Fucoidan from Undaria pinnatifida Shows Promise for Managing BPH Symptoms in Clinical Trial

A randomized, double-blind, placebo-controlled trial published in Research and Reports in Urology examined whether fucoidan derived from the brown seaweed Undaria pinnatifida (UPF) could improve symptoms of benign prostatic hyperplasia (BPH).¹ The 90-day study enrolled 95 men aged 45–80 with clinically and radiologically confirmed moderate BPH, defined by a baseline International Prostate Symptom Score (IPSS) of 8–19. Participants were randomized 1:1 to receive either 1 g/day of UPF (two 500 mg capsules manufactured by Marinova Pty Ltd.) or a matched placebo containing hydroxypropyl methylcellulose. Of the 95 randomized participants, 88 completed the study per protocol, with compliance exceeding 99%.

The study notes that other nutraceutical marketed for BPH intervention include Serenoa repens (Saw Palmetto), Cucurbita pepo (pumpkin), Solanum lycopersicum (tomato) and Urtica dioica (stinging nettle).

Did UPF Improve Prostate Symptom Scores?

The primary endpoint, total IPSS, improved significantly in the UPF group compared to placebo by day 60 (p=0.0234) and further by day 90 (p=0.0015). Mean total IPSS reduction from baseline to day 90 was −3.40 in the UPF group versus −0.93 in the placebo group. Both IPSS voiding (p=0.0006) and storage (p=0.0150) sub-scores improved significantly by day 90, and quality-of-life scores related to urinary symptoms improved significantly at both day 60 and day 90.

Were the Improvements Clinically Meaningful?

The study applied Minimum Clinically Important Difference (MCID) thresholds to assess whether score changes were meaningful to participants. By day 90, 60.0% of UPF participants achieved a ≥2-point IPSS reduction (severity MCID) compared to 42.2% on placebo, and 51.1% achieved a ≥3-point reduction (overall MCID) compared to 28.9% on placebo—a difference that reached statistical significance (p=0.0314).

What About Secondary Outcomes Like Urinary Flow and PSA?

Secondary outcomes told a more mixed story. Urinary flow rate increased more in the UPF group (1.13 mL/s) than placebo (0.09 mL/s), and post-void residual volume decreased in both groups, but neither between-group difference reached statistical significance. Serum PSA levels showed no meaningful change in either group.

What Are the Broader Gut Health Applications?

Separately, Marinova confirmed earlier this year that its Undaria pinnatifida fucoidan extract meets the International Probiotics Association's criteria for a prebiotic.² This validation draws on in vitro gut-simulation research showing that fucoidan supplementation increased butyrate production and microbial diversity.

Was UPF Safe and Well Tolerated?

Of 22 total adverse events reported across both arms, only three were judged potentially product-related, two cases of groin itching in the UPF group and one case of rash in the placebo group, which resolved without complication. Vital signs remained within normal limits throughout the study.

What Are the Limitations, and What's Next?

The authors note several limitations, including the modest sample size and 90-day duration, which restricts conclusions about long-term efficacy. They also caution that observed improvements should be interpreted in the context of a nutraceutical intervention rather than as comparable to established pharmacological therapies such as alpha-blockers or 5-alpha-reductase inhibitors. Larger, multicenter, longer-duration trials are recommended to confirm these findings.

“This was an incredibly rigorous study delivering statistically and clinically significant results,” stated study co-author and Marinova’s Research Director, Barbara Wimmer, PhD.³ “These findings will certainly be of interest to nutraceutical brands targeting men’s health.”

Who Funded the Study?

The trial was funded by Marinova Pty Ltd., which manufactures the UPF ingredient and supplied the investigational product; two of the six authors were Marinova employees at the time of the study, while others were affiliated with the contract research organization that managed trial conduct.

References

1. Wimmer BC, Dwan CA, Bhalerao SS, Gupta CG, Vaze SV, Kshirsagar SS. Fucoidan from Undaria pinnatifida Improves Benign Prostatic Hyperplasia Symptoms in Men: A Randomized, Double-Blind, Placebo-Controlled Study. Res Rep Urol. 2026;18:1-16. doi:10.2147/RRU.S597883
2. McEvoy E. New Research Highlights Marinova’s Fucoidan as a Prebiotic for Microbiome and Gut Health Support. April 22, 2026. Accessed July 27, 2026. https://www.nutritionaloutlook.com/view/new-research-highlights-marinova-s-fucoidan-as-a-prebiotic-for-microbiome-and-gut-health-support
3. Marinova. Men’s health: Breakthrough clinical trial. July 22, 2026. Accessed July 27, 2026. Press release provided via email.