Clinical trial
A double-blind, placebo-controlled clinical study was designed to assess the effects of Undaria pinnatifida fucoidan, produced by Marinova, on the symptoms of BPH.
The study recruited men aged 45-80 years with clinically and radiologically confirmed moderate BPH.
Half of the participants were administered high purity Undaria pinnatifida fucoidan. The other half were administered a placebo.
The 90-day study utilised a validated assessment tool, the International Prostate Symptom Score (IPSS), to assess changes in BPH symptoms. It also determined if these changes were clinically significant. As part of the IPSS, the study included a quality-of-life assessment based on urinary symptoms.
Key findings
The study showed that fucoidan supplementation resulted in:
- Statistically and clinically significant improvements in BPH symptoms.
- Significant improvement in total IPSS scores at day 60, further improving at day 90. The difference between the fucoidan and placebo groups remained statistically significant through to the end of the study.
- Both voiding and storage composite scores improving significantly at day 90, including a more than nine-fold improvement in voiding symptoms and a two-fold improvement in storage symptoms compared to the placebo.
- Improvements in individual symptoms, including straining, emptying, frequency and intermittency at day 90.
- Quality-of-life related to urinary symptoms improving significantly and continuously throughout the study. The placebo group showed no change in the quality-of-life score.
The fucoidan supplement was well tolerated and shown to be safe throughout the study period.
Levels of Prostate-Specific Antigen (PSA) remained within normal ranges, suggesting fucoidan supplementation will not interfere with routine prostate health monitoring.
The full paper, ‘Fucoidan from Undaria pinnatifida improves benign prostatic hyperplasia symptoms in men: A randomized, double-blind, placebo-controlled study', was published in the journal Research and Reports in Urology.
An overview of the study is presented in the short video below.
A previous in vivo study showed that Undaria pinnatifida fucoidan, produced by Marinova, effectively reduced the expression of dihydrotestosterone, PSA levels, IL-β, TNF-α, and prostate weight. It also preserved the morphology of the prostate tissue through mechanisms involving anti-inflammation, downregulation of dihydrotestosterone, and pro-apoptotic activity in an animal model (Shanmugasundaram, 2024).
The gut-prostate axis is an emerging field of research. A separate in vitro study showed that the same Undaria pinnatifida fucoidan extract increased the production of the short-chain fatty acid butyrate (Wimmer, 2025). Butyrate has been extensively studied for its anti-inflammatory effects. Its production may positively impact BPH by reducing prostate inflammation and inhibiting cell growth.