Although saw palmetto extract has been claimed to be a herbal remedy for benign prostatic hyperplasia, it is an ineffective treatment, and did not affect PSA levels, even when the extract was provided in high doses. However, the Cochrane studies used different extracts. This suggests that the lack of an effect found in the most recent Cochrane review was due to the differences in the saw palmetto extracts used. Permixon was used in a 2016 study. Limited in vitro and animal model studies have investigated potential for use in the treatment of cancer. However, according to the American Cancer Society, "available scientific studies do not support claims that saw palmetto can prevent or treat prostate cancer in humans". Patients interested in taking saw palmetto extract for management of BPH are advised to consult first with a healthcare provider. Beta-sitosterol, a chemical present in saw palmetto extract, is chemically similar to cholesterol. In one trial, high levels of serum sitosterol correlated with increased risk of heart attack. However, a meta-analysis of 17 trials saw no connection between serum sitosterol status and cardiovascular disease.
Precautions and contraindications
Children
The use of saw palmetto extract is not recommended in children under 12 years old because it may affect the metabolism of androgen and estrogen hormones.
Pregnancy and lactation
Saw palmetto extract should not be used during pregnancy. The effects of saw palmetto extract on androgen and estrogen metabolism can potentially impair fetal genital development. Saw palmetto extract should also be avoided during breastfeeding due to a lack of available information.
Surgery and bleeding risk
In a case report, a patient taking saw palmetto extract had increased bleeding time during surgery. Bleeding time returned to normal after stopping taking the herb. One clinical trial pre-treated prostate surgery patients with saw palmetto for five weeks prior to the surgery, because there was evidence from earlier literature that such pre-treatment reduced operative bleeding. The trial reported no improvement compared to placebo. As a general rule surgeons should ask patients to discontinue dietary supplements prior to scheduled surgery.
Interactions
Saw palmetto extract may decrease the effectiveness of estrogen products by reducing estrogen levels in the body via its antiestrogenic effects. It can interfere with the use of birth control pills that contain estrogen as an active ingredient. As a result, it is recommended that an additional form of birth control, such as a condom, be used to prevent pregnancy in patients taking birth control pills with saw palmetto extract. In addition, saw palmetto extract can also interfere with hormone replacement therapy by reducing the effectiveness of estrogen pills. The combination of saw palmetto extract with estrogen products should be used with caution. When used in combination with an anticoagulant or antiplatelet drug, saw palmetto extract can increase the risk of bleeding by enhancing the anticoagulation or antiplatelet effects. Some examples of anticoagulant and antiplatelet drugs include aspirin, clopidogrel, nonsteroidal anti-inflammatory drugs, and warfarin. Therefore, the combination of saw palmetto extract with anticoagulant or antiplatelet drugs should be used with caution.
