At the federal level in the U.S., plant biostimulants currently operate in a regulatory gray area—there isn’t yet a comprehensive or unified federal framework that governs them. It means that if you want to sell your product in the USA, you will have to make sure you comply with each and every state individually.

Plant biostimulants, depending on the claims made on the label, can possibly fall under "plant regulators". This is in case your product claims that it accelerates, delays, or otherwise alters plant growth or development. This "plant regulator" category is defined by the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).

In that case, the Environmental Protection Agency (EPA) would regulate it like a pesticide, requiring costly and lengthy registration.

There is, however, at USA federal level, the 2018 farm bill (also called "Agriculture Improvement Act of 2018).

This first federal law defines biostimulants as "a substance or micro‑organism that, when applied to seeds, plants, or the rhizosphere, stimulates natural processes to enhance or benefit nutrient uptake, nutrient efficiency, tolerance to abiotic stress, or crop quality and yield" (PUBLIC LAW 115–334—DEC. 20, 2018, page 4908). An effective regulatory framework is yet to be developed.

Then, in 2019, the US EPA released a Draft Guidance on Acceptable Label Claims for Plant biostimulants.

According to this draft guidance, these products are not pesticides as specified in FIFRA:

• plant nutrients and trace elements
• plant inoculants : "product[s] consisting of microorganisms to be applied to the plant or soil for the purpose of enhancing the availability or uptake of plant nutrients through the root system" [40 CFR 152.6(g)(2)]
• soil amendments: Soil amendments (which include soil additives and soil conditioners) are “...product[s] containing a substance or substances intended for the purpose of improving soil characteristics favorable for plant growth” [40 CFR 152.6(g)(3)]
• Vitamin-hormone products: Under FIFRA section 2(v), “the term ‘plant regulator’ shall not be required to include any of such of those nutrient mixtures or soil amendments as are commonly known as vitamin-hormone horticultural products, intended for improvement, maintenance, survival, health, and propagation of plants, and as are not for pest destruction and are nontoxic, nonpoisonous in the undiluted packaged concentration.” Per 40 CFR 152.6(f), “vitamin hormone products” are further described as follows: “A product consisting of a mixture of plant hormones, plant nutrients, inoculants, or soil amendments is not a “plant regulator” under Section 2(v) of FIFRA, provided it meets the following criteria:(1) The product, in the undiluted package concentration at which it is distributed or sold, meets the criteria... for Toxicity Category III or IV; and (2) The product is not intended for use on food crop sites, and is labeled accordingly.”

Now, there is the Proposed Federal Legislation: the Plant Biostimulant Act - it's not yet enacted.

This bill excludes plant biostimulants (i.e., a substance, micro-organism, or mixture thereof that supports a plant's natural processes independently of the biostimulant's nutrient content) from regulation under the Federal Insecticide, Fungicide, and Rodenticide Act.

The bill also requires the Department of Agriculture to study the types of plant biostimulants and practices of plant biostimulant use that best achieve certain results, such as increasing organic matter content (source).

The term plant biostimulant is defined as follows:

PLANT BIOSTIMULANT.—The term ‘plant bio-stimulant’ means a substance, microorganism, or mixture thereof, that, when applied to seeds, plants, the rhizosphere, soil, or other growth media, act to support a plant’s natural processes independently of the biostimu- lant’s nutrient content, thereby improving nutrient availability, uptake or use efficiency, tolerance to abiotic stress, and consequent growth, development, quality, or yield. (source).

Now, there is a newer version in the 119th Congress (2025–2026): S.1907, the Plant Biostimulant Act of 2025:

This newer Act aims to amend the definition of "plant regulator" within FIFRA, primarily to exclude plant biostimulants from that category and mandates USDA conduct a study (with a longer two-year report timeframe) on biostimulant impacts on soil health and sustainability.

So, all this means that there is, today, no federeal legislation that regulates biostimulants and their placing on the US market: you will have to do go through the procedures at state level.

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The sciBASICS Team.