Contamination, Substitution & Adulteration

If someone feels seriously unwell after taking a supplement, call 911 (US) for an emergency or Poison Help at 1-800-222-1222 (US), and bring the bottle. Other countries are listed on poison help by country. To report a product problem in the US, see how to report a side effect.

Three problems are easy to mix up. In plain terms:

• Contamination: something unwanted gets in, such as a metal, a mold or another plant.
• Substitution: a different plant is used in place of the one on the label.
• Adulteration: something is added or swapped on purpose, for example a cheaper plant or an unlisted drug.

A 2013 study describes herbal products as sometimes "contaminated or substituted with alternative plant species and fillers" not on the label. [1] This page lists what studies of adaptogen-related products found. They are small, were done in different countries and years, and tested particular products, so they cannot tell you how common each problem is overall. This library does not name or endorse products.

What the US system says

The FDA does not approve dietary supplements for safety and effectiveness, or approve their labeling, before they are sold, and companies are responsible for meeting safety standards. [2] NIH says manufacturers must ensure products do not contain contaminants or impurities, but the rules are less strict than for medicines. [3]

Studies of wrong or extra plants

Two pairs of plant names help explain these findings. Rhodiola rosea is the species products claim, and R. crenulata is a related species that the 2016 authors describe as believed to be a common adulterant. [5][9] Panax ginseng (Asian ginseng) and P. quinquefolius (American ginseng) have similar components and look alike but are known to have different medicinal values, and a 2020 study developed genetic markers to tell them apart. [10]

Ginseng: variation and detection

A 2004 analysis of ginseng supplements from nine manufacturers found total ginsenosides ranged from 5.3 to 18.2 mg per serving, and ginseng and echinacea were the most variable of five botanicals. [11] That is variation in content, not proof of adulteration. Separately, laboratory papers show how substitution can be detected: a 2026 microscopy and chemistry study found that two common adulterant roots, Codonopsis pilosula and Platycodon grandiflorus, lacked the ginsenosides found in Panax species. [12] A 2024 spectroscopy study tested ginseng powder adulterated with arrowroot, bellflower and lance asiabell. [13] These method papers show that adulteration is possible and detectable. They do not measure how often it happens in stores.

Heavy metals

• A 2004 study of Ayurvedic products made in South Asia and sold in the Boston area found 14 of 70 (20%) contained lead, mercury or arsenic, and each of those could exceed published standards if taken as the maker recommended. [14] These were Ayurvedic products in general, not a survey of adaptogens.
• NIH's page on Ayurvedic medicine says some Ayurvedic preparations may contain lead, mercury or arsenic in amounts that can be toxic. [15]
• A 2011 study tested four single dried herbs from local markets, including Withania somnifera and amla, for four metals and pesticide residues and found all below detection limits. [16] That is four samples from one setting.
• Plants and mushrooms can concentrate metals from soil and water. [17]

Proper evidence not found: we searched PubMed for large surveys of heavy metals or pesticide residues specifically in finished ashwagandha, ginseng, rhodiola or holy basil supplements and found no study we could cite. Not finding one does not mean the products are free of these problems.

Unlisted drugs

NIH says some products promoted mainly for weight loss, sexual enhancement and bodybuilding may contain prescription drugs not allowed in supplements, or ingredients not on the label. [3] A 2017 review found undeclared erectile-dysfunction drugs and the weight-loss drug sibutramine in herbal products of those types. [18] These reports are not about adaptogens as a group, and whether any adaptogen-labeled product has been affected is not described in the sources we read.

Why it matters for safety

A different plant can mean different cautions. NIH notes that supplements may interact with medicines, and "natural" does not always mean "safe." [3] The 2013 authors said some contaminants they found pose serious health risks. [1]

What a reader can do

• Check the scientific name and plant part on the label (reading an adaptogen label).
• Look for details of independent testing, and see what it can and cannot show (testing and certificates of analysis).
• Keep the bottle and lot number, and report problems.
• Ask a pharmacist or clinician before combining a supplement with medicines, in pregnancy or breastfeeding, with liver, kidney or thyroid conditions, or before surgery.
• More general guides: adulteration, substitution and mislabeling and heavy metals in supplements.