Pollen Extract for Prostatitis

Rye grass pollen extract probably eases the pain of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), though the effect is modest. In a multicentre double-blind trial, 139 men with the inflammatory form (NIH category IIIA) took two capsules every 8 hours or placebo for 12 weeks. Pain, quality of life and total symptom scores improved significantly more on the extract, and 70.6% responded compared with 50.0% on placebo (p=0.0141) [1]. A smaller placebo-controlled trial of 60 men with long-standing symptoms also favoured the extract [2].

Trials against other treatments add support: pollen extract with vitamins beat ibuprofen over 4 weeks [3], and added to an alpha-blocker, rye grass extract eased pelvic pain more than tadalafil [4]. A 2017 meta-analysis of four randomised trials (384 men) found better quality of life [5], and the American Urological Association's 2025 guideline says clinicians may prescribe pollen extract (a conditional recommendation, Grade B evidence) [6]. A Cochrane review rated the evidence for plant-based treatments as a group as low quality [7].

Preclinical studies report anti-inflammatory and anti-proliferative effects of pollen extract [5]. In one trial in men with CP/CPPS, pollen extract with vitamins lowered seminal levels of the inflammatory messenger interleukin-8 (IL-8) from 878 to 298 pg/mL over 3 months, alongside symptom improvement [8].

The anti-inflammatory findings come mainly from preclinical work [5], and the IL-8 result comes from a combination of pollen extract and vitamins compared with bromelain, so it can't be credited to the extract alone [8]. The European Association of Urology's guideline notes that the benefit in the main trial was mainly on pain [9]: the measurable effect is symptom relief, not proof that inflammation in the prostate is cleared.

The placebo-controlled trial used two capsules of the extract every 8 hours (six a day) for 12 weeks; the abstract does not give the capsule strength [1]. Other trials used two capsules every 8 hours for 8 weeks [10], four capsules a day added to an alpha-blocker for 12 weeks [4], and one tablet three times a day for 6 months [11]. A combination product with vitamins was taken as two capsules once a day [3].

Because products and strengths differ, follow the label of a rye grass pollen extract and judge the effect at about 12 weeks, the length of the main trial.

In the largest trial, 139 men with inflammatory CP/CPPS were randomised to rye grass pollen extract (70) or placebo (69) for 12 weeks. The primary outcome, pain on the NIH Chronic Prostatitis Symptom Index (NIH-CPSI), improved significantly more on the extract (p=0.0086), as did quality of life (p=0.0250) and the total score (p=0.0126). A response, meaning a fall in total score of at least 25% or 6 points, was seen in 70.6% compared with 50.0% (p=0.0141), and adverse events were minor [1].

An earlier double-blind trial randomised 60 men aged 20 to 55, whose symptoms had lasted over 6 months without responding to other treatment, to a pollen extract preparation or placebo for 6 months. More men on the extract were rated cured or improved, with no adverse reactions, though the abstract gives no figures [2].

Against ibuprofen 600 mg three times a day, pollen extract with vitamins produced a fall in NIH-CPSI total score of 25% or more in 75.6% compared with 41.3% of 87 men after 4 weeks (P=0.002), with fewer adverse events [3]. Against bromelain for 3 months, 24 of 32 men on pollen extract with vitamins and 8 of 33 on bromelain had a significant score reduction (p<0.001) [8].

In 100 men whose pain persisted despite an alpha-blocker, adding rye grass extract improved the total score more than adding tadalafil 5 mg (-6.8 vs -4.6 points; P=.02) and the pain score more (-4.1 vs -1.5; P<.001), while tadalafil did better for urinary symptoms [4]. In a Japanese trial of 100 men, the extract and another plant-based drug, Eviprostat, performed similarly, with response rates of 78.1% and 88.2% [10].

A 2017 systematic review counted six uncontrolled studies (206 men, mean response rate 83.6%) and four randomised trials (384 men). Pooling the trials showed better quality of life on the extract (odds ratio 0.52, 95% CI 0.34 to 0.81) and no significant adverse events [5]. A Cochrane review of drug treatments found that plant-based treatments as a group may reduce symptoms compared with placebo (NIH-CPSI mean difference -5.02 points), but rated the evidence low quality; it treated a 25% or 6-point fall as the smallest change that matters to patients [7].

The AUA's 2025 guideline lists pollen extract with saw palmetto and quercetin as phytotherapies clinicians may prescribe to improve pain, voiding symptoms and quality of life [6]. The European guideline describes the placebo-controlled trial as adequately powered, with clinically significant symptom improvement over 12 weeks [9].

For an enlarged prostate (BPH), a different condition, a review of four short trials (444 men) found modest gains in self-rated urinary symptoms and night-time urination but no change in urine flow, residual volume or prostate size [12].

There is no single standard treatment for CP/CPPS. The European guideline recommends multimodal treatment matched to each man's symptoms, alpha-blockers for men whose symptoms began less than a year ago, antibiotics for at least six weeks in untreated men within that first year, and anti-inflammatories with attention to long-term side effects [9]. A network meta-analysis of oral drugs concluded that pharmacological treatments overall have little evidence supporting efficacy [13].

Pollen extract is best seen as one of these modest options, used alongside a urologist's plan rather than instead of it. The other phytotherapies the AUA names are quercetin and saw palmetto.

The trials lasted 4 weeks to 6 months [3][2], and the 2017 review called for more robust randomised trials with longer follow-up [5]. Products varied, from rye grass extract alone to combinations with vitamins, and several trials and the review came from the same research group. The placebo-controlled trial enrolled only the inflammatory subtype, so its result may not apply to men without signs of inflammation [1].

Pollen extract has been well tolerated in prostatitis trials. Adverse events were minor in the 139-man placebo-controlled trial [1], no adverse reactions were found in the 60-man trial [2], 97% of men tolerated it over 6 months in an early study [11], and the 2017 review found no significant adverse events [5]. In BPH trials, 4.8% of men stopped the extract compared with 2.7% on placebo [12].

Longer-term data come from an uncontrolled study in which 28 men took it for over a year, with no adverse reactions reported [14]. None of the trials reported results separately for men with pollen allergies.

We found no interaction studies of pollen extract with medicines. In one trial rye grass extract was added to ongoing alpha-blocker treatment [4]; the abstract does not report safety outcomes for the combination.