Blackmores Proseren contains a standardized extract of the herb saw palmetto (Serenoa repens). This formula is ideal for older men with frequent day or night urination, difficulty in starting or finishing urination, or a weak urinary flow. Benign prostatic hypertrophy (BPH) is a slow progressive enlargement of the prostate gland. Symptoms include frequent urination (particularly at night), hesitancy and impairment of urinary stream. Results of clinical trials indicate that saw palmetto can assist in the relief of symptoms of BPH. The actual mechanisms of action of saw palmetto in BPH are still not clear, but are thought to be due to its ability to reduce inflammation and oedema and reduce smooth muscle spasm. Saw palmetto does not artificially lower PSA levels, hence it is unlikely to mask the presence of prostate cancer.