Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. These microbes are commonly found in fermented foods, such as yogurt, but are also widely sold as dietary supplements. The U.S. Food and Drug Administration (FDA) generally does not “approve” the vast majority of these products sold on the market. This is because the FDA regulates probiotics based on their intended use, which places most into a category that does not require pre-market approval.
The Regulatory Distinction Between Supplements and Drugs
The question of approval hinges entirely on how a product is classified under the Federal Food, Drug, and Cosmetic Act (FD&C Act). The FDA classifies products containing live microorganisms, including probiotics, primarily as either a dietary supplement or a drug. This distinction is based on the manufacturer’s stated intention, often conveyed through labeling and marketing claims.
A product is classified as a drug if it is intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease. Drugs must undergo a rigorous, multi-stage approval process requiring extensive clinical trials to prove safety and effectiveness for the specific intended use.
In contrast, a product is considered a dietary supplement if it is intended to supplement the diet and is not marketed to treat or prevent a disease. Most probiotics are marketed as supplements, meaning they are not subject to the same pre-market approval requirements as drugs.
Manufacturers of supplements can make “structure/function claims” about how the product affects the body, such as “supports digestive health.” They are legally prohibited from claiming the product treats or prevents a specific disease unless they go through the formal drug approval pathway.
Oversight for Dietary Supplements
Since most probiotics are sold as dietary supplements, their oversight is governed by the Dietary Supplement Health and Education Act (DSHEA) of 1994. Under this framework, the responsibility for ensuring a product is safe and accurately labeled falls primarily on the manufacturer before marketing. Manufacturers do not need to provide the FDA with evidence of safety or efficacy before selling.
To maintain quality and safety, manufacturers must comply with Current Good Manufacturing Practices (CGMPs). These regulations govern the processes, facilities, and controls used in supplement production. CGMPs ensure the product is consistently produced and meets quality standards, including label accuracy regarding ingredient identity and potency.
The FDA’s role is largely reactive, stepping in to take action against a product only after it is on the market if it is found to be unsafe or if its claims are false or misleading.
Many probiotic ingredients also go through the Generally Recognized as Safe (GRAS) notification process, a regulatory designation for food ingredients. GRAS status means that qualified experts agree that the substance is safe for its intended use in food. This system means that a probiotic supplement is presumed safe based on the manufacturer’s data and manufacturing controls, but it lacks a pre-market guarantee of effectiveness from the FDA.
Probiotics as Investigational New Drugs
Probiotics enter the rigorous drug approval pathway when they are intended to treat or prevent a disease, classifying them as live biotherapeutic products. To study a probiotic for a disease indication, researchers must first file an Investigational New Drug (IND) application with the FDA. This IND application allows the unapproved product to be tested in human clinical trials to gather data on safety and efficacy.
If the clinical trials successfully demonstrate that the probiotic is safe and effective for its intended use, the company can then submit a Biologics License Application (BLA) for full market approval. The BLA process is the final step for a biological product, such as a live microorganism, to be officially approved as a drug by the FDA. This drug development path ensures that a live biotherapeutic product meets the same stringent standards for quality, safety, and effectiveness as any other prescription medication.
How Consumers Assess Quality
Given the limited pre-market oversight for most supplements, consumers must look for specific quality markers to ensure they are purchasing a reliable product.
Strain Specificity
The most important detail is strain specificity, which involves looking for the full taxonomic designation printed on the label. The label should list the genus, species, and a specific strain identifier. Benefits are often strain-dependent and not shared across an entire species.
Storage and Viability
Consumers should pay close attention to the storage requirements listed on the packaging, as probiotics are live microorganisms sensitive to temperature and moisture. Products that require refrigeration or are sold in specialized blister packs are designed to maintain the viability of the live organisms until the expiration date.
Third-Party Certification
Looking for a seal from an independent, third-party certification organization provides an extra layer of assurance. Organizations such as USP or NSF International audit manufacturing processes and conduct independent testing to verify that the product’s label accurately reflects the identity and quantity of the live microorganisms inside.