Benefits
Urinary symptom scores and urine flow in older men
A Cochrane review pooled 18 trials in 1,562 men with an enlarged prostate. Men taking pygeum were about twice as likely as those on placebo to report overall symptom improvement, night-time urination fell by 19% and peak urine flow rose by 23%. The trials were small and short, used varied preparations, and few used validated symptom scales.
Night-time urination and urine left after voiding
In the pooled trials of men with an enlarged prostate, night-time urination fell by about 19% and the urine left in the bladder after voiding by about 24% compared with placebo. Waking at night to urinate has many possible causes, so it should be checked by a doctor rather than assumed to be prostate-related.
Overall urination improvement in a 263-man placebo-controlled trial
In a 60-day double-blind trial at 8 centres, 263 men with an enlarged prostate took 50 mg of pygeum extract twice daily or placebo. Urination improved overall in 66% on pygeum versus 31% on placebo, and the objective urination measures as a group also favoured pygeum. Five men had digestive side effects and three of them stopped.
Once-daily and twice-daily dosing compared
In a 2-month double-blind trial, 209 men took 100 mg once daily or 50 mg twice daily, and both schedules improved IPSS by a similar amount (35 to 38%). Without a placebo group, this shows the two schedules are interchangeable, not how much of the change is due to pygeum.
Mechanism of action
Possible enzyme effects (lab evidence)
Lab studies have suggested weak inhibition of 5-alpha-reductase, the enzyme that converts testosterone to DHT. The human trials did not measure DHT or hormone levels, so the role of this effect in people is unknown.
Anti-inflammatory and growth-factor effects in cells
In cell and animal studies, pygeum extract has reduced inflammatory signalling and slowed the growth of prostate connective-tissue cells stimulated by growth factors. These are lab findings, not results measured in men taking the supplement.
Bladder effects in animals
Animal studies have suggested effects on bladder muscle function and emptying. This remains a possible explanation rather than something shown in men.
Whole extract rather than a single compound
The trials used a lipid-soluble bark extract containing phytosterols, triterpenes and ferulic acid esters. No single compound has been shown to reproduce the effects of the whole extract.
Clinical trials
Cochrane systematic review of randomized trials of pygeum, alone or combined, versus placebo or other treatments (Wilt et al. 2002, Cochrane Database Syst Rev)
1,562 men with symptomatic benign prostatic hyperplasia in 18 trials (mean duration 64 days, range 30 to 122).
Compared with placebo, pygeum gave a moderately large improvement in combined symptom and flow outcomes (effect size -0.8 SD, 6 studies). Men were 2.1 times as likely to report overall improvement; nocturia fell 19%, residual urine 24%, and peak flow rose 23%. Side effects were mild and similar to placebo. Only one trial reported allocation concealment, and none compared pygeum with alpha-blockers or 5-alpha-reductase inhibitors.
Systematic review and quantitative meta-analysis by the same Minneapolis VA group (Ishani et al. 2000, Am J Med)
1,562 men with symptomatic benign prostatic hyperplasia.
Same pooled results as the Cochrane review: about twice the chance of overall symptom improvement, 19% less nocturia, 24% less residual urine and 23% higher peak flow, with mild side effects similar to placebo. The authors concluded pygeum modestly but significantly improves symptoms and flow, while noting short studies and varied preparations and outcome measures.
Double-blind, placebo-controlled 60-day trial of 50 mg pygeum extract twice daily at 8 centres in Germany, France and Austria (Barlet et al. 1990, Wien Klin Wochenschr)
263 men with urination problems due to benign prostatic hyperplasia.
Overall urination improved in 66% on pygeum versus 31% on placebo (p<0.001), and the quantitative measures (residual urine, urine flow and day and night urination frequency) together showed a significantly better treatment response, as did patient-rated symptoms. Five patients had digestive side effects, and three of them stopped treatment.
Randomized, double-blind 2-month comparison of 50 mg twice daily versus 100 mg once daily, followed by a 10-month open extension (Chatelain et al. 1999, Urology)
209 men with symptomatic benign prostatic hyperplasia completed the comparative phase; 174 entered the open phase.
IPSS improved by 38% and 35% and peak flow by 1.63 and 2.02 mL/s in the two groups, with similar safety. At 12 months, IPSS had fallen from 16 to 9. There was no placebo group, so these changes cannot be attributed to pygeum with confidence.