Pharmacology is the study of drugs and their effects. Anabolic pharmacology is the study of drugs that have a growth-promoting effect in muscle. This column will explore anabolic pharmacology by profiling a different anabolic drug and its effects each month. The focus of discussion this month will be the anabolic androgenic steroid, dromostanolone.

Dromostanolone is a synthetic derivative of DHT. DHT binds more strongly to the AR than testosterone, but does not have an effect in muscle tissue, because it is deactivated by 3-alpha hydroxysteroid dehydrogenase. The methyl group at the 2^nd position allows dromostanolone to stay active in muscle tissue by disallowing deactivation by this enzyme to some degree. However, since dromostanolone is converted primarily to 2-methyl androsterone and 3-alpha diol derivatives, there is still considerable deactivation by 3-alpha hydroxysteroid dehydrogenase.¹

The presence of the 2-methyl group does reduce potency of dromostanolone compared to DHT, but only to about the level of testosterone. Since dromostanolone is already 5-alpha reduced, it is not converted any further by 5-alpha reductase. Therefore, it is equipotent or slightly less potent in skeletal muscle compared to prostate, hair follicles etc. Due to the fact that this steroid is 5-alpha-reduced, it cannot be converted to estrogenic metabolites. Additionally, 5-alpha-reduced steroids have been shown to have anti-aromatase activity.

The strong androgenic effect of dromostanolone, combined with its anti-estrogenic effects, can result in reduced levels of circulating SHBG. SHBG seems to have a protective role against estrogen-induced proliferation in the breast.^2,3,4,5,6,7 With the reduction of SHBG levels by dromostanolone, previously-bound estradiol and estrone circulate unbound and are much more likely to induce breast tissue growth in the environment of reduced SHBG. Dromostanolone is also known to result in hair loss and acne as well as prostate enlargement.

No binding to progesterone or glucocorticoid receptors has been shown with this steroid. Dromostanolone is traditionally injected as a propionate ester, requiring it to be injected every two or three days. It is a painful injection resulting in swelling and soreness. There are no legitimate producers of dromostanolone propionate at this time, only underground suppliers. I would not be surprised to see different esters of dromostanolone show up on the black market and there have been some reports of oral dromostanolone being sold.

Though many consider this steroid to be similar to DHT and expect side effects to be similar, dromostanolone is actually somewhat less harsh than DHT and other, more potent androgens. Its potency is similar to testosterone but without the conversion to estrogen which is demonstrated in its anabolic-to-androgenic ratio (about 3:1). Dromostanolone has been shown to build up red blood cells with a similar potency to oxymetholone⁸ and is known for its positive effects on strength.  Among users, this drug is known as a “hardener” because it loads water into the muscle without subcutaneous water retention (edema) resulting in a hard-looking physique.

Seth Roberts is a former pharmaceutical research scientist with over 10 years of pharmacological research in the discovery and development of novel therapeutics. Seth’s new book ANABOLIC PHARMACOLOGY is available now at www.Ergogens.com. [©Seth Roberts, 2009. All rights reserved. For informational purposes only, not to be considered as medical advice or an endorsement of the use of illegal substances.]

References:

1. Schanzer W: Metabolism of anabolic androgenic steroids. Clin Chem, Jul;42(7):1001-20, 1996.

2. Fortunati N, Raineri M, Cignetti A, Hammond GL, Frairia R. Control of the membrane sex hormone-binding globulin-receptor (SHBG-R) in MCF-7 cells: effect of locally produced SHBG. Steroids, 63(5-6):282-4, 1998.

3. Fazzari A, Catalano MG, Comba A, Becchis M, Raineri M, Frairia R, Fortunati N. The control of progesterone receptor expression in MCF-7 breast cancer cells: effects of estradiol and sex hormone-binding globulin (SHBG). Mol Cell Endocrinol, 172(1-2):31-6, 2001.

4. Försti A, Jin Q, Grzybowska E, Söderberg M, Zientek H, Sieminska M, etal. Sex hormone-binding globulin polymorphisms in familial and sporadic breast cancer. Carcinogenesis, 23(8):1315-20, 2002.

5. Catalano MG, Comba A, Fazzari A, Benedusi-Pagliano E, Sberveglieri M, Revelli A, et al. Sex steroid binding protein receptor (SBP-R) is related to a reduced proliferation rate in human breast cancer. Breast Cancer Res Treat, 42(3):227-34, 1997.

6. Fissore F, Fortunati N, Comba A, Fazzari A, Gaidano G, Berta L, Frairia R. The receptor-mediated action of sex steroid binding protein (SBP, SHBG): accumulation of cAMP in MCF-7 cells under SBP and estradiol treatment. Steroids, 59(11):661-7, 1994.

7. Fortunati N, Fissore F, Fazzari A, Berta L, Benedusi-Pagliano E, Frairia R. Biological relevance of the interaction between sex steroid binding protein and its specific receptor of MCF-7 cells: effect on the estradiol-induced cell proliferation. J Steroid Biochem Mol Biol, 45(5):435-44, 1993.

8. Sanchez-Medal L, Gomez-Leal A, Duarte L, Guadalupe Rico M. Anabolic androgenic steroids in the treatment of acquired aplastic anemia. Blood, 34(3):283-300, 1969.