Bayer

• 1. Introduction

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  Bayer AG began not as a pharmaceutical giant but as a dyestuffs factory in Barmen, Germany, in 1863. Friedrich Bayer, a dye salesman, and Johann Friedrich Weskott, a master dyer, formed a partnership to sell fuchsine and aniline dyes. Neither man could have imagined that aniline chemistry would eventually lead their small firm toward medicines, insecticides, and one of the most controversial corporate acquisitions in modern history. What happens when a company built on color pigments becomes the maker of aspirin, heroin, and Roundup weedkiller? And what does it mean that the same corporate lineage runs from a Nobel Prize in medicine to the gas chambers of Auschwitz? These are the questions Bayer's story forces us to ask.

• 2. Aspirin and Its Contested Origins

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  Acetylsalicylic acid had actually been described by French chemist Charles Frederic Gerhardt back in 1853, before Bayer ever touched it. Bayer scientists worked to refine the compound, and by 1899 the trademarked name Aspirin was registered worldwide. The drug's origins, however, remain disputed. Arthur Eichengrün, a Bayer chemist who was imprisoned at Theresienstadt concentration camp in 1944, claimed he was the first to develop a formulation that eliminated the nausea and gastric pain that plagued earlier versions. He also said he invented the name and first tested the compound himself. Bayer's official account attributed the discovery to Felix Hoffmann, described as an Aryan research assistant motivated by his father's arthritis. Most mainstream historians today credit both Hoffmann and Eichengrün without resolving the dispute cleanly. Whatever the origins, the product's reach became staggering: by 2011, roughly 40,000 tons of aspirin were produced each year, with 10-20 billion tablets consumed in the United States alone. Aspirin's standing is now so established that it sits on the World Health Organization's List of Essential Medicines. Bayer lost the aspirin trademark in the United States, France, and the United Kingdom after its American assets were confiscated during World War I, but the name remains a registered Bayer trademark in more than 80 countries, including Canada, Germany, and Switzerland.

• 3. Products That Shocked and Healed

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  Heroin was a Bayer trademark. From 1898 to 1910, Bayer marketed diacetylmorphine as a cough suppressant and over-the-counter treatment for pneumonia and tuberculosis, presenting it as a non-addictive substitute for morphine. Bayer's director of pharmacology wanted a name that avoided anything too complicated, so the company chose heroisch, the German word for heroic. Bayer's scientists did not synthesize heroin first, but the company was the driving force in making it commercially available. In 1903, Bayer licensed the patent for diethylbarbituric acid from chemists Emil Fischer and Joseph von Mering, marketing it as the sleep aid Veronal. Further research at Bayer led to phenobarbital in 1911, and its powerful anti-epileptic properties were identified in 1912. Phenobarbital remained one of the most widely used epilepsy treatments through the 1970s and is still on the WHO's essential medicines list as of 2014. Suramin, discovered by Bayer scientists in 1916 during World War I, became an anti-parasite drug still sold by Bayer under the brand name Germanin. Bayer kept the formula secret for commercial reasons; it was only decoded and published in 1924 by Ernest Fourneau and his team at the Pasteur Institute.

• 4. IG Farben and the Holocaust

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  In 1925, Bayer merged with five other German companies, including BASF and Hoechst, to form IG Farben, at the time the world's largest chemical and pharmaceutical company. Bayer's Institute of Pathology and Bacteriology, led by Gerhard Domagk, made a breakthrough discovery in the early 1930s: prontosil, the first commercially available antibacterial drug and the forerunner of all antibiotics. Domagk won the Nobel Prize in Physiology or Medicine in 1939, but the Nazi Party forced him to refuse it, because German citizens had been barred from accepting Nobel prizes after the 1935 Peace Prize went to the pacifist Carl von Ossietzky. Under the Nazi regime, IG Farben used slave labor in factories built inside concentration camps. By 1943, nearly half of IG Farben's 330,000-person workforce consisted of slaves or conscripts, including 30,000 prisoners from Auschwitz alone. Helmuth Vetter, an SS captain and Bayer group employee, conducted medical experiments on inmates at Auschwitz and at the Mauthausen concentration camp. In one documented study of an anaesthetic, the company paid 170 Reichsmarks per person to use 150 female Auschwitz inmates. A Bayer employee wrote to Rudolf Hoss, the Auschwitz commandant, that the women "died during the experiments" and requested another group "to the same number and at the same price." After the war, Fritz ter Meer, who helped plan the Monowitz camp and the Buna Werke factory where 25,000 forced laborers were deployed, was tried at the IG Farben Trial. He was sentenced to seven years but released in 1950 and, despite his conviction as a war criminal, was elected chairman of Bayer AG's supervisory board in 1956, a position he held until 1964. Bayer's CEO Helge Wehmeier offered a public apology to Elie Wiesel in 1995.

• 5. Postwar Rebuilding and Recurring Scandal

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  IG Farben was split into its constituent companies in 1951, and Bayer re-emerged as Farbenfabriken Bayer AG before taking the name Bayer AG in 1972. The company recovered quickly, playing a role in the West German economic revival. Controversy, however, followed close behind. In 1978, Bayer purchased Miles Laboratories, gaining Factor VIII, a clotting agent used to treat hemophilia. By 1983, the CDC had identified contaminated blood products as a source of HIV infection. Bayer and its competitors developed heat-treated replacements, introduced in early 1984. But documents that emerged in 2003 showed that Cutter Laboratories, Bayer's subsidiary, continued to sell unheated blood products in Malaysia, Singapore, Indonesia, Japan, and Argentina until 1985, to offload inventory it could no longer sell in Europe and the United States. Thousands of hemophiliacs who received the tainted product developed AIDS. In 1997, Bayer and three other makers agreed to pay $660 million to settle cases on behalf of more than 6,000 infected hemophiliacs in the United States. In the late 1990s, Bayer also introduced the statin drug Baycol; after 52 deaths were linked to it, the drug was discontinued in 2001. Trasylol, used to control surgical bleeding, was withdrawn worldwide in 2007 after evidence of increased mortality emerged, partly because Bayer scientists had failed to share a relevant ongoing study with the FDA during a 2006 safety review.

• 6. The Monsanto Disaster

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  In May 2016, Bayer offered to buy the American biotechnology company Monsanto for $62 billion. Monsanto rejected the first offer as too low. By September 2016, Monsanto agreed to a revised $66 billion offer, making it the largest acquisition ever undertaken by a German company. Regulatory approval required Bayer to sell significant agricultural assets to BASF. The European Union approved the deal on the 21st of March 2018, and the United States approved it on the 20th of May 2018. The sale closed on the 7th of June 2018, and the Monsanto brand was discontinued. Two months after the deal closed, a U.S. jury ordered Monsanto to pay $289 million to a school groundskeeper who claimed the herbicide Roundup had caused his non-Hodgkin's lymphoma. Bayer's share price fell roughly 14%, erasing about $14 billion in market value on the day of the verdict. That figure was later reduced to $78.5 million on appeal, then further to $21.5 million in June 2020. Roundup litigation multiplied. By 2023, around 165,000 claims had been filed against Roundup, with more than 50,000 still pending. In June 2020 alone, Bayer agreed to pay $9.6 billion to settle more than 10,000 lawsuits, a sum meant to cover 75% of outstanding claims. By 2023, Bayer's market value had declined by more than 60% from its 2016 level, leaving the company worth less than half of what it paid for Monsanto.

• 7. Bayer Today

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  Crop Science, representing Bayer's agricultural operations, accounted for 48.8% of the company's sales by 2023. Pharmaceuticals contributed 38.0% and Consumer Health 12.7%. Top pharmaceutical products as of 2014 included Xarelto, a blood thinner that Bayer and Johnson and Johnson settled for $775 million in 2019 over claims that patients had not been properly warned about fatal bleeding risks. In May 2026, Bayer announced plans to buy Perfuse Therapeutics for up to $2.45 billion, including a $300 million upfront payment, signaling continued expansion into new therapeutic areas. Among the company's consumer brands are Aspirin, Aleve, Claritin, Coppertone, and Berocca. The Bayer cross logo, introduced in 1904, remains an illuminated landmark in Leverkusen. The company also owns the Bundesliga football club Bayer Leverkusen, tracing back to the sports club TuS 04 it founded in 1904. Bayer's R&D expenditure grew by 22.6% in 2025, the highest rate among any of the company's recent financial reporting periods.