TRT & BPH: Dispelling Old Myths on Prostate Enlargement

Written by Adam Maggio | Medically reviewed by Dr. Mitchell Ross, MD, ABAARM

Modern evidence shows TRT does not worsen BPH symptoms or cause significant prostate growth in hypogonadal men. The 'saturation kinetics' model suggests restoring physiological testosterone levels is safe for the prostate, often improving LUTS.

TRT and Benign Prostatic Hyperplasia (BPH): Dispelling Old Myths

Benign Prostatic Hyperplasia (BPH), or an enlarged prostate, is a common condition affecting aging men, leading to bothersome lower urinary tract symptoms (LUTS) such as frequent urination, urgency, and weak stream. For many years, a prevailing concern was that Testosterone Replacement Therapy (TRT) would exacerbate BPH symptoms or promote prostate growth. However, modern evidence largely contradicts this long-held belief.

The historical apprehension stemmed from the understanding that androgens, including testosterone and its more potent metabolite dihydrotestosterone (DHT), are essential for prostate development and growth. It was logically, though incorrectly, assumed that introducing exogenous testosterone would inevitably lead to further prostate enlargement and worsening BPH symptoms. This led to a reluctance to prescribe TRT to men with hypogonadism and concomitant BPH.

However, numerous contemporary studies and meta-analyses have demonstrated that TRT does not significantly worsen BPH symptoms or cause clinically meaningful prostate growth in men with hypogonadism. In fact, some studies have even shown an improvement in LUTS with TRT. For instance, a systematic review by Baas et al. (2016) concluded that current evidence suggests TRT not only does not worsen LUTS but that hypogonadism itself may be an important risk factor for LUTS.

The concept of "saturation kinetics," similar to its application in prostate cancer, also applies to BPH. The prostate gland, once exposed to physiological levels of testosterone, becomes saturated with androgens. Further increases in testosterone within the physiological range do not lead to additional prostate growth. This means that restoring testosterone levels from a deficient state to a healthy normal range is unlikely to cause the prostate to grow beyond what it would naturally achieve with adequate endogenous testosterone.

It's important to differentiate between the initiation of TRT in a hypogonadal man and the effects of supraphysiological testosterone levels. The goal of TRT is to restore testosterone to a healthy, youthful range, not to exceed it. Unlike the prostate's response to very low testosterone (which can paradoxically lead to some BPH symptoms due to altered androgen-estrogen balance) or extremely high, supraphysiological levels, normal physiological levels appear to be well-tolerated.

Moreover, some research suggests that low testosterone itself might contribute to BPH progression or symptoms. The complex interplay between testosterone, estrogen, and DHT in the prostate is still being fully elucidated. However, the current consensus is that TRT, when properly administered and monitored, is safe for men with BPH and hypogonadism.

Unlike medications specifically designed to shrink the prostate or relax bladder muscles (e.g., alpha-blockers or 5-alpha-reductase inhibitors), TRT's primary role is to restore hormonal balance. While it may indirectly improve some LUTS by improving overall prostate health and reducing inflammation, it is not a direct treatment for BPH. However, it can be safely co-administered with BPH medications.

In clinical practice, we frequently encounter men with both symptomatic hypogonadism and BPH. A 68-year-old patient with an International Prostate Symptom Score (IPSS) of 15 and a total testosterone of 210 ng/dL can be confidently started on TRT. We've observed that many such patients report no worsening of their urinary symptoms, and some even experience mild improvements, alongside the expected benefits of TRT on energy, mood, and libido. Regular monitoring of LUTS and PSA is, of course, still part of standard care.

The practical takeaway is that the fear of TRT worsening BPH symptoms is largely unfounded by modern scientific evidence. For men with diagnosed low testosterone and BPH, TRT can be safely initiated and continued under appropriate medical supervision. It is not a contraindication. Discuss your BPH symptoms and hormonal status with your physician to determine if TRT is an appropriate part of your overall health management plan, ensuring regular monitoring of prostate health parameters.