| MES | 4432-31-9 | Other calcium Channel Blockers | 1 |
| MES Hydrate | | Other calcium Channel Blockers | 1 |
| MES Sodium | | Other calcium Channel Blockers | 1 |
| Meadowsweet herb | | Herbal remedies | 1 |
| Mebhydrolin Napadisylate | | Antihistamines | 1 |
| Mecamylamine | 60-40-2 | Nicotinic acid derivatives | 1 |
| Mecasermin | 68562-41-4 | Somatropin Agonists | 1 |
| Mechlorethamine | 51-75-2 | Alkylating agents | 1 |
| Medetomidine hydrochloride | 86347-15-1 | | 1 |
| Meglumine | 6284-40-8 | Contrast Media | 1 |
| Meldonium | 86426-17-7 | | 1 |
| Meldrum's Acid | 2033-24-1 | | 1 |
| Melengestrol Acetate | 2919-66-6 | Progestagens | 1 |
| Melitracen Hydrochloride | 10563-70-9 | | 1 |
| Melperone | 3575-80-2 | | 1 |
| Melphalan hydrochloride | 3223-07-2 | | 1 |
| Menadione Sodium Bisulphite | 6147-37-1 | Vitamins | 1 |
| Menbutone | 74381-53-6 | | 1 |
| Menotropins | 61489-71-2 | Gonadotrophic | 1 |
| Mentha pulegium | | Herbal remedies | 1 |
| Menthae piperitae folium | | Herbal remedies | 1 |
| Menthae viridis folium | | Herbal remedies | 1 |
| Mepenzolate | 25990-43-6 | Anticholinergics/Parasympathemimetics | 1 |
| Mepolizumab | 196078-29-2 | Anti-asthma | 1 |
| Mertansine | 139504-50-0 | Oncolytics | 1 |
| Mesterolone | 1424-00-6 | Androgens | 1 |
| Metallic Silver Powder | 7440-22-4 | Antimicrobial agents | 1 |
| Methacycline | 914-00-1 | Tetracyclines | 1 |
| Methamphetamine | 537-46-2 | Psychostimulants | 1 |
| Methohexital | 151-83-7 | Intravenous anesthetics | 1 |
| Methopabate | 4093-29-2 | | 1 |
| Methsuximide | 77-41-8 | Adrenergic agents | 1 |
| Methyclothiazide | 135-07-9 | Diuretics | 1 |
| Methyl (3aR,4R,6S,6aS)-4-((tert-butoxycarbonyl)amino)-3-(pentan-3-yl)-3a,5,6,6a-tetrahydro-4H-cyclopenta[d]isoxazole-6-carboxyla | 229613-93-8 | | 1 |
| Methyl 2-(4-(4-(4-(hydroxydiphenylmethyl)piperidin-1-yl)butanoyl)phenyl)-2-methylpropanoate | 154477-55-1 | Intermediates | 1 |
| Methyl 4-Chlorocinnamate | 7560-44-3 | Dermatics | 1 |
| Methyl Parahydroxybenzoate | 99-76-3 | | 1 |
| Methyl cellulose | 9004-67-5 | Laxatives | 1 |
| Methyl pyrrolidone | 872-50-4 | | 1 |
| Methyl red | 439685-79-7 | | 1 |