Sources

Grass pollen extract tablets for prostate disease are available in pharmacies and health food stores or can be ordered from a number of sources on the Internet.

Therapeutic Dosages

The recommended dosage for grass pollen extract tablets is between 80 and 120 milligrams (mg) per day.²

Therapeutic Uses

Two double-blind, placebo-controlled studies found that grass pollen extract can help reduce symptoms of benign prostate enlargement (technically called benign prostatic hyperplasia, or BPH).^3,4

One small, double-blind study found evidence that a product containing grass pollen, the pistils (seed-bearing parts) of grass, and royal jelly (a product made by bees) may be helpful for PMS.²² Another small double-blind study found benefit with the same combination for treatment of menopausal symptoms.²³

Grass pollen extract has also shown promise for treating prostatitis. In a six-month, double-blind study of 60 men with non-bacterial prostatitis, use of the grass pollen extract was more effective than placebo in relieving symptoms.²⁴

Grass pollen has additionally been investigated for its usefulness in treating (inflammation or infection of the prostate), prostate cancer,^8–10 and high cholesterol.¹¹ Animal studies also suggest that it may protect the liver from damage by some types of poisons.¹² However, the scientific evidence for all of these other proposed uses remains very weak.

What Is the Scientific Evidence for Grass Pollen Extract?

Two double-blind, placebo-controlled studies found that grass pollen extract can improve symptoms of BPH.

In the first double-blind, placebo-controlled study, 103 people with BPH were assigned to take either placebo or 2 capsules of a standardized grass pollen extract 3 times daily for a period of 12 weeks.¹³ At the end of the study, 69% of the participants who had been taking the grass pollen had reduced the number of trips they had to make to the bathroom at night. In the placebo group, only 37% reported improvement in this symptom. The amount of urine remaining in the bladder following urination was reduced in the treatment group by 24 milliliters (ml) and by 4 ml for the placebo group. Both of these were statistically significant improvements for those taking grass pollen.

The second double-blind, placebo-controlled study lasted longer but enrolled fewer participants.¹⁴ Fifty-seven men with prostate enlargement were enrolled in the study, with 31 taking 92 mg of the grass pollen extract daily for 6 months and the remaining 26 taking placebo. As with the previous study, statistically significant improvements in nighttime frequency of urination and emptying of the bladder were found with use of grass pollen extract. Additionally, 69% of the participants receiving treatment reported overall improvement, while only 29% of the group taking the placebo felt they had improved—another statistically significant difference.

An important finding in this study was that, according to ultrasound measurements, prostate size decreased in men taking grass pollen. Not all treatments for BPH can reduce prostate size. It may be that treatments which shrink the prostate can reduce the need for surgery—such is the case, at least, with the prescription drug finasteride. Whether grass pollen offers this same potential benefit is not yet known.

Two additional studies compared grass pollen to other alternative treatments for prostate enlargement, rather than to placebo.^15,16 An open study pitted grass pollen against pygeum.¹⁷ Although pygeum is considered a more established treatment for prostate enlargement, grass pollen appeared to work better. The pollen extract was found to be significantly more effective in improving the flow of urine, emptying of the bladder, and the participants' perceptions of relief. Those in the grass pollen group also had a significant reduction in prostate size while there was no reduction of size in the pygeum group. It appears from this that grass pollen is a more effective treatment than pygeum, but since the study was not blinded, the results are somewhat questionable. (For more information on why double-blind studies are so important, see Why Does This Database Rely on Double-blind Studies?)

A double-blind comparative study pitted grass pollen against an amino acid preparation and found no significant difference between the two.¹⁸ Unfortunately, since we don't know how well the amino acid medication works, the result has little meaning.

No one is certain how the grass pollen extract might cause the beneficial results seen in the studies. One theory is that it inhibits the body's manufacturing of prostaglandins and leukotrienes, which might relieve congestion and act as an anti-inflammatory.¹⁹ This, however, probably would not explain the reduction in prostate size, meaning that there may be more than one mechanism at work.

Safety Issues

No serious side effects have been reported with the use of grass pollen extract. No adverse reactions were observed in any of the clinical trials discussed above, although one review author mentioned rare reports of stomach upset and skin rash.²⁰

Although many people are allergic to grass pollen, the grass pollen products discussed in this article are processed to remove allergenic proteins.²¹ For this reason, it is unlikely that grass-allergic individuals will have an allergic reaction.

Maximum safe doses for young children, pregnant or nursing women, or those with liver or kidney disease are not known.