Anabolic/androgenic steroids may influence the size of the prostate. Androgens are integral to the development of the prostate in early life, and are essential to maintaining prostate structure and function throughout adulthood. Increases in the androgen level often result in growth stimulation to this gland (prostate hypertrophy). For example, increased prostate volume has been reported in some patients receiving testosterone injections for the treatment of hypogonadism. While extreme prostate hypertrophy is not common under therapeutic conditions, prostate volume does tend to reach a size that is considered normal for a given androgen level. PSA (prostate-specific antigen) levels have also been shown to increase under the influence of exogenous testosterone in some patients, which is a diagnostic marker of prostate health often correlated with prostate volume. Additionally, reducing stimulation of the prostate by lowering the androgen level tends to reduce prostate volume.
Anabolic/androgenic steroid abuse may result in significant increases in prostate volume. In more severe cases, this may lead to benign prostate hypertrophy (BPH). BPH is a common condition in older men, characterized by reduced urine flow, difficulty or discomfort urinating, and changes in urinary frequency. Anecdotal reports of BPH among steroid-using bodybuilders are not common, but do occur with enough frequency to warrant concern. Such reports are most often linked to more androgenic drugs such as testosterone and trenbolone, or the excessive dosing of AAS in general. One of the most extreme reports of prostate hypertrophy came from Dr. John Ziegler, the U.S. Olympic physician accredited with introducing Dianabol to sports. Dr. Ziegler noted that during the mid-1950s, many Russian weightlifters were abusing so much testosterone that they needed catheterization to urinate. Dianabol was released soon after, which is structurally a close derivative of testosterone with reduced androgenicity.
Studies of anabolic/androgenic steroid abusers show a preferential stimulation of the inner prostate under the influence of these drugs, in an area where benign prostate hypertrophy is known to originate. In contrast, prostate cancer usually develops in peripheral areas of the gland. Some association between BPH and prostate cancer is known to exist, however, although the exact nature and strength of this association remains uncertain. PSA values are often (although not always) elevated in both disorders, and serve as a marker of potential trouble. It is important for men to monitor prostate health regularly by digital rectal examinations and blood testing for PSA levels. Anabolic/androgenic steroid use is generally immediately discontinued if signs of BPH or elevated PSA values become apparent.
In addition to androgens, estrogens are also known to be involved in prostate growth and functioning. While androgens are generally stimulatory towards prostate growth, however, estrogen exerts both protective and adverse effects. On the beneficial side, stimulation of estrogen receptor (ER-beta subtype) may help protect the prostate from inflammation, cell hyperplasia, and carcinogenesis. Conversely, stimulation of the alpha subtype of the estrogen receptor is linked to abnormal cell proliferation, inflammation, and carcinogenesis. How the aromatization of testosterone and AAS (which will result in stimulation of both receptor subtypes) will effect prostate hypertrophy remains unclear. Prostate growth and elevated PSA values have been noted during steroid administration with both strongly and mildly estrogenic steroids. Furthermore, the administration of anastrozole (an inhibitor of estrogen synthesis) during testosterone administration does not appear to block stimulation of the prostate. Presently, the most successful strategy to minimizing prostate hypertrophy seems to be focused on reducing relative androgenic, not estrogenic, action.
Wlliam Llewellyn (2011) - Anabolics