Merck & Co., Inc. provides healthcare solutions worldwide. It operates through four segments: Pharmaceutical, Animal Health, Healthcare Services, and Alliances. The company offers therapeutic and preventive agents to treat cardiovascular, type 2 diabetes, chronic hepatitis C virus, HIV-1 infection, intra-abdominal, fungal infection, insomnia, and inflammatory diseases. It also provides neuromuscular blocking agents; cholesterol modifying medicines; and anti-bacterial and vaginal contraceptive products.

In addition, the company offers products to prevent chemotherapy-induced and post-operative nausea and vomiting; treat non-small-cell lung, ovarian and breast, thyroid, and cervical cancer, as well as brain tumors; and prevent diseases caused by human papillomavirus, as well as offers vaccines for measles, mumps, rubella, varicella, shingles, rotavirus gastroenteritis, and pneumococcal diseases.

Further, it provides antibiotic and anti-inflammatory drugs to treat infectious and respiratory diseases, fertility disorders, and pneumonia in cattle, bovine, and swine; vaccines for poultry; parasiticide for sea lice in salmon; and antibiotics and vaccines for fishes. Additionally, the company offers companion animal products, such as ointments; diabetes mellitus treatment and anthelmintic products; products to treat fleas and ticks in dogs and cats; fertility management products for horses; vaccines for dogs, cats, and horses; and products for protection against bites from fleas, ticks, mosquitoes, and sandflies.

It has collaborations with AstraZeneca PLC; Bayer AG; Eisai Co., Ltd.; and Intec Pharma Ltd. The company serves drug wholesalers and retailers, hospitals, government agencies and entities, physicians, distributors, veterinarians, animal producers, and managed health care providers. Merck & Co., Inc. was founded in 1891 and is headquartered in Kenilworth, New Jersey.