**7. BoNT-A Injection for BPH**

BPH is the most common cause of bladder outlet obstruction in men. The prostate growth's anatomical obstruction may be the main reason for lower urinary tract symptoms, but inflammation, infection, and metabolic disorders can also be possible etiologies [76]. The prostate is innervated with the parasympathetic and sympathetic nerves [77]. The cholinergic nerves and muscarinic receptors are present in the fibromuscular stroma of the prostate, which can explain the previous beneficial effects of BoNT-A intraprostatic injection treatments [78–81]. However, a recent randomized controlled trial stated that high placebo effects appeared persistent and may be associated with the symptom improvement [14]. Several studies have shown that BoNT-A injection into prostate can effectively reduce pain in men with chronic prostatitis [82]. The effect of BoNT-A on male LUTS might result from anti-inflammation effect but not reducing the prostate volume [82]. Currently, BoNT-A injection treatment remains the less-common indication for men with BPH and lower urinary tract symptoms.
