Saw palmetto extracts can vary considerably in quality, according to a recent study published in the Journal of Urology Open Plus.

A total of 28 saw palmetto supplements were tested by a team of researchers at Eurofins Food Chemistry Testing, Inc. for potency and authenticity. It was found that only six of the extracts, and one multi-active product had the appropriate dosages of 320 mg of saw palmetto extract and the minimum 80% fatty acids content which are validated to address inflammation and improve symptoms of benign prostatic hyperplasia (BPH). BPH is a condition nearly all men will experience in their lifetime, with symptoms including increased urination, sudden urgency, weak stream, and disrupted sleep. 

The study included products purchased in stores and on Amazon, including berry powders, extracts, blends, and multi-actives.

Total fatty acid content ranged from 0.796% for one berry powder product, to 89.923% for a lipid extract product. None of the berry powders met the criteria for clinical efficacy, researchers said.

One product, a lipidosterolic extract marketed by Valensa as USPlus, was unique in meeting criteria established in the US Pharmacopoeia monograph for standardized saw palmetto extracts, met the lipid profile for an authentic product, and was found to contain a clinically effective dose of 320 mg of saw palmetto extract.

According to Bilal Chughtai, MD, urologist and lead author of the study, USP monographs are designed for ground saw palmetto berries and extracts, though results can be less reliable if formulas contain significant amounts of lipids from ingredients like pygeum, stinging nettle, beta-sitosterol, or pumpkin seed oil.

Other tests, such as high-performance thin-layer chromatography (HPTLC) can be used as a further test of authenticity and to check for adulterants, noted Leigh Vinocur, MD, MS, FACEP, chief medical officer of Valensa. “The active compound is the complete lipidosterolic extract of Serenoa repens (LSESr) extract which meets the USP monograph for identity, purity, and strength. Authentic LSESr has a bioactive fingerprint which has been shown to have the mechanism of action to lower 5-alpha-reductase activity and inhibit inflammatory mediators. When examining adulterated products, the chemical profile suggests that primarily palm and/or coconut oils are wholly or partially used to try and mimic the USP fatty acid profile. However, they usually fall short in completely meeting the USP monograph.”

“Only concentrated extract of mature saw palmetto berries has been found to inhibit the biological process by which testosterone gets converted to DHT, which leads to benign prostate enlargement,” said Chughtai. “This study not only confirms the rampant variability of saw palmetto products, but also highlights the need for physicians and industry to verify the quality of the supplements they’re recommending to patients and consumers to ensure the best results possible.”

A Decades-Old Problem

The bulk of products failed based on failing identity standards, or falling short of a clinically-established dose, Chughtai told Nutraceuticals World. The variability observed in the present study was relatively consistent with that seen in other comparison studies, including work published by Habib and Wylie (2004), and Perini et al. (2018).

“Given the age of some of these studies, unfortunately this is not a novel issue in the industry,” Chughtai said. “This is why it is important to validate the quality of products and make sure commercially-available products are efficacious. Independent third-party verification is a reliable means to verify ingredient and finished product quality.”

The most surprising result, according to Chughtai, was the fact that two of the berry powder products contained less than one tenth of the amount of fatty acids that should be found in the herb.

“All of the ‘berry blend’ products did not contain the therapeutic amount of fatty acids per dose, regardless of the identity. We had also expected more of the lipid extract products to fully meet the monograph requirements. This means that it is critical to look for products that are verified to meet the quality standard of effectiveness set by USP.”

Valensa’s USPlus is the first and only USP verified ingredient that is a lipidosterolic extract of saw palmetto berry, which requires meeting criteria including a total fatty acid content of 80% at minimum, and a fatty acid profile indicative of authentic Serenoa repens based on the ratios of lauric acid concentration to nine other individual fatty acid concentrations.

“Without studies like this to bring quality issues to light, it’s very difficult for consumers to know if they’re taking a supplement full of ‘sawdust’ that doesn’t do anything or a quality saw palmetto product that promotes your prostate health,” said Stephen Hill, vice president of quality and regulatory of Valensa International. “By understanding the role that high-quality saw palmetto extract can play in men’s health, millions of men can benefit from this safe and natural solution to maintaining prostate health and possibly prevent or delay the need for more serious medical interventions down the line.”

Setting the Standard

According to Vinocur, the unique advantage that helped Valensa achieve its USP verification is full vertical integration of its supply chain. “This allows us to control and monitor the saw palmetto berries from the point of harvest, ensuring only ripe fruit are picked, through the extraction process and packaging of the final product. Every step is documented and reviewed to ensure that the USPlus extract meets the USP requirements and also has the profile for efficacy. Furthermore, our supply chain process and controls allow for traceability which is important to maintain quality standards for USP certification.”

It takes a dedicated quality team in order to achieve both USP and FDA standards for saw palmetto, noted Vinocur, and heavy emphasis needs to be placed not just on the manufacturing side but also on robust quality of raw materials.