Skip to main content


Studies in Men with Enlarged Prostates:

The most current systematic reviews and meta-analyses of the effects of flower pollen on the symptoms of an enlarged prostate (aka benign prostatic hyperplasia) identified 4 randomized, controlled trials (1,2,3,4).  Two of these trials compared the effect of flower pollen extracts to other natural supplements (Paraprost and African plum plant) (5,6).  These other supplements are not, however, generally accepted as valid controls for clinical trials for benign prostatic hyperplasia.

The two remaining trials were both double-blinded and placebo-controlled.  They lasted between 12 and 24 weeks and included a combined total of 163 men.  One of these studies reported a significant improvement in self-rated urinary symptom scores relative to placebo, but they did not use a validated urinary symptom-scale score (i.e. International Prostate Symptom Score).  The other study didn’t record self-rated urinary symptoms.  Both placebo-controlled studies did, however, record peak urine flow, residual urine volume, and some measure of nocturia (urination at night).  While there was no significant difference between placebo and pollen treated groups in residual urine volume, pollen treated groups did show significant comparative improvements in peak urine flow and nocturia (7,8).  Overall, two times as many men reported improvements in nocturia in the pollen treatment group as reported improvements in the placebo group (1).  According to the authors of the systematic reviews and meta-analyses, these results suggest that flower pollen extract has a modest beneficial effect on some of the symptoms of an enlarged prostate.  The authors were also quick to point out, however, that there are significant limitations to the current evidence.  There are currently very few studies, and all of them are ‘underpowered’.  Some of the existing studies also failed to report dosages or standardization of the extracts, and to use validated measurements (i.e. urinary symptom score surveys) (1,2,3,4).  More ‘high-powered’, well-designed; randomized, double-blind, controlled trials are needed to confirm the benefits of flower pollen extract on men with benign prostatic hyperplasia.

Studies in Men with Prostatitis:

Most of the 21st century clinical trials on flower pollen extract have investigated its effect on chronic prostatitis and/or chronic pelvic pain syndrome.  Two of these trials were randomized, double-blind, and placebo-controlled (9,10).  Both also had special control measures in place to ensure that their participants did not have bacterial prostatitis.  The smaller of the two trials (58 participants) lasted for 6 months and recorded data on pain, urinary voiding symptoms, urinary storage symptoms, and sex-related symptoms.  Men who received the pollen extract had significantly lower pain scores, less voiding symptoms, and less storage symptoms at the conclusion of the study than those who received placebo.  Subjective, but blinded, evaluation of the patients also revealed that 22 of the 30 men from the pollen treatment group were ‘cured’ or ‘clinically improved’ while only 10 out of 28 of the placebo group were considered ‘clinically improved’.  The authors concluded that these results indicate that pollen extract is significantly more efficacious at reducing symptoms of chronic prostatitis than placebo.  It should be noted, however, that the symptom survey used in this study was not the validated NIH Chronic Prostatitis Symptom Index and the methods/criteria for the subjective evaluations were not disclosed (9).

The second placebo-controlled study involved 139 men and lasted for 12 weeks.  This study did use the NIH Chronic Prostatitis Symptom Index and saw significant improvement in the pollen treatment group compared to placebo for overall scores and subdomain scores relating to pain and quality of life.  No significant improvement relative to placebo was seen in scores relating to urinary symptoms.  Changes in residual urine volume, validated urinary symptom scores (IPSS), and sexual domain of life questionnaires were also comparable between pollen treatment and placebo groups.  The significant improvements in chronic prostatitis/chronic pelvic pain syndrome scores seen in this study were mainly the result of the effect of pollen extract on pain symptoms (10).

More ‘higher-powered’, randomized, double-blinded, placebo-controlled trials are needed to confirm that pollen extract actually improves pain symptoms relating to chronic prostatitis.  More research is also needed to determine optimum dosage of flower pollen extract and whether different formulations or flower sources impacts its efficacy.


  1. Wilt TJ, Ishani A, Rutks I, MacDonald R. Phytotherapy for benign prostatic hyperplasia. Pub Health Nutr. 2000;3(4A):459-472. doi:10.1017/S1368980000000549.
  2. MacDonald R, Ishani A, Rutks I, Wilt TJ. A systematic review of Cernilton for the treatment of benign prostatic hyperplasia. BJU Int. 2000;85(7):836-841. doi.10.1046/j.1464-410×2000.00365.x.
  3. Wilt T, MacDonald R, Ishani A, Rutks I, Stark G. Cernilton for benign prostatic hyperplasia. Cochrane Database of Sys Rev. 2011;11(5):CD001042. doi:10.1002/14651858.CD001042.pub2.
  4. McNicholas T and Kirby R. Benign prostatic hyperplasia and male lower urinary tract symptoms (LUTS). BMJ Clin Evid. 2011;1801.
  5. Dutkiewicz S. Usefulness of Cernilton in the treatment of benign prostatic hyperplasia. Int Urol Nephrol. 1996;28(1)49-53.
  6. Maekawa M, Kishimoto T, Yasumoto R, et al. Clinical evaluation of Cernilton on benign prostatic hypertrophy: a multiple center double‐blind study with Paraprost. Hinyo Kiyo. 1990;36(4):495-516.
  7. Becker H and Ebeling L. Konservative therapie der benignen prostata‐hyperplasie (BPH) mit Cernilton®N: ergebnisse einer plazebokontrollierten doppleblindstudie. Urologe B. 1988;28:301-306.
  8. Buck AC, Cox R, Rees RWM, Ebeling L, John A. Treatment of outflow tract obstruction due to benign prostatic hyperplasia with the pollen‐extract, Cernilton: a double‐blind, placebo‐controlled study. Br J Urol. 1990;66:398-404.
  9. Elist J. Effects of pollen extract preparation Prostat/Potit on lower urinary tract symptoms in patients with chronic nonbacterial prostatitis/chronic pelvic pain syndrome: a randomized, double-blind, placebo-controlled study. Urology. 2006;67(1):60-63. doi:10.1016/j.urology.2005.07.035.
  10. Wagenlehner F, Schneider H, Ludwig M, Schnitker J, Brahler E, Weidner W. A pollen extract (Cernilton) in patients with inflammatory chronic prostatitis-chronic pelvic pain syndrome: a multicenter, randomized, prospective, double-blind, placebo-controlled phase 3 study. Eur Urol. 2009;56(3):544-551. doi:10.1016/eururo.2009.05.046.