Guidance
Substances recognised as medicinal by function in veterinary medicines
List of substances recognised as medicinal by function.
This is part of a guidance collection and should be read in association with Advertising non-medicinal veterinary products.
The following is a list of substances recognised as medicinal by function. Some have established limits below which they are considered non-medicinal.
Any product applied to an animal that contains a substance on this list is considered medicinal by function unless that substance is below the stated limit.
Unless otherwise stated in this list, any product containing an active substance present in an authorised veterinary medicine as presented on the VMD’s Product Information Database is considered medicinal by function.
This list is not exhaustive.
| Substance | Notes |
|---|---|
| Acacia catechu | Apoptotic and NSAID. Medicinal by function at any level |
| Acetylcysteine / N-Acetylcysteine | Mucolytic, medicinal at any level |
| Adelmidrol | ALIAmide drug, medicinal at any level |
| Adenosylmethionine (aka SAMe) | Considered Medicinal by Function in any product presented for effects on mood, liver or joint health |
| Attapulgite | The inclusion of this substance in a “supplement” serves no nutritional purpose, its sole documented effect is to bind pathogenic material in the digestive tract. Orally administered products containing attapulgite are considered medicinal by function |
| Belladonna | Medicinal at any level |
| Benzalkonium Chloride | Medicinal when included in any topical product at a concentration exceeding 0.02% |
| Benzoyl Peroxide | Medicinal at any level |
| Bismuth Sub Carbonate | Medicinal by function when orally administered |
| Bloodroot (sanguinaria canadensis) extract | Sanguinarine is an escharotic and therefore medicinal by function |
| Bronopol | Medicinal by function. Permitted as a preservative in leave-on and rinse-off topical products at concentrations not exceeding 0.1% |
| Boric Acid | Medicinal by function when included at levels exceeding Talc - 5% Oral hygiene – 0.5% All other products – 3% Products containing this substance require the warning “Do not use on damaged skin” |
| Camphor | Topical use only: Medicinal by function in product exceeding 4% |
| Cannabidiol (CBD) | Whether as CBD isolate, or in the form of “broad spectrum” or “full spectrum” hemp plant oil. Medicinal by function at any level |
| Cannabigerol (CBG) | Medicinal by function. Metabolises into CBD |
| Capsaicin | Medicinal by function when applied topically at concentrations exceeding 0.012% due to analgesic effects |
| Cetylpyridinium Chloride | Medicinal by function in oral hygiene products for cat and dogs exceeding 0.0012% concentration |
| Chlorhexidine Gluconate | Medicinal by function when applied to intact skin at concentrations exceeding 4%, or when included in first aid products at concentrations exceeding 0.3% |
| Colostrum | Manufactured colostrum, including that from cows that have been treated to ensure the colostrum will contain particular antibodies, require an MA. A colostrum or colostrum-based product containing pure colostrum does not require an MA, provided that no reference is made to disease, immunoglobulin content, antibodies, IgA, IgG, or the immune system |
| Copper Naphthenate | Medicinal by function at any level |
| Diazolidinyl Urea | Topical use only: Medicinal by function at concentrations exceeding 0.5% |
| Dibenzoyl Peroxide | Topical use only: Medicinal by function at concentrations exceeding 2.5% |
| Dichlorophen | Topical use only: Medicinal by function at concentrations exceeding 0.5% |
| Diflubenzuron | Medicinal by function at any level |
| DMDM hydantoin | Topical use only: Medicinal by function at concentrations exceeding 0.6% |
| Foxglove (Digitalis) | Medicinal by function at any level |
| Guanidinopropionic Acid | Medicinal by function at any level |
| Iodine | Topical use only: Medicinal by function at concentrations exceeding 0.3% |
| Iodoform | Medicinal by function at concentrations exceeding 10% |
| Ketaconazole | Topical use only: Medicinal by function at concentrations exceeding 1% |
| Lactic Acid | Topical use only: Medicinal by function at concentrations exceeding 5% |
| Methyl Salicylate (wintergreen) | Topical use only: Medicinal by function at concentrations exceeding 0.25% |
| Nicotine | Medicinal by function at any level |
| Palmitoylethanolamide (PEA) | Micronised and Ultra-Micronised PEA is Medicinal by Function. Has anti-inflammatory and antinociceptive properties. A synthesised alternative to CBD. Unmicronised (D10 ≥3.19µm, D50 ≥21.1µm, D90 ≥62.7 µm) – Not Medicinal by function due to apparent inefficacy. Will still be medicinal by presentation where reference is made to the properties and purposes of micronised and ultra-micronised PEA. Consequently, all reference to finer forms of PEA and its properties, effects, and uses are prohibited. No indication may be made for systems on which medicinal PEA is efficacious. Products containing unmicronised PEA must be declared as such. This declaration must be readily apparent on the packaging and wherever a reference to PEA is made in the products presentation. The use of other substances to increase the absorbency of unmicronised PEA will cause the product to be medicinal by function |
| Parabens | Topical use only: Medicinal by function at concentrations exceeding 0.25% |
| Phenoxyethanol | Topical use only: Medicinal by function at concentrations exceeding 2% |
| Potassium Iodide | Medicinal by function at concentrations exceeding 1% for oral use |
| Potassium Sorbate | Topical and oral hygiene use only: Medicinal by function at concentrations exceeding 0.2% |
| Povidone Iodine | Topical use only: Medicinal by function at concentrations exceeding 3% |
| Pyrethrum | Medicinal by function at any level |
| Resmethrin | Medicinal by function at any level |
| Scutellaria baicalensis (Chinese Scullcap) | NSAID. Medicinal by function at any level |
| Sodium bicarbonate | Except in feeds exclusively for ruminants. Inclusion in orally administered products in concentrations greater than 1% is considered medicinal by function due to its recognised antacid activity |
| Thymol | Medicinal by function at any level |
| Undecylenic Acid | Topical use only: Medicinal by function at concentrations exceeding 2% |
| Valerian Root | Medicinal by function at concentrations exceeding 2% |
| Willow Bark (“White Willow”, “Willow Extract”, Salix Alba) | Medicinal by function at any level |
| Zinc Chloride | Topical use only: Medicinal by function at concentrations exceeding 2.5%. Oral Hygiene use only: Medicinal by function at concentrations exceeding 0.002% |
| Zinc Oxide | Topical use only: Medicinal by function at concentrations exceeding 5% |
| Zinc Sulphate | Topical use only: Medicinal by function at concentrations exceeding 5% |
Updates to this page
Published 14 January 2026