrol (Oxymetholone) is another such anabolic steroid that exhibits poor androgen receptor binding strength but is known to be a very strong anabolic agent[5]. In contrast, we can see how the effects of steroids differ between different steroids when we see how Testosterone itself in various studies has been found to exhibit no increases in tissue amino acid transport but indeed increases protein synthesis[6].

Muscle growth from anabolic pathways caused by steroids

Increases in collagen synthesis and bone mineral content:
All anabolic steroids to one degree or another exhibit the ability to increase bone strength through stimulation of increased collagen synthesis, an increase in bone mineral storage content, increases in new bone construction, and the inhibition of the resorption of bone (bone breakdown)[7]. Collagen is the protein-based construction material that composes the key connective tissues throughout the body (the joints, ligaments, tendons, cartilage, and bones themselves). This tissue is what holds the different components of the body together, and there even exists collagen intertwined throughout muscle tissue itself (the connective tissue between bundles of muscle fibers which holds the bundles together to form the muscle belly). Even at relatively low HRT (Hormone Replacement Therapy) and TRT (Testosterone Replacement Therapy) doses of anabolic steroids, the effects of steroids on bone and connective tissue strength are quite profound and well-documented. It is the major reason as to why anabolic steroids are utilized in medicine for the purpose of osteoporosis treatment, and for the accelerated healing of bone fractures and bone frailty problems[8]. Studies have demonstrated that only 250mg of Testosterone Enanthate administered only once every 21 days (an extremely low dose by performance enhancement standards) had demonstrated a 5% bone mineral density increase over a 6 month period[9]. Such an increase from such a small and infrequent administration of Testosterone should provide a strong indication of the very beneficial effects of steroids on individuals with bone frailty associated with aging (or for any other reason, especially the healing of bone injuries such as fractures).

It is already very well known that a deficiency in endogenous androgen levels for any reason, such as aging (andropause), and hypogonadism, exhibit reduction in overall body height due to the natural deterioration of bone with age, as well as many other shortcomings in physical ability[10]. This natural deterioration of bone with age results in a decreased body height, which is ultimately the result of decreased endogenous Testosterone production with age (once again, properly termed andropause). This is very evident especially even in females, whom naturally possess a significantly lower androgen level (accompanied with a high Estrogen level) than males (0.25mg daily in comparison to the male daily production of 2.5 – 11mg daily)[11]. As a result, females exhibit a naturally shorter bodily height, far less muscle tissue than males, and are far more prone to age-related bone frailty (osteoporosis) in comparison to men. For the athlete, these immense bone strengthening effects of steroids are very useful and very profound, where their use in sports that involve heavy contact and excess stress on the skeletal system would be assisted in a very positive and desirable way with the use of anabolic steroids.

Increased nutrient partitioning:
Technically belonging under the category of increased protein synthesis, the enhanced nutrient partitioning effects of anabolic steroids deserve their own descriptive portion. It is commonly assumed by many that anabolic steroids possess significant fat burning effects. The truth is that although many anabolic steroids do exhibit activity with the androgen receptor on adipose tissue (fat tissue), it is not through this pathway that any significant fat loss occurs, which would be considered a direct effect on fat loss. The fat loss resultant from the androgen receptor activity in fat cells is not very significant. However, it is in fact through indirect effects on fat loss by which the fat loss during an anabolic steroid cycle occurs. It is through the muscle growth and protein synthesis signaling effects on muscle tissue (mentioned earlier) that this very strong nutrient partitioning effect occurs.

The effects of steroids on the pathway of nutrient use by the body is very profound, whereby once a large amount of muscle cells have been signaled to effectively initiate protein synthesis and engage in muscle cell repair and growth, the body will now partition (or ‘shuttle’) more nutrients consumed (protein, fats, carbohydrates, and even vitamins and minerals) to the muscle tissue for the purpose of muscle repair and muscle growth. With more muscle cells activated to engage in protein synthesis, the percentage of consumed calories to be utilized for this purpose now increases drastically. It is very obvious what this means for muscle growth: more muscle growth, quicker muscle growth, and faster muscle growth, provided the nutritional intake is adequate. But what does this mean for fat loss? In a direct sense, the enhanced nutrient partitioning does not metabolize fat directly, but with now more consumed nutrients being shuttled towards muscle growth and less towards fat storage, this opens a wider window and opportunity for the body to utilize fat storage for energy while fewer nutrients are being stored as fat.

This increased nutrient partitioning is the number one key reason as to why anabolic steroids are utilized in farm cattle, so as to increase the feed efficiency and output of lean meats as opposed to fatty meats. More meat for consumer consumption means more of the population can be effectively fed for a lower cost of production. Trenbolone is the primary anabolic steroid utilized to improve feed efficiency and fat-free mass addition in cattle, where it has been proven in studies to exceptionally reduce the concentration of fat deposits and drastically increase protein content (in the form of lean muscle tissue) in farm animals[12].

Increased hemoglobin (red blood cell count):
This could possibly be considered both a desirable (positive) as well as an undesirable (negative) effect of steroids. What separates whether or not this particular effect of steroids becomes good or bad is dependent on how high an individual’s hemoglobin levels rise as a result of use. For those unaware, the term ‘hemoglobin’ and ‘red blood cells’ go hand-in-hand. Hemoglobin is the protein contained in the center of each red blood cell, which is where oxygen becomes attached to when red blood cells travel to the lungs to pick up oxygen. The red blood cell then travels to various tissues and cells throughout the body to deliver the attached oxygen before returning to the lungs to allow more oxygen to attach to the hemoglobin protein. Therefore, a rise in hemoglobin levels will always correlate with a rise in red blood cell count.

Anabolic steroids stimulate cells in the kidneys to begin or increase the manufacture and secretion of a hormone known as Erythropoietin (EPO). This process is known as Erythropoiesis. EPO then travels to the bone marrow in order to signal the production of new red blood cells. It is through this process that anabolic steroids can and do increase red blood cell production, which is very beneficial for athletes looking to utilize anabolic steroids for their endurance increasing benefits on performance. Within medicine, anabolic steroids are utilized for the treatment of anemia, which is a condition whereby an individual manufactures insufficient red blood cells (for many different reasons), or expresses a low red blood cell count for various other reasons. The effects of steroids on the hematological system in this regard are extremely beneficial for anemic patients. Anadrol (Oxymetholone) is one such anabolic steroid that has been specifically utilized almost exclusively for the treatment of severe anemic patients, as its efficiency at such a function has been proven to be exceptional even in anemic patients that have exhibited bone marrow failure[13].

Anti-glucocorticoid effects:
All anabolic steroids exhibit what is known as an anti-catabolic effect on muscle tissues by way of acting as an anti-glucocorticoid. Glucocorticoids are steroid hormones known as corticosteroids, which act as stress hormones in the body and serve to do the exact opposite of anabolic steroids to muscle tissue: they destroy and break down muscles. Anabolic steroids have demonstrated to be very effective suppressants of corticosteroids (glucocorticoids) in the body[14]. Corticosteroids engage in the breakdown of muscle tissue (catabolism) into amino acids as a stress response when the human body senses impending starvation or danger, and requires an immediate supply of nutrients in the bloodstream. Glucocorticoids not only act to break muscle tissue down into amino acids, but also serve to cause a breakdown of carbohydrates (from both the liver and muscle tissue) for release as blood glucose, as once again, a stress response. While some moments might initiate a high level of glucocorticoid activity in this sense, other moments will normally express a lower and slower level of activity. Nevertheless, corticosteroids are constantly breaking down muscle tissue at a constant rate, though normal physiological functions should dictate a slow but steady rate. If an athlete or bodybuilder places his or her body within the proper parameters in nutrition and training, the individual’s body will offset the balance of anabolism and catabolism to favor that of anabolism, whereby more protein will be stored and constructed as muscle tissue than there is being broken down (or catabolized) by glucocorticoids.

The introduction of anabolic steroids at supraphysiological levels into the body can shift the balance of anabolism to catabolism in vast favor of anabolism far beyond what the body could achieve naturally. It will not only increase the anabolic effects of steroids, but at the same time increase the suppressive effect of the catabolic effect of corticosteroids (glucocorticoids) by way of androgens causing glucocorticoids to be removed from their respective glucocorticoid receptors in muscle cells as demonstrated by studies[15]. It has also been discovered through studies that androgens, such as Testosterone, will interfere with the DNA transcription process caused by glucocorticoid effects on the glucocorticoid receptors in muscle cells[16].

Undesirable (Negative) Effects of Steroids

Susta-T 250The majority of the undesirable and negative effects of steroids are, for the most part, very superficial cosmetic effects (such as acne, potential hair loss, or gynecomastia). There exist several internal negative effects of steroids, but these are just as temporary while on a cycle as the undesirable cosmetic effects are. This article will cover the most questioned, and for the lack of a better term, the most popular of the negative effects of steroids among individuals. It is important to understand the dynamics by which the negative effects of steroids work, and it is highly encouraged that individuals read the steroids side effects article for an all-encompassing in-depth coverage of all of the side effects of anabolic steroids and how and why they occur. This is not an all-inclusive list of the side effects of steroids, and it is very important for all readers to understand this. The five primary negative effects of steroids are acne, gynecomastia, male pattern baldness (MPB), hepatotoxicity (liver toxicity).

Acne:
Perhaps the most superficial effect resultant of anabolic steroids, it tends to also be the most concerning among individuals looking to use anabolic steroids. This is likely because although one might desire a muscular physique, it might be embarrassing to unveil a physique that could potentially be covered in unsightly acne. Anabolic steroids (but more specifically their highly androgenic metabolites, such as Dihydrotestosterone) affect androgen receptors located underneath the skin and the scalp, and through this they signal the sebaceous glands to begin or increase the secretion of sebum, which are the naturally occurring skin oils. The effects of steroids here in this particular area are also known for increasing the size of these glands[17].

Acne from anabolic steroid absue

Excessive sebaceous gland stimulation can result in follicles and pores becoming overloaded with sebum, dead skin, and dirt which results in acne. This is not regarded as a life-threatening side effect and ranges in severity between individuals so much so that some may not experience acne at all, others may experience minor acne, and some will experience severe breakouts. The rate at which this affects individuals varies, and there is no general description as to how much or how little of an acne breakout an individual might experience on an anabolic steroid cycle. Although there are several medications and/or treatments (including topical treatments) for the prevention or inhibition of this effect, the buildup of sebum and/or the resultant acne is usually cleared with the discontinuation of anabolic steroids not very long following the termination of an anabolic steroid cycle.

Gynecomastia:
This is, without a doubt, the second most concerning effect that certain anabolic steroids can have upon a person. Every individual will hear about the effect of gynecomastia (AKA ‘gyno’ or ‘bitch tits’) in one way or another, whether it be hearsay among friends, or through the media. Gynecomastia is the development of breast tissue on the male chest area. It is the result of rising Estrogen levels as a result of aromatization (conversion) of aromatizable androgens into Estrogen by the aromatase enzyme, which is the enzyme responsible for this conversion. Not all anabolic steroids can aromatize into Estrogen, and many exist that are unable to interact with the aromatase enzyme what so ever, but there are various anabolic steroids that do, such as Testosterone, Boldenone (Equipoise), Nandrolone (Deca Durabolin), Dbol (Methandrostenolone), and a few others. Estrogen is the primary culprit here in the development of breast tissue where it binds to receptors in breast tissue and initiates the growth processes of ductal epithelial hyperplasia, ductal elongation, and fibroblast proliferation[18]. On the other hand, androgens actually work to inhibit breast tissue growth[19], which serves to explain why Dihydrotestosterone (DHT) is one of the body’s natural and effective anti-Estrogens.

Gynecomastia can be prevented with the use of Estrogen blockers that block the effect of Estrogen at the breast tissue site, or through the use of aromatase inhibitors which serve to inhibit and disable the aromatase enzyme. The severity, intensiveness, rate of growth, and whether or not this condition may actually manifest itself is dependent on the type of anabolic steroids utilized, the dose, duration of use, as well as the number one determining factor: individual sensitivity to this particular side effect. Many individuals will never experience gynecomastia at all no matter how high Estrogen levels in the body rise, while others may suddenly experience breast tissue development at the sudden onset of the most minimal rise in Estrogen levels. If gynecomasta develops beyond a particular stage, it is considered irreversible even with ancillary compounds, and the only option for removal is that of surgery. The ‘point of no return’ is usually marked by glandular tissue development (when the gland has actually formed underneath the fatty tissue).

Male pattern baldness (MPB):
Also known as hair loss, this is another very infamous effect of steroids that tends to deter many individuals that highly value their scalp hair. The truth is, however, that male pattern baldness is not caused by anabolic steroids but is instead caused by genetics – anabolic steroids simply serve to accelerate the genes responsible for MPB if the individual indeed possesses the genetic trait for such an effect.  Evidently, this is one of the many effects of steroids that is very poorly understood.

Male Pattern Baldness (MPB) from anabolic steroids (DHT)

As mentioned previously under the acne effect, anabolic steroids can bind to androgen receptors located in the scalp, and through this, trigger male pattern baldness in individuals that possess the genetic trait required for the condition to manifest itself and can occur in both men as well as women. Those who do not possess this genetic trait required will not experience this effect at any dose at all. This is why there are individuals that can utilize the most androgenic anabolic steroids, such as Tren over and over again in cycle after cycle for years, and still end up with a full head of hair in their old age. There are various ancillary compounds and topical treatments (such as Nizoral 2% shampoo) that work to prevent or lessen the chances of MPB of occurring in individuals that might be afraid they possess the genetics for such a condition. In general, however, the issue of MPB is one that can never be completely prevented, and the risk will always exist for those who possess the genes required for the condition to trigger itself, and therefore the best course of action for those who do not wish to impose any risk of MPB on themselves at all is to completely avoid the use of all anabolic steroids and any anabolic steroid use at all.

Hepatotoxicity (liver toxicity):
A similarly misunderstood effect of steroids (as with all effects of steroids), the issue of liver toxicity is, for the most part, limited only to oral anabolic steroids which possess the chemical modification known as C17-alpha alkylation (also known as methylation at the 17th carbon atom). All oral anabolic steroids must have previously undergone this specific modification in order to allow oral bioavailability. When Testosterone (or any other anabolic steroid) is ingested orally, too little of the anabolic steroid will enter the bloodstream to impact any significant effects on the body. Unfortunately, nearly all anabolic steroids are very easily metabolized and broken down by the liver, leaving a very miniscule percentage that actually survives this liver metabolism. C17-alpha alkylation enables the anabolic steroid to resist liver metabolism and enter the bloodstream, however, at the expense of varying degrees of heightened liver toxicity. Anabolic steroids that do not possess this chemical modification (which means almost all injectable anabolic steroids) do not exhibit any measurable amounts of liver toxicity in healthy individuals, as evidenced by various studies conducted.

For example, one particular study investigated the use of Testosterone at high doses (400mg daily, which equates to 2,800mg weekly) in several male test subjects for a 20 day period where the route of administration was actually oral instead of intramuscular injections. The idea behind administering pure Testosterone orally is to saturate the liver with high amounts of Testosterone (all orally ingested substances make what is known as a ‘first pass’ through the liver and interact with the liver at a far greater rate than the injectable route of administration). The result of the study was that no changes in liver toxicity were observed[20]. This is in direct contrast with oral C17-alpha alkylated steroids, which have demonstrated levels of liver toxicity rising at even minor doses. For example, Dianabol in one study was administered at doses of 15mg per day or more had resulted in elevated bromosulphalein levels (an indication of increased hepatic strain), and at doses of 10mg or less per day displayed minimal hepatic strain[21]. Dianabol is a perfect example, as 15mg daily is considered by bodybuilding standards to be a very low dose, and when the average beginner dose is upwards of 25mg daily, the level of hepatotoxicity from a C17-alpha alkylated oral such as Dianabol should be placed into perspective for the reader.

 

Medical References:
 
 
[1] Review of oxymetholone: a 17alpha-alkylated anabolic-androgenic steroid. Pavlatos AM, Fultz O, Monberg MJ, Vootkur A, Pharmd. Clin Ther. 2001 Jun;23(6):789-801; discussion 771.
 

[2] Sexual functioning of male anabolic steroid abusers. Moss HB, Panzak GL, Tarter RE. Arch Sex Behav. 1993 Feb;22(1 ):1-12.

[3] Ontogeny of growth hormone, insulin-like growth factor, estradiol and cortisol in the growing lamb: effect of testosterone. Arnold AM, Peralta JM,Tonney MI. J Endocrinol 150 (1996) 391-9 12.Jun;130(6):3677-83. 81, 2001.

[4] Effects of methandienone on the performance and body composition of men undergoing athletic training. Hervey GR, Knibbs AV, Burkinshaw L, Morgan DB, Jones PR, Chettle DR, Vartsky D. Clin Sci (Lond). 1981 Apr;60(4):457-61.

[5] Endocrinology 114(6):2100-06 1984 June,”Relative Binding Affinity of Anabolic-Androgenic Steroids ~ Saartok T; Dahlberg E; Gustafsson JA

[6] Testosterone injection stimulates net protein synthesis but not tissue amino acid transport. Fernando A, Tipton K, Doyle 0 et al. Am J. Physiol (Endocrinology and Metabolism) 38:E864-71,1998.

[7] Anabolic steroids in postmenopausal osteoporosis. Need AG et al. Wien Med Wochenschr. 1993;143(14-15):392-5.

[8] Nandrolone decanoate: pharmacological properties and therapeutic use in osteoporosis. Geusens P. Clin Rheumatol. 1995 Sep;14 Suppl 3:32-9.

[9] Osteoporosis in male hypogonadism: responses to androgen substitution differ among men with primary and secondary hypogonadism. Schubert

M, Bullmann C et al. Horm Res. 2003;60(1 ):21-8.

[10] Age related testosterone level changes and male andropause syndrome. Wu CY, Vu TJ, Chen MJ. Chang Gung Med J. 2000 Jun;23(6):348-53.

[11] Role of androgens in growth and development of the fetus, child, and adolescent. Rosenfield R.L. Adv Pediatr. 19 (1972) 172-213.

[12] Influence of trenbolone acetate combined with estradiol-17 beta on growth performance, body characteristics, and chemical composition of goat kids fed milk and slaughtered at different ages. Schmidely P, Bas P, Rouzeau A, Hervieu J, Morand-Fehr P. J Anim Sci. 1992 Nov;70(11):3381-90.

[13] Oxymetholone treatment for the anemia of bone marrow failure. Alexanian R, Nadell J, et al. Blood. 1972;40:353-6.

[14] Glucorticoid antagonism by exercise and androgenic-anabolic steroids. Hickson RC, Czerwinski SM, Falduto MT, Young A~ Med Sci Sports Exerc 22 (1990) 331-40.

[15] Binding of glucorticoid antagonists to androgen and glucorticoid hormone receptors in rat skeletal muscle. Danhaive PA, Rousseau GG. J Steroid Biochem Mol Bioi 24 (1986) 481-71.

[16] Glucorticoid antagonism by exercise and androgenic-anabolic steroids. Hickson RC, Czerwinski SM, Falduto MT, Young AP. Med Sci Sports Exerc 22 (1990) 331-40.

[17] Effect of testosterone and anabolic steroids on the size of sebaceous glands in power athletes. Kiraly CL et al. Am J Dermatopathol, 1987 Dec, 9:6, 515-9.

[18] Estrogen regulation of mammary gland development and breast cancer: amphiregulin takes center stage. Heather L LaMarca and Jeffrey M Rosen. Breast Cancer Res. 2007; 9(4):304.

[19] Androgens and mammary growth and neoplasia. Dimitrakakis C, Zhou J, Bondy CA. Fertil Steril. 2002 Apr;77 Suppl 4:526-33.

[20] Enzyme induction by oral testosterone. Johnsen SG, Kampmann JP, Bennet EP, Jorgensen F. 1976 Clin Pharmacol Ther 20:233-237

[21] Anabolic steroids in clinical medicine. Liddle GW, Burke Jr. H A Helvetica Medica Acta, 5/6 1960:504-13.