Benign Prostatic Hyperplasia (BPH) describes the non-cancerous, age-related enlargement of the prostate gland. This condition is prevalent in men as they get older and can cause bothersome lower urinary tract symptoms. For decades, a major concern was whether introducing supplemental testosterone, such as through Testosterone Replacement Therapy (TRT), could worsen BPH symptoms or accelerate prostate growth. The fear was that increasing the body’s androgen levels would directly fuel the enlargement process, creating a dilemma for men who needed TRT but also had BPH.
Understanding How Testosterone Affects Prostate Size
The relationship between testosterone and prostate size involves a powerful conversion process. Testosterone is necessary for prostate health, but it is a secondary actor in stimulating BPH growth. The primary driver of prostate cell proliferation is a much more potent androgen called dihydrotestosterone (DHT).
Testosterone is converted into DHT within the prostate cells by the enzyme 5-alpha reductase (5-AR). DHT binds to androgen receptors with a much stronger affinity than testosterone. This binding signals cells to grow and divide, leading to the gradual enlargement defined as BPH.
BPH is not caused by abnormally high levels of circulating testosterone; many men with BPH have declining testosterone levels as they age. Instead, the prostate tissue becomes increasingly sensitive to existing DHT levels over time, causing the gland to grow steadily throughout adulthood.
Current Scientific Consensus on Testosterone Therapy and BPH
The historical concern that testosterone therapy would worsen BPH symptoms stemmed from an outdated understanding of androgen dynamics. Contemporary research has shifted this perspective, especially for hypogonadal men (those with clinically low testosterone levels). TRT is not a treatment for BPH, but it is generally considered safe for men with stable BPH who require it for symptoms of low testosterone.
This change is supported by the “androgen saturation model,” which proposes that prostate androgen receptors become saturated at relatively low testosterone levels. Once occupied by DHT, increasing systemic testosterone through therapy does not significantly stimulate further prostate growth. Studies show that TRT in hypogonadal men does not lead to a substantial increase in prostate volume beyond a minimal initial rise, which then plateaus.
Clinical trials monitoring men receiving TRT found no significant difference in the progression of lower urinary tract symptoms (LUTS) compared to a placebo. In some cases, TRT has been associated with improved LUTS, possibly by reducing inflammation or improving bladder function. A major randomized trial tracked prostate outcomes for over two years and found no increase in prostate cancer incidence or progressive urinary symptoms.
For men with mild to moderate BPH, TRT is not contraindicated, but it necessitates careful monitoring by a physician. The doctor will regularly check prostate-specific antigen (PSA) levels and assess urinary symptoms using standardized questionnaires. TRT is generally avoided in men with severe, untreated LUTS or those with a history of prostate cancer.
Established Treatment Approaches for an Enlarged Prostate
Since testosterone therapy is not intended to treat BPH, physicians rely on established methods to reduce prostate size or alleviate urinary symptoms. The first line of defense involves simple lifestyle adjustments, such as managing fluid intake before bedtime and reducing consumption of caffeine and alcohol.
When symptoms become more bothersome, medication is introduced. Alpha-blockers (e.g., tamsulosin or alfuzosin) work by relaxing the smooth muscles in the prostate and bladder neck. This relaxation improves urine flow and relieves symptoms quickly, but these medications do not shrink the prostate gland itself.
Another class of medications is the 5-alpha reductase inhibitors (finasteride and dutasteride). These drugs target the underlying mechanism of BPH by blocking the 5-AR enzyme, preventing the conversion of testosterone into DHT. By reducing DHT levels, these inhibitors actively shrink the prostate gland and are prescribed for men with significantly enlarged prostates.
Minimally Invasive Procedures and Surgery
For severe cases where medication is ineffective or complications arise, minimally invasive procedures and surgery are options. Procedures like the UroLift system use small implants to hold open the blocked urethra. GreenLight laser therapy vaporizes obstructing prostate tissue. The traditional surgical standard for substantial blockage remains transurethral resection of the prostate (TURP), which removes excess tissue through the urethra.