The corporation covers seven major therapeutic areas: cardiovascular, central nervous system, diabetes, internal medicine, oncology, thrombosis, and vaccines.

[4] Sanofi was founded in 15 February 1973[5] as a subsidiary of Elf Aquitaine (a French oil company subsequently acquired by Total), when Elf Aquitaine took control of the Labaz group, a pharmaceutical company formed in 1947 by Sociéte Belge de l'Azote et des Produits Chimiques du Marly;[6] Labaz developed benziodarone in 1957.

[7]: 146  In 1993, Sanofi made a move into the Eastern Europe market by acquiring a controlling interest in Chinoin, a Hungarian drug company whose 1992, sales totaled about US$104 million.

[8][9] In the same year, Sanofi made its first significant venture into the US, and strengthened its presence in Eastern Europe, by first partnering with Sterling Winthrop and then acquiring the prescription pharmaceuticals business in 1994.

[18]: 10  Hoechst, one of the companies that resulted from the post-WWII split of IG Farben, had seven primary businesses: Hoechst Marion Roussel (pharmaceuticals), AgrEvo (a joint venture with Schering in crop protection agents and pest control products), HR Vet (veterinary products), Dade Behring (diagnostics), Centeon, Celanese (chemicals), and Messer (chemicals).

[30] One of the largest risks in the deal for both sides was the fate of the patents protecting Clopidogrel (Plavix), which was one of the top-selling drugs in the world at the time and the major source of Sanofi's revenue.

[46] In October Sanofi-Aventis announced that it would lay off about 1700 US employees (about 25% of its US workforce) because of restructuring triggered by growing generic competition and other factors, and that the company would focus its US operations on diabetes, atrial fibrillation, and oncology.

Sanofi sought support for its internal cancer research program and also took on an obligation to acquire Warp Drive if certain milestones were met.

[65] In December 2019, the company announced that it would acquire Synthorx for $2.5 billion ($68 per share), adding the lead product candidate THOR-707 (SAR444245), a form of interleukin-2 (IL-2) being developed for use against multiple solid tumors.

[71] In June, the company announced that it had agreed a potential $2 billion deal with Translate Bio, expanding an already existing collaboration for COVID-19 treatments.

[78] In November, Sanofi announced that it would acquire Kiadis Pharma for €308 million (around $359 million, or €5.45 per share), expanding its immuno-oncology pipeline with the acquisition of Kiadis's three clinical compounds: K-NK002 in Phase II trials for hematopoietic stem cell transplants in blood cancer, K-NK003 for relapsed or refractory acute myeloid leukemia, and K-NK-ID101 for COVID-19.

[86] In December, the company announced that it would acquire Origimm Biotechnology GmbH and its acne vaccine candidate (ORI-001),[87][88] as well as Amunix Pharmaceuticals, for an initial $1 billion plus potentially $200 million in additional milestones.

[89] In April 2022, Sanofi broke ground on its biggest industrial investment, a $638m vaccine and enzymes production facility in Tuas, Singapore, targeted for completion in 2025.

[91] In the fall of 2023, Sanofi announced plans to separate the OTC and focus on its key prescription production, increasing investment and reducing costs.

[107][108] The reason given by Sanofi was that the products had been found to potentially have inaccurate dosage delivery systems, which might include failure to deliver the drugs.

Canadian customers were asked to immediately return the Allerject product to their local pharmacy to obtain an alternate epinephrine auto-injector.

"[111] The US Food and Drug Administration (FDA) also filed a news release,[110] confirming that the recall involved all Auvi-Q currently on the market in the United States.

[112] The alternate products expected to most commonly replace the recalled Sanofi devices were the EpiPens made by Mylan in the US and by Pfizer—under license from Mylan—in Canada.

Maylan was expected to benefit from the recall by its competitor Sanofi, according to a report published in the Fierce Pharma newsletter of 2 November 2015.

As Bernstein analyst Ronny Gal wrote in a note to clients,"....it is very hard to see Auvi-Q returning to the market, as it will need to be redesigned and face uphill battle to recapture patient trust after the recall.

[116] – Cardiovascular – Dermatology – Diabetes – Endocrinology – Gastroenterology – Hematology – Infectious diseases – Metabolic – Neurology – Oncology – Other – Over the counter – Pain – Respiratory and inflammatory diseases – Rheumatology – Urology The company also produces a broad range of over-the-counter products, among them Allegra, IcyHot for muscle pain, Gold Bond for skin irritation, and Selsun Blue dandruff shampoo.

[127] In 2013, Sanofi announced that another candidate from its collaboration with Regeneron, a monoclonal antibody against the interleukin 6 receptor, sarilumab, had better efficacy than placebo in its first Phase III trial in rheumatoid arthritis.

[128] As of 31 December 2013:[133]: 185 In January 2012, Sanofi moved its head office location to 54, Rue La Boétie in the 8th arrondissement of Paris.

[135] In November 2022, Sanofi moved into its new global headquarters in the 17th arrondissement of Paris, at 46-48 Avenue de la Grande Armée.

[140] In June 2010, Sanofi and the Charité University of Berlin signed a cooperation agreement for the research and development of medicines and therapies.

By April 2012, the FDA had found dozens of documented problems with sterility at the plant, including mold, nesting birds, and rusted electrical conduits.

[148] As of August 2020, COVID-19 vaccine development in Sanofi underscored its fundamental competitiveness weakness, with which management has been struggling and failed to deal with for many years, beyond cutting more costs.

Unfortunately, even though the approach of Sanofi-GSK is based on pre-existing, approved platforms and technology (as with Flublok flu), without reinventing the wheel of the necessary infrastructure,[149] the company lagged behind many other rivals in delivering a working vaccine.

[152] According to CNBC reports,[153] as part of the $2.1 billion US government deal, more than 750 million went to supporting Sanofi-GSK in vaccine development and clinical trials.

[160] In June 2021, Sanofi partnered with Capgemini, Orange & Generali to launch Future4care, an all-European start-up accelerator centered on digital health.