- M & H Manufacturing
- M. J. Biopharm
- MacroPhar
- MacroPhar Lab
- Masa Lab
- Mayoly Spindler
- Mebo
- Medifive
- Medinova
- Medline
- Medochemie
- Medreich
- Mefar Ilac San
- Mega Lifesciences
- Meiji
- Meiji Seika Pharma
- Menarini-Von Heyden
- Merckle
- Micro Labs
- Millimed
- Mitsubishi Tanabe Pharma
- Montana Marketing
- Montavit
- MSD
- Mylan
- Myungmoon Pharm