If you're a man and you live long enough, you will almost certainly develop benign prostatic hyperplasia (BPH). Ninety percent of all men show signs of such prostatic enlargement by the age of 80. Symptoms include difficulty in starting urination, a diminished force of urinary stream, a sensation of fullness in the bladder after urination, and the need to urinate many times at night. Ultimately, the obstruction can become so severe that urination is impossible.

The most common treatment for BPH is surgery that removes most of the prostate gland. Medications such as Cardura, Flomax, Hytrin, and Proscar can relieve symptoms of BPH. In addition, Proscar has been shown to shrink the prostate and reduce the need for surgery. However, all of these medications can cause significant side effects.

Principal Proposed Natural Treatments

Men who suspect they may suffer from BPH should make sure to see a physician to rule out prostate cancer. After this has been done, many natural options are available that have good scientific backing. Indeed, there are few other conditions for which so many natural therapies have good supporting evidence for efficacy. However, there is one potential advantage for standard medications: some have been shown sufficiently effective at slowing the progression of BPH to help men avoid surgery, while this has not been shown to be true of any natural options.60

The best-documented herbal treatment for BPH is the oil of the berry of the saw palmetto tree. This herb is so well accepted in Europe that synthetic pharmaceuticals are considered alternative therapy for BPH. Saw palmetto offers two potential advantages over conventional drug treatment. The most obvious is that it usually causes no side effects. Another advantage is that saw palmetto does not change protein-specific antigen (PSA) levels. Lab tests that measure PSA are used to screen for prostate cancer. The widely used drug Proscar can artificially lower PSA levels, which may have the unintended effect of masking prostate cancer.

Despite its popularity, the scientific evidence that saw palmetto is effective for prostate enlargement is inconsistent at best.

At least 10 double-blind, placebo-controlled studies involving a total of about 900 participants have compared the benefits of saw palmetto against placebo over a period of 1 to 12 months.2-8,58,61-62 In all but 3 of these studies, the herb significantly improved urinary flow rate and most other measures of prostate disease. However, in the most recent and perhaps best-designed of these studies, a 1-year trial of 225 men, saw palmetto failed to prove more effective than placebo.63 Furthermore, a large review of 14 trials with 5,222 men found that saw palmetto did not improve urinary symptom scores or peak urine flow compared to placebo. Subjects taking saw palmetto reported more overall symptom improvement than those taking placebo, but this result is questionable due to a lack of consistency among the studies.71 Adding to the unsupported evidence, a more recent well designed, placebo-controlled trial involving 369 men found that saw palmetto even at high doses (three times the standard dose) did not improve urinary flow rate compared to placebo.72

A double-blind study followed 1,098 men who received either saw palmetto or the drug Proscar over a period of 6 months.9 According to the results, the two treatments were about equally successful at reducing noticeable symptoms, and neither produced much in the way of side effects. However, Proscar lowered PSA levels, presenting a risk of masking prostate cancer. Saw palmetto did not cause this problem. On the other hand, careful measurements showed that Proscar caused men's prostates to shrink by 18%, while saw palmetto only caused a 6% decrease in size. Although prostate size does not correlate well with severity of symptoms, such a decrease in size might indicate a reduced likelihood of need for surgery. This is a potential advantage for the drug.

A 52-week, double-blind study of 811 men compared saw palmetto to a standard drug for BPH in another class: the alpha-blocker tamsulosin.10 Once again, both treatments proved equally effective. However, saw palmetto caused fewer side effects than the drug. In addition, the herb caused some prostate shrinkage, while the drug allowed a slight prostate enlargement.

Although there are many theories about how saw palmetto works, none have been conclusively established. The best evidence suggests that the herb affects male hormones.

For important dosage and safety information, see the full Saw Palmetto article.

The pygeum tree is a tall evergreen native to central and southern Africa. Its bark has been used since ancient times for urinary problems.

At least 17 double-blind trials, ranging in length from 45 to 90 days, of pygeum for BPH have been performed, involving a total of almost 1,000 individuals.18-22,57 Many of these studies were poorly reported and/or designed. Nonetheless, overall, the results do suggest that pygeum can reduce symptoms such as nighttime urination, urinary frequency, and residual urine volume.

The best of these trials was conducted at 8 sites in Europe and included 263 men between 50 to 85 years of age.23 Participants received 50 mg of a pygeum extract or placebo twice daily. The results showed significant improvements in various measures of BPH severity.

We don't really know how pygeum works. Unlike the standard drug finasteride, it does not appear to work by affecting the conversion of testosterone to dihydrotestosterone.24 Rather, it is thought to reduce inflammation in the prostate and to inhibit prostate growth factors, substances implicated in inappropriate prostate enlargement.25,26,27 We don't know whether pygeum can reduce the need for prostate surgery or whether it affects PSA levels.

For more information, including dosage and safety issues, see the full Pygeum article.

Anyone who lives in a locale where nettle grows wild will likely discover the powers of this dark green plant. Depending on the species, the fine hairs on its leaves and stem cause burning pain that lasts from hours to weeks. Both its leaves and roots can be used as medicine. The root is a popular European treatment for BPH. However, it has not been as well studied as saw palmetto or pygeum.

In a double-blind, placebo-controlled study performed in Iran, 558 people were given either placebo or nettle root for 6 months.64 The results indicated that nettle root is significantly more effective than placebo on all major measures of BPH severity. Benefits were seen in three other double-blind studies as well, enrolling a total of more than 150 men.32-34

For more information, including dosage and safety issues, see the full Nettle article.

Numerous plants contain cholesterol-like compounds called sitosterols and their close relatives sitosterolins. A special mixture of these, called beta-sitosterol, is used for the treatment of BPH.

A review of the literature, published in 1999, found a total of four randomized double-blind, placebo-controlled studies on beta-sitosterol for BPH, enrolling a total of 519 men.37-40 All but one of these studies found significant benefits in both perceived symptoms and objective measurements, such as urine flow rate. The largest trial followed 200 men with BPH for a period of 6 months.41 After the study was completed, many of the participants were followed for an additional year, during which the benefits continued.42 Similar results were seen in a 6-month, double-blind trial of 177 individuals with BPH.43

For more information, including dosage and safety issues, see the full Beta-sitosterol article.

Grass pollen is also used to treat BPH. The grasses used for this preparation are 92% rye, 5% timothy, and 3% corn. Related grass pollen extracts are used for allergy shots. However, the grass pollen extracts described here are different in that they have their allergenic components removed. Grass pollen is also an entirely different product than bee pollen.

Two double-blind, placebo-controlled studies found that grass pollen extract can improve symptoms of prostate enlargement.45,46 There have also been open studies that compared grass pollen to different treatments for BPH.47,48

In the first double-blind, placebo-controlled study, 103 individuals 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.49 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 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.50 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 the prostates of the men taking grass pollen significantly decreased in size according to ultrasound measurements taken.

No one is certain how the grass pollen extract causes the beneficial results seen in the studies. One theory is that it inhibits the body's manufacturing of prostaglandins and leukotrienes, which might relieve prostate congestion by reducing inflammation.51

For more information, including dosage and safety issues, see the full Grass Pollen Extract article.

A 48-week, double-blind trial of 543 men with early BPH compared combined saw palmetto and nettle root against Proscar and found equal benefits.55 The same combination proved superior to placebo in a 24-week, double-blind study of 257 men.65

In a 3-month, double-blind, placebo-controlled study of 144 men with BPS, use of a combination product containing saw palmetto, grass pollen extract, beta-sitosterol, and vitamin E significantly reduced symptoms.59

A 6-month, double-blind, placebo-controlled trial of 44 men given a saw palmetto herbal blend (containing, in addition, nettle root and pumpkin seed oil) found shrinkage in prostate tissue.56 No significant improvement in symptoms was seen, but the authors pointed out that the study size was too small to statistically detect such improvements if they did occur. Another small study failed to find significant benefit with a combination of pygeum and nettle root.66

Other Proposed Natural Treatments

One study provides weak evidence that green tea extracts taken orally might reduce symptoms of BPH.67

Pumpkin seeds are approved for use in BPH by Germany's Commission E. The mineral zinc is also commonly recommended in both Europe and the United States as a treatment for prostate disease, as are both whole flaxseed and flaxseed oil, along with the herbs maca ( Lepidium meyenii) and oat straw ( Avena sativa). However, there is no meaningful evidence to indicate that any of these proposed options are effective.

In large study investigating the influence of dietary patterns and supplement use on the risk of BPH, researchers followed 4,770 men, initially with normal-sized prostates, for 7 years. They found that antioxidants supplements did not significantly reduce BPH risk and that lycopene, zinc, and vitamin D supplementation had only a modest beneficial effect.69

In a 12-month, double-blind, placebo-controlled study of 136 men with benign prostatic hyperplasia of moderate severity, use of Bixa orellana (annatto) at a dose of 250 mg 3 times daily failed to improve symptoms.68

In a preliminary, double-blind trial of 78 older men, flaxseed extract modestly improved the urinary symptoms associated with benign prostatic hyperplasia (prostate enlargement) after four months of treatment.70