Bayer AG
Pharmaceuticals / Life Sciences / AgricultureFounded 1863- Updated July 2025
Reviewed by Swet Parvadiya
Last reviewed: July 2025
CorpDigest
Bayer AG
Company History
Founded 1863 in Leverkusen, North Rhine-Westphalia, Germany
Last reviewed: 2025-07-15 · By Swet Parvadiya
Founded in 1863 as a dyestuffs manufacturer by Friedrich Bayer and Johann Friedrich Weskott, the company invented and trademarked Aspirin in 1899 and marketed heroin as a cough suppressant the year before — a historical footnote that appears in virtually every Bayer article and still surprises most readers. Friedrich Bayer, a salesman for a silk dye trading company, and Johann Friedrich Weskott, a master dyer, founded Friedr.
Friedrich Bayer (1825-1880) was the co-founder of Bayer AG, establishing the company in 1863 as a dyestuffs manufacturer in Barmen, Germany. A dye salesman by trade, Bayer recognized the commercial potential of synthetic aniline dyes that were replacing natural dyes in the textile industry. He partnered with Johann Friedrich Weskott, a master dyer, to create Farbenfabriken vorm. Friedr. Bayer & Comp., with Bayer handling commercial operations and Weskott managing production. The company's early products included fuchsine and aniline dyes. After Friedrich Bayer's death in 1880, the company was converted into a joint-stock corporation, and his son Friedrich Bayer Jr. (1851-1920), a chemist, joined and led the company's expansion into pharmaceuticals, culminating in the 1899 launch of Aspirin.
Johann Friedrich Weskott (1821-1876) was the co-founder and technical partner of Bayer AG, establishing the company alongside Friedrich Bayer in 1863 in Barmen, Germany. A master dyer by profession, Weskott brought manufacturing expertise and technical knowledge of dye production processes to the partnership. While Bayer handled commercial operations, Weskott managed production and quality. He died in 1876, before the company's major diversification into pharmaceuticals, but his technical foundation enabled the manufacturing capabilities that supported Bayer's expansion from a small dyeworks into a global chemical enterprise.
Friedrich Bayer and Johann Friedrich Weskott established Farbenfabriken vorm. Friedr. Bayer & Comp. in Barmen, Germany, as a manufacturer of synthetic fuchsine and aniline dyes. The company capitalized on the emerging coal-tar chemistry revolution that was transforming the textile industry.
Chemist Felix Hoffmann synthesized acetylsalicylic acid in a stable, pure form, and Bayer registered the trademark 'Aspirin' on March 6, 1899. The drug became the world's first mass-market synthetic pharmaceutical and remains one of the most widely consumed medications in history, with over 10 billion tablets taken annually.
Bayer began marketing heroin (diacetylmorphine) as a non-addictive substitute for morphine, trademarking it as a cough suppressant and treatment for tuberculosis and pneumonia. The drug remained a Bayer trademark until after World War I.
Bayer licensed diethylbarbituric acid from Emil Fischer and Joseph von Mering, marketing it as Veronal—the first barbiturate sleep aid. Systematic research led to the discovery of phenobarbital in 1911, which became a mainstay of epilepsy treatment and remains on the WHO List of Essential Medicines.
Bayer's U.S. assets and trademarks, including the Aspirin trademark, were confiscated by the Alien Property Custodian and sold to Sterling Products. The company lost its American market for decades and was forced to rebuild its international presence from scratch.
Bayer merged with BASF, Hoechst, Agfa, and other German chemical companies to form IG Farbenindustrie AG (IG Farben), creating the world's largest chemical and pharmaceutical conglomerate. IG Farben's subsequent role in the Nazi war effort would lead to its dissolution after World War II.
Gerhard Domagk, leading a research team at Bayer Laboratories, developed Prontosil—the first sulfonamide antibacterial and forerunner of modern antibiotics. Domagk received the Nobel Prize in Physiology or Medicine in 1939 for this discovery, which saved countless lives from bacterial infections.
Following World War II, the Allied Control Council dissolved IG Farben due to its role in the Holocaust and Nazi war effort. Bayer was reincorporated as Farbenfabriken Bayer AG and quickly regained its position as a leading global chemical and pharmaceutical company during West Germany's economic miracle.
Bayer purchased Sterling Winthrop's over-the-counter drug business from SmithKline Beecham for $1 billion, reclaiming the U.S. and Canadian trademark rights to 'Bayer' and the Bayer Cross that had been lost during World War I, along with ownership of the Aspirin trademark in Canada.
Bayer acquired Schering AG in a white knight defense against Merck KGaA's hostile bid, adding significant pharmaceutical capabilities including the Mirena contraceptive franchise and oncology assets. The acquisition was the largest in Bayer's history until the Monsanto deal.
Bayer spun off its materials science division as Covestro through an IPO on the Frankfurt Stock Exchange, focusing the remaining company on life sciences and ending its presence in plastics and polymers.
Bayer completed the acquisition of Monsanto for $66 billion ($63 billion equity plus assumed debt), the largest acquisition by a German company in history. The deal required divestment of significant assets to BASF for regulatory approval and was immediately followed by the first Roundup cancer verdict, triggering litigation that has now exceeded 165,000 claims.
Bayer agreed to settle approximately 113,000 Roundup claims for $10.9 billion, while maintaining that glyphosate is safe and does not cause cancer. The settlement did not resolve all claims, and new lawsuits continued to emerge.
Bill Anderson, former CEO of Roche Pharmaceuticals and Genentech, became the first American Chairman of the Board of Management and CEO of Bayer AG on June 1, 2023, succeeding Werner Baumann. Anderson launched a comprehensive transformation program with five strategic priorities.
Bayer launched the Dynamic Shared Ownership operating model under CEO Bill Anderson, eliminating roughly 50% of management positions, reducing hierarchy layers, and cutting total headcount by over 12,000—from 102,048 to 89,556 by mid-2025. The company targets $2 billion in annual savings by 2026.
The U.S. FDA approved Nubeqa (darolutamide) for metastatic castration-sensitive prostate cancer, the drug's third indication, based on the Phase III ARANOTE trial showing 40% risk reduction in high-volume disease and 70% in low-volume disease. Nubeqa achieved blockbuster status in 2024 with $1.66 billion in sales.
Bayer acquired Schering AG in a white knight defense against Merck KGaA's hostile bid, adding significant pharmaceutical capabilities including the Mirena contraceptive franchise, oncology assets, and a strong European pharmaceutical sales force. The acquisition was the largest in Bayer's history until the Monsanto deal.
Bayer acquired Monsanto to create the world's largest integrated agricultural inputs company, combining Bayer's crop protection chemistry with Monsanto's seed genetics, biotechnology traits, and digital agriculture platform (Climate FieldView). The deal required divestment of significant assets to BASF for regulatory approval.
Bayer purchased Sterling Winthrop's over-the-counter drug business from SmithKline Beecham to reclaim the U.S. and Canadian trademark rights to 'Bayer' and the Bayer Cross that had been confiscated during World War I, along with ownership of the Aspirin trademark in Canada.
Bayer chemist Felix Hoffmann synthesised acetylsalicylic acid in pure, stable form on August 10, 1897 — creating aspirin, the world's best-selling drug for most of the 20th century and still consuming 40,000 tonnes annually. Bayer trademarked 'Aspirin' in 1899 and launched it as the first synthetic pharmaceutical sold in powder form worldwide, establishing the company's pharmaceutical brand globally and pioneering modern drug commercialisation. Aspirin's success funded Bayer's subsequent pharmaceutical R&D and established the company as both a chemistry and healthcare business, a dual identity — chemicals and life sciences — that has defined Bayer's strategy ever since though the chemicals division was spun off as Lanxess in 2004.
World War I devastated Bayer internationally when the US, UK, and other Allied nations seized Bayer's foreign assets and trademarks as enemy property — including the Aspirin trademark in the US (sold to Sterling Drug for $5.31 million), forcing Bayer to compete in America under a different name for 72 years. Germany's use of chemical weapons in WWI — the chlorine gas at Ypres (1915) was developed with support from German chemical companies' infrastructure — tarnished the entire German chemical industry's reputation. Bayer's pre-war global trademarks weren't fully recovered until the 1994 repurchase of Sterling Winthrop's non-prescription drug business for $1 billion, finally reunifying the Aspirin trademark with Bayer's name in North America after 80 years.
Bayer's 2018 acquisition of Monsanto for $63 billion — the largest all-cash acquisition in history — proved catastrophic when it inherited $20 billion in liability for Roundup weedkiller cancer claims, as Monsanto had concealed scientific evidence suggesting glyphosate caused non-Hodgkin's lymphoma. Bayer paid $10.9 billion to settle 100,000+ lawsuits in 2020 and faces ongoing claims totalling $20+ billion, while the Monsanto name itself was retired in 2018 due to its toxicity. Bayer's stock fell 40% from the acquisition price, destroying €30+ billion in market capitalisation, and the deal exemplifies due diligence failure — external advisors flagged glyphosate litigation risk but management discounted it, assuming scientific consensus on safety would prevail in courts.
While Bayer's headquarters is in Leverkusen, the major industrial explosion that devastated the Leverkusen chemical park in July 2021 affected Currenta, the site manager jointly owned by Bayer, releasing toxic substances and killing two workers — adding environmental liability and reputational pressure to the already-strained company. The explosion exposed risks of Bayer's legacy chemical operations at the densely-populated Leverkusen site and triggered regulatory investigations into site safety management. Coming amid the Monsanto litigation crisis, the explosion reinforced negative perceptions of Bayer's risk management across its diversified industrial operations, though the financial impact was limited compared to the ongoing multi-billion Monsanto liability that remains Bayer's existential challenge.
Bayer regained corporate independence on 19 December 1951 when Allied High Commission Law No. 35 ordered the breakup of IG Farbenindustrie AG, the chemicals cartel that had absorbed Bayer in 1925 along with BASF, Hoechst, Agfa and Cassella. The original eight-way split proposed by US prosecutors at the Nuremberg IG Farben trial was rejected as economically unworkable, and Allied negotiators settled on three successor companies: Farbenfabriken Bayer AG in Leverkusen, Badische Anilin- und Sodafabrik AG in Ludwigshafen, and Farbwerke Hoechst AG in Frankfurt. Bayer received the IG Farben assets located in the British occupation zone, including the Leverkusen, Dormagen, Uerdingen and Elberfeld plants employing roughly 33,000 workers. The IG Farben holding company itself remained in liquidation for the next six decades, finally winding up in 2012 after settling Holocaust survivor compensation claims. Bayer's new chairman Ulrich Haberland, a chemist who had run the Leverkusen works through the war, relisted the company on the Düsseldorf stock exchange in 1952 and rebuilt its consumer franchise around aspirin, the Bayer cross trademark recovered from the US Alien Property Custodian in 1994, and new polymers like polyurethane that chemist Otto Bayer had patented for IG Farben in 1937.