Supplement, medicine or research material: the three legal categories

The difference between a food supplement, a medicine and research material lies mostly not in the ingredient. It lies in three things: the purpose for which the product is supplied, the way it is presented, and the route of administration. A supplement is a food that supplements the normal diet, is taken by mouth, and may not promise to treat disease ^[1][4]. A medicine is anything presented as treating or preventing disease, or acting pharmacologically on physiological functions, and it needs a marketing authorisation ^[5]. Research material is a chemical substance supplied for work in the laboratory, with no route of administration and no claim about people ^[8].

This article sets the three categories side by side. What the "research use only" statement specifically means is analysed in a separate text, as are the criteria that make a medicine prescription-only; they are not repeated here. The useful tool is the comparison table near the end, which shows row by row where the categories part.

How a food supplement is defined

EU law starts from the definition of food. Regulation (EC) No 178/2002 defines food as any substance or product intended to be, or reasonably expected to be, ingested by humans ^[2]. On that basis, Directive 2002/46/EC defines food supplements as foodstuffs intended to supplement the normal diet, which are concentrated sources of nutrients or other substances with a nutritional or physiological effect, and which are marketed in pre-measured forms — capsules, tablets, sachets of powder, ampoules of liquids, drop-dispensing bottles ^[1].

Two consequences of this definition are usually overlooked. First: a supplement does not pass through any approval before supply. The Directive allows Member States to require a simple notification with a model of the label (Article 10), and in Greece this is done electronically with EOF through the service "notification of food supplements placed on the market" ^[1][7]. Notification means the authority is informed, not that it has assessed efficacy. Second: the definition presupposes swallowing. As EOF reminded the public in July 2026, supplements "are administered by mouth" — an injectable preparation cannot be a supplement, whatever its composition ^[9].

The third boundary concerns claims. Regulation (EC) No 1924/2006 allows foods to carry only nutrition and health claims that have been authorised and entered in a Union list ^[3]. Regulation (EU) No 1169/2011 adds an absolute prohibition: food information must not attribute to any food the property of preventing, treating or curing a human disease, or refer to such properties (Article 7(3)) ^[4]. A supplement that promises a cure is not a "bold supplement"; it has stopped being a supplement.

When a product counts as a medicine

Directive 2001/83/EC defines a medicinal product through two alternative limbs, and either one suffices. By presentation: any substance presented as having properties for treating or preventing disease in human beings. By function: any substance that may be used with a view to restoring, correcting or modifying physiological functions by exerting a pharmacological, immunological or metabolic action ^[5]. In Case C-140/07 (Hecht-Pharma) the Court of Justice held that for the second limb the effect must be significant under normal conditions of use, and that classification is made case by case ^[6].

For the comparison with supplements, the decisive clause is Article 2(2): where a product may fall both within the definition of a medicinal product and within the scope of other EU legislation — such as food law — the pharmaceutical rules apply ^[5]. Doubt is not resolved in favour of the lighter regime. A borderline product does not get to "choose" to be a supplement because that is a cheaper way onto the market.

The research-material category and what it declares

The third category is defined neither in pharmaceutical law nor in food law. A synthetic substance manufactured and supplied as a chemical reagent sits within the REACH Regulation, which defines scientific research and development as experimentation, analysis or chemical research carried out under controlled conditions ^[8]. Beyond that, none of these frameworks recognises the "research chemical" as a legal category; the term describes a commercial practice.

That is why research material is defined mainly in the negative. It has no route of administration, no indication, makes no claim about people or animals, and the documents that accompany it — safety data sheet, certificate of analysis — describe the substance, not any outcome. The category holds only as long as that silence holds. Once the presentation acquires a human recipient, the definition of a medicinal product by presentation is triggered, with all its consequences ^[5].

Why the claim decides the category

The clearest example is not a peptide but a vitamin. Ascorbic acid is lawfully sold as a vitamin C tablet in a food supplement, notified and carrying one of the authorised health claims ^[1][3]. It also exists as an injectable medicine with a marketing authorisation, for specific indications and under medical responsibility ^[5]. And it is sold as an analytical reagent by chemical suppliers, with a safety data sheet and nothing else ^[8]. The molecule is one; the legal objects are three.

A single phrase is enough to move a product from one column to another. If the tablet's pack says it "cures colds", the product stops being a lawful supplement and becomes an unauthorised medicine by presentation ^[4][5]. If a reagent supplier's catalogue accompanies the same substance with a promise of "immune support", the same thing happens. As a plain question-and-answer piece puts it, the category depends less on what is in the pack than most people expect.

What the route of administration changes

The route is the second criterion, and it works differently in each column. For food it is a condition of existence: without swallowing there is no food, and so no supplement ^[2][9]. For medicines the route is part of the authorisation — a medicine is authorised for a specific route, and parenteral administration also affects how it is supplied, as explained in the article on prescription peptides ^[5]. For research material the route simply does not exist.

That absence has practical value for a buyer. A product description that mentions subcutaneous or intramuscular administration, an "injection" or a "protocol" no longer describes a reagent. It describes an unauthorised medicine, whatever the label says about intended use.

Comparison table of the three categories

The table also reads as a checklist. If a product declares one column but behaves according to another — a supplement in injectable form, a reagent with an indication, a "natural" preparation promising a cure — the mismatch is the signal. The legal category follows the product's behaviour, not its declaration ^[5][6].

What a buyer takes from this

• Check what the product claims, not only which category the label names; the claim prevails ^[4][5].
• Check whether the accompanying documents fit the declared category: a reagent comes with a safety data sheet, not administration instructions ^[8].
• An injectable "supplement" does not exist lawfully; EOF has said so explicitly ^[9].
• Research material is not a cheaper version of a medicine nor a stronger version of a supplement; it is a different legal object with a different purpose.