‘Extremely disappointing’: NOW’s testing of SAM-e brands highlights persistent quality problems

Dietary supplement capsules
Illinois-based NOW tested 24 SAM-e supplements from Amazon internally and externally at Eurofins labs. (Getty Images)

Natural product manufacturer NOW reports that that “profound quality and labeling failings continue” after its latest round of dietary supplement testing found that 20 of 24 SAM-e samples purchased on Amazon failed potency tests.

This is the second time the Bloomingdale, IL-based company has analyzed SAM-e dietary supplements after its March 2020 testing revealed that all 11 products tested were of low potency, and two of those were found to contain none of the active ingredient whatsoever.

SAM-e, or S-Adenosyl methionine, is an endogenous molecule that is involved in the formation, activation, or breakdown of other chemicals in the body, including hormones, proteins, phospholipids. While classified as a drug in some countries, it has been sold as a dietary supplement in the United States for more than two decades. It has been used for mood support and to support consumers suffering from chronic inflammatory conditions such as fibromyalgia or osteoarthritis.

In addition to NOW’s 2020 testing, a lawsuit was filed in 2019 against several similar brands of SAM-e due to low potency, but that was eventually dismissed.

New data

NOW decided to revisit SAM-e category, and to purchase a new round of samples from more brands and see if any brands corrected their false labeling claims.

In October 2024, the company purchased two bottles each of 24 “suspicious” SAM-e supplements on Amazon to test internally and externally at Eurofins labs. They were deemed suspicious because they appeared to be mislabeled based on excessively high potency claims. Also, the product is expensive, and brands appear to cheat regularly with costly products such as SAM-e, explained NOW in a release

Among the samples selected were several in the gummy format because SAM-e is unstable and can degrade quickly due to moisture and heat.

NOW explained that, because of the stability issues, SAM-e is often enteric-coated. Ingredient supplier Gnosis by Lesaffre also makes a proprietary SAM-e from disulfate tosylate salt that is stable enough to avoid enteric coating.

“SAM-e potency is somewhat confusing to understand,” stated NOW. “It takes a minimum of 800 mg of S-Adenosyl L-Methionine Tosylate Disulfate to produce 400 mg SAM-e (S-Adenosyl L-Methionine). Some brands label full disclosure to include this, while others do not. It is not required but does help consumers fully understand what is in the product.”

Low potency

All samples were tested by High-Performance Liquid Chromatography (HPLC) at both NOW’s and Eurofins’ labs using a validated method for testing SAM-e based on the USP monograph for SAM-e.

Comparing their new data with the 2020 test results, NOW reports that five repeat low-potency brands that continue to be sold on Amazon, with one of these brands containing zero potency and three containing less than 20% of label claim.

NOW also included its own product in the analysis and found that the SAM-e content averaged 109% of the label claims. The company said it adds “significant overages to ensure full potency at expiration date.”

Results from both in-house tests and Eurofins for the other 23 products tested showed that 20 failed potency testing, and with 16 of these containing less than 20% of labeled potency.

“Six brands contained ZERO potency at all, including both Gummy products,” said the company.

NOW noted that 48% of failing samples were found in Florida-based brands with some sharing matching or near-identical lot numbers.

NutraIngredients-USA contacted Amazon for a response, but no comment had been received prior to publication.

For a full list of the brands tested and the reported results, please click HERE.

“Product quality and integrity is more important than ever”

Loren Israelsen, president and founder of the United Natural Products Alliance (UNPA), described the results as “extremely disappointing”.

“We fully support NOW’s work to give us a continuing idea of the level of non-compliant products on Amazon,” he added. NOW is a member of UNPA.

Israelsen noted that the news is “particularly unhelpful at this moment where the incoming administration’s nominations for key positions such as Secretary of HHS, Medicare/Medicaid, and even FDA Commissioner, will bring great attention to dietary supplements and natural health approaches, given the nominees' very public and positive views on these subjects.

“It goes without saying that product quality and integrity is more important than ever, given the emerging political dynamics,” he added.

Testing

This is the company’s 19th round of product policing since it initiated its testing program in 2017 to evaluate lesser-known brands sold online. All rounds to date have raised concerns tied to issues such as potency, labeling, contamination, adulteration and heavy metals across product categories.

NOW said it openly shares its results with Amazon and the FDA “hoping they will take action to stop these practices”, and with consumers so they can make informed purchases.

NOW’s ongoing efforts to publicize quality concerns about supplements purchased on Amazon were recognized by NutraIngredients-USA with the 2021 NutraIngredients-USA Award for Industry Initiative of the Year.