PRESS RELEASE Paris

Sanofi Returns to Growth in Q4 2013

In order to facilitate an understanding of our operational performance, we comment on our business net income statement. Business net income(1) is a non-GAAP financial measure. The consolidated income statement for 2013 is provided in Appendix 4 and a reconciliation of business net income to consolidated net income in Appendix 3. Consolidated net income for 2013 was 3,717 million, compared to 4,889 million(2) for 2012. Consolidated EPS for 2013 was 2.81 versus 3.71(2) for 2012.

Commenting on the Group s performance in Q4 2013, Sanofi Chief Executive Officer, Christopher A. Viehbacher said, Sanofi s growth profile emerged in Q4 2013 with total sales growing 6.5% at CER and growth platforms(3), which represented 72.9% of sales, increasing 10.0% at CER. Furthermore, new product launches are underway or imminent in most of Sanofi s core businesses and several high potential R&D projects progressed in 2013, including alirocumab, sarilumab and U300.

Q4 2013 and 2013 Performance

Sales increased 6.5%(4) in Q4 2013. In 2013, total sales were stable (-0.5%) at 32,951 million.

Growth platforms(3) increased 10.0% in Q4 2013. In 2013, sales from growth platforms reached 23,905 million (+6.6%) and accounted for 72.5% of total sales.

In Q4 2013, Emerging Markets(5) sales recorded double digit growth (+10.4%). In 2013, Emerging Markets sales were 10,957 million, an increase of 4.4% (+7.1% excluding Brazil generics).

Diabetes sales were up 19.0% in Q4 2013. Diabetes recorded strong double digit growth (+18.7%) to 6,568 million in 2013 driven by the performance of Lantus (+20.0% to 5,715 million).

Vaccines sales were stable in Q4 2013 as supply improved for Pentacel and Adacel in the U.S. from mid-October. In 2013, Vaccines sales were stable at 3,716 million as record flu vaccines sales offset U.S. supply constraints on Pentacel and Adacel .

CHC sales were up 6.1% in Q4 2013. Sales of Consumer Healthcare exceeded 3 billion in 2013, an increase of +5.2%.

Genzyme recorded a robust performance in Q4 2013 with sales up 31.4%. In 2013, Genzyme recorded sales of 2,142 million, up 25.9% driven by 16.6% growth of the rare disease franchise and by Aubagio ( 166 million).

Animal Health sales were down 6.3% in Q4 2013. Sales of Animal Health decreased 5.3% to 1,985 million in 2013 reflecting increased competition to Frontline . Broadline , a unique product in the fight against internal and external parasites for cats, was approved in the EU in December.

In Q4 2013, business EPS(1) was 1.37 (+ 30.8% at CER). 2013 business EPS was 5.05 (-9.8% at CER).

Board proposes dividend of 2.80.

In Q4 2013, positive top line results in Phase III trials for U300 (EDITION III, IV and EDITION JP I) and for sarilumab (SARIL-RA-MOBILITY) were announced. The Phase III program for the Fixed-Ratio combination of Lantus /Lyxumia was recently initiated.

The FDA accepted the New Drug Application of Cerdelga (eliglustat) for review and granted it a Priority Review designation.

The continued performance of growth platforms, investments in new product launches and in late-stage pipeline should lead to a 2014 business EPS(1) growth between 4% and 7% at CER, barring major unforeseen adverse events.

(1) See Appendix 8 for definitions of financial indicators; (2) Including impact of transition to IAS 19R; (3) See page 2; (4) Growth in net sales is expressed at constant exchange rates (CER) unless otherwise indicated (see Appendix 8 for a definition); (5) See definition on page 7;

Investor Relations: (+) 33 1 53 77 45 45 - E-mail: IR@sanofi.com - Media Relations: (+) 33 1 53 77 46 46 - E-mail: MR@sanofi.com

Web site: www.sanofi.com

2013 fourth-quarter and full-year sales

Unless otherwise indicated, all sales growth figures in this press release are stated at constant exchange rates(1).

In the fourth quarter of 2013, Sanofi generated sales of 8,457 million, a decrease of 0.8% on a reported basis. Exchange rate movements had a negative effect of 7.3 percentage points largely due to the depreciation of the Japanese Yen, U.S. Dollar, Brazilian Real, Venezuelan Bolivar, Australian Dollar and Russian Ruble against the Euro.

Full-year 2013 sales were 32,951 million, a decrease of 5.7% on a reported basis. Exchange rate movements had an unfavorable effect of 5.2 percentage points mainly driven by the depreciation of the Japanese Yen, U.S. Dollar, Brazilian Real, Venezuelan Bolivar, Australian dollar, South African Rand and Russian Ruble against the Euro.

In the fourth quarter of 2013, sales of the Group s growth platforms reached 6,166 million, an increase of 10.0%, driven by double digit-growth of Emerging Markets (+10.4%), Diabetes (+19.0%), Genzyme (+31.4%) and Innovative Products (+15.7%). The Group s growth platforms accounted for 72.9% of total consolidated sales in the fourth quarter up from 70.4% in the fourth quarter of 2012.

In 2013, growth platforms recorded sales of 23,905 million and accounted for 72.5% of total consolidated sales compared with 67.4% in 2012.

(a) Includes products launched since 2009 which do not belong to the other Growth Platforms listed above: Multaq , Jevtana , Zaltrap , Auvi-Q and Mozobil

(b) World excluding the U.S. and Canada, Western Europe, Japan, Australia and New Zealand

Fourth-quarter sales for the Pharmaceuticals business reached 7,054 million, an increase of 8.4% driven by Diabetes, Genzyme and Generics.

2013 sales for the Pharmaceuticals business were stable at 27,250 million (-0.2%). In 2013, sales lost to generic competition on key legacy products in the U.S. and EU were 1,253 million.

The Diabetes division recorded its twelfth quarter of double-digit growth (up 19.0%) to 1,735 million. Lantus sales were 1,512 million, an increase of 19.9% driven by the U.S. ( 997 million, an increase of 24.1%) and Emerging Markets ( 234 million, an increase of 21.4%).

(1) See Appendix 8 for definitions of financial indicators

In the U.S., Lantus SoloSTAR sales represented 58.0% of total Lantus sales in the quarter, versus 53.4% in the fourth quarter of 2012. Lantus sales in Western Europe were 204 million, an increase of 4.0%. In 2013, sales of Lantus totaled 5,715 million, up 20.0% driven by the U.S. (+25.6%) and Emerging Markets (+16.8% to 874 million).

Sanofi filed a patent infringement suit against Eli Lilly on January 30, 2014 in the United States District Court for the District of Delaware. In its suit Sanofi alleges infringement of four patents. The suit was triggered by notifications received from Lilly starting in mid-December, in which Lilly stated that it had filed a NDA (505(b)(2) New Drug Application) with FDA for an insulin glargine drug product. Lilly also stated that its NDA included a paragraph IV certification challenging six of the seven Sanofi patents listed in the FDA Orange Book for Sanofi s Lantus and Lantus SoloStar products.

Sales of Apidra reached 81 million (up 33.8%) and 288 million (up 31.7%) in the fourth quarter and 2013, respectively.

In the fourth quarter, sales of Amaryl were 91 million, an increase of 2.0%. In Emerging Markets, sales of the product grew 10.8% to 66 million. In 2013, sales of Amaryl were 375 million (-1.0%), reflecting 9.9% growth (to 269 million) in Emerging Markets and generic competition in Japan where sales decreased 18.4% to 81 million.

Lyxumia (lixisenatide), a once-daily prandial GLP-1 receptor agonist is commercialized in several countries in Europe (including the UK, Germany, Spain), Japan and Mexico. Fourth-quarter and 2013 sales of Lyxumia were 5 million and 9 million, respectively.

Full-year sales of the Diabetes division reached 6,568 million, an increase of 18.7%.

Sales of Consumer Healthcare (CHC) products increased 6.1% to 722 million in the fourth-quarter, driven by the U.S. and Emerging Markets. In the U.S., CHC sales grew 11.9% reflecting a strong performance from the Chattem portfolio as well as 9.1% increase in Allegra sales. In Emerging Markets, the performance (+12.6% to 388 million) was sustained by strong growth recorded in Russia (+26.6%). In the fourth quarter of 2013, several CHC flagship brands recorded strong performance: Essentiale (+25.0%), Enterogermina (+30.8%) and No Spa (+23.1%). Full-year sales of CHC totaled 3,004 million, an increase of 5.2%, with seven major brands accounting for 40% of sales.

In September, Sanofi re-introduced the antacid Rolaids to retail stores across the U.S. In October, the U.S. Food and Drug Administration approved Nasacort Allergy 24HR nasal spray as an over-the-counter (OTC) treatment for seasonal and year-round nasal allergies in adults and children 2 years of age and older. Nasacort Allergy 24HR nasal spray was recently introduced in the U.S.

In the fourth quarter of 2013, Genzyme sales grew 31.4% to 595 million driven by the uptake of Aubagio and the performance of rare disease products. Genzyme recorded double digit growth in all regions with +47.4% in the U.S. ( 213 million), +33.6% in Emerging Markets ( 130 million), +21.5% in Western Europe ( 196 million) and +13.6% in the rest of the world ( 56 million). Full-year sales of Genzyme totaled 2,142 million, an increase of 25.9%.

Fourth-quarter sales of Cerezyme , the leading therapy for Gaucher disease, increased 12.9% to 181 million, reflecting new patient accruals and strong growth in Emerging Markets ( 67 million, up 23.3%) and the U.S. ( 44 million, up 11.9%). In Western Europe, sales of the product were 60 million, an increase of 9.1%. In 2013, sales of Cerezyme were 688 million, up 13.9%.

Sales of Myozyme /Lumizyme grew 13.2% to 131 million in the fourth quarter, driven by the addition of new patients. In Emerging Markets, the product continued to deliver strong performance with sales up 53.3% to 21 million. Sales in the U.S. and Western Europe were 31 million (up 13.8%) and 71 million (up 5.9%), respectively. Full-year sales of Myozyme /Lumizyme grew 11.9% to 500 million.

Fourth-quarter sales of Fabrazyme increased 34.5% to 104 million. In Western Europe, sales grew 52.9% to 26 million reflecting market share gains from the competitor product. In the U.S., sales of Fabrazyme were up 13.0% to 49 million, largely due to the addition of new patients. In Emerging Markets, sales of the product doubled reaching 15 million. In 2013, Fabrazyme regained its market leadership with sales of 383 million, up 39.0%.

Sales of Aubagio were 69 million in the fourth quarter of which 55 million were in the U.S. The launch of the product in the first Western European countries (specifically Germany and Scandinavia) started in the fourth quarter and sales reached 12 million. In 2013, sales of Aubagio totaled 166 million.

Following its approval by the European Commission in September, Lemtrada (alemtuzumab, developed in collaboration with Bayer HealthCare to treat relapsing forms of multiple sclerosis) was launched in Germany in October. Fourth-quarter sales of the product were 2 million. Lemtrada is also approved in Canada, Australia, in Nordic countries and Mexico. In December 2013, Genzyme received a Complete Response Letter from the U.S. Food and Drug Administration (FDA) for its supplemental Biologics License Application seeking approval of Lemtrada for the treatment of relapsing forms of multiple sclerosis. Genzyme is preparing its appeal to the agency. The CVR milestone of U.S. approval of Lemtrada by March 31, 2014 will not be met.

Other Innovative Products(6)

(6) Includes new product launches which do not belong to the other Growth Platforms

Sales of Multaq were 71 million (up 15.9%) and 269 million (up 8.2%) in the fourth quarter and 2013, respectively. Jevtana sales increased 13.3% in the fourth quarter to 66 million driven by Western Europe (up 30.8%). In 2013, sales of Jevtana were 231 million (up 1.3%). Sales of Auvi-Q (7) which was launched in the U.S. in January 2013, were 9 million and 51 million in the fourth quarter and 2013, respectively. Fourth-quarter and 2013 sales of Mozobil were 25 million (up 4.0%) and 101 million (up 8.3%), respectively. Sales of Zaltrap (aflibercept, developed in collaboration with Regeneron) were 15 million in the fourth quarter and 53 million in 2013.

Established Pharmaceutical Products

Sales of Plavix increased 12.5% to 491 million in the fourth quarter, driven by China (+39.8% to 114 million) following a market slowdown in the third quarter, and Japan (+15.7% to 209 million). In 2013, sales of Plavix reached 1,857 million, up 1.1%.

Fourth-quarter sales of Lovenox increased 4.1% to 438 million, reflecting 6.7% growth in Western Europe ( 222 million) and generic competition in the U.S. (-3.6% to 51 million). Full-year sales of Lovenox were 1,703 million, a decrease of 7.2%.

Sales of Aprovel /Avapro were 193 million, down 4.2% in the fourth-quarter, reflecting generic competition in Western Europe (-9.3% to 67 million) and strong performance in Emerging Markets (+14.6% to 102 million). In 2013, sales of Aprovel /Avapro decreased 20.9% to 882 million of which 410 million was generated in Emerging Markets (up 9.1%).

Sales of Renvela /Renagel recorded strong growth (+28.8% to 217 million) in the fourth-quarter driven by the U.S. (+39.0% to 163 million). In 2013, sales of Renvela /Renagel were 750 million, up 19.0%.

Fourth-quarter sales of the Ambien family of products were 104 million, an increase of 3.4% despite generic competition in Japan (-8.8% to 48 million). Full-year sales of the Ambien family of products totaled 391 million, down 9.5%.

Sales of Synvisc /Synvisc-One were 99 million (up 14.4%) and 371 million (up 6.1%), in the fourth-quarter and 2013, respectively.

Sales of Taxotere were 103 million in the fourth-quarter, a decrease of 6.4%, reflecting generic competition globally. In 2013, sales of Taxotere were 409 million, down 19.5%.

Fourth-quarter sales of Allegra as a prescription drug decreased 19.3% to 87 million reflecting generic competition in Japan (sales were down 30.5% to 56 million). 2013 sales of Allegra were 406 million, down 12.1%.

Sales of Eloxatin decreased 19.1% to 52 million in the fourth-quarter. Full-year sales of Eloxatin were down 76.0% to 221 million reflecting the loss of the product market exclusivity in the U.S. in August, 2012.

Sales of Generics increased 12.0% to 478 million in the fourth-quarter, reflecting strong improvement in Brazil where sales grew 23.6% ( 59 million). In the U.S., Generics sales decreased 41.0% to 35 million due to reduced sales of the authorized generic of Lovenox and Taxotere . In 2013, sales of Generics were 1,625 million a decrease of 8.2% reflecting challenges in Brazil and lower sales of authorized generics in the U.S. Excluding Brazil, sales of Generics grew 8.6% in 2013.

(8) Sanofi U.S. licensed the North America commercialization rights to Auvi-Q from Intelliject.Inc.

Consolidated sales of Sanofi Pasteur were stable at 959 million the fourth quarter reflecting strong influenza vaccines sales and a progressive supply improvement of Pentacel , Adacel and Daptacel from mid-October in the U.S. Full-year consolidated sales of Sanofi Pasteur were also stable at 3,716 million.

Sales of Polio/Pertussis/Hib vaccines were 341 million, an increase of 5.8%, reflecting progressive improvement of supply for Pentacel in the U.S. and continued strong Pentaxim penetration, coupled with lower sales of Imovax in Japan due to the end of the catch-up cohort following its launch in September 2012. In Emerging Markets, sales of Polio/Pertussis/Hib vaccines grew 36.0%. The rollout of Hexaxim in Emerging Markets continued. Full-year sales of Polio/Pertussis/Hib vaccines totaled 1,148 million, up 3.2%.

Fourth-quarter sales of influenza vaccines grew 94.4% to 198 million. Sales in the U.S. were 121 million (3 times more than in Q4 2012), reflecting a positive phasing of supply and the success of Sanofi Pasteur s differentiation strategy. Differentiated vaccines such as Fluzone High-Dose for elderly people, Fluzone Quadrivalent vaccine, a four-strain influenza vaccine and Fluzone ID (which uses a novel microinjection system for intradermal delivery) represented 41% of flu vaccines sales in the U.S. for Sanofi Pasteur in 2013 (versus 26% in 2012). Full-year sales of influenza vaccines reached of new record level at 929 million, up 9.3%. In the U.S., Flu vaccines sales in 2013 were 533 million, an increase of 20.4%.

Menactra sales were 63 million, a decrease of 64.0% in the fourth-quarter, reflecting a high comparison basis in the fourth quarter of 2012 which included CDC (Centers for Disease Control and Prevention) stock piling in the U.S. and strong sales in Latin America associated with a meningitis outbreak. Full-year sales of Menactra were 424 million, down 21.5%. In the U.S., Menactra maintained a strong market share of 78% in 2013.

Fourth-quarter sales of Adult booster vaccines were 98 million, a decrease of 16.3%, reflecting progressive improvement of supply for Adacel in the U.S. Full-year sales of Adult booster vaccines were 391 million (-18.5%).

Sales of travel and other endemic vaccines reached 109 million, up 10.6%, in the fourth quarter and 382 million, up 9.9%, in 2013, reflecting higher Avaxim sales in Emerging Markets.

Sales of other vaccines were 131 million (up 17.8%) in the fourth quarter and 370 million (up 21.0%) in 2013, respectively, and reflected the expansion of VaxServe (a Sanofi Pasteur company, U.S. supplier of vaccines).

Sales of Sanofi Pasteur MSD (not consolidated), the joint venture with Merck & Co. in Europe were 247 million, an increase of 1.4% (on a reported basis). The rollout of Hexyon (DTaP-IPV-Hib-HepB vaccine) began in Germany and additional launches are expected in 2014. Full-year sales of Sanofi Pasteur MSD increased 3.7% (on a reported basis) to 876 million driven by Gardasil (up 6.7% on a reported basis to 219 million) and the launch of Zostavax ( 51 million).

Fourth-quarter sales of Animal Health products were 444 million, a decrease of 6.3%. Full-year sales of Animal Health products were 1,985 million, down 5.3%.

Sales of the Companion Animals franchise were 218 million, a decrease of 10.0% in the fourth-quarter reflecting increased Frontline competition from prescription-only products and branded generics of fipronil. Full-year sales of the Companion Animals franchise were 1,195 million, down 9.8%.

In September, the U.S. FDA approved NexGard (afoxolaner) Chewables for the treatment and prevention of flea infestations, and treatment and control of the American Dog tick in adult dogs and puppies. The launch of NexGard began in the U.S. in the first quarter of 2014. In December, the European Medicines Agency (EMA) approved Broadline , a unique product in the fight against external and internal parasite for cats and kittens. Broadline will be a prescription-only product and is expected to be launched in Europe in the first quarter of 2014.

Fourth-quarter sales of the Production Animals franchise totaled 226 million, down 2.4%. Full-year sales of the Production Animals franchise were 790 million, an increase of 2.1%.

Net sales by geographic region

(a) World less the U.S., Canada, Western Europe, Japan, Australia and New Zealand

(b) France, Germany, UK, Italy, Spain, Greece, Cyprus, Malta, Belgium, Luxembourg, Portugal, Netherlands, Austria, Switzerland, Sweden, Ireland, Finland, Norway, Iceland, Denmark

(c) Japan, Canada, Australia and New Zealand

Emerging Markets recorded double-digit growth in the fourth quarter to 2,917 million, driven by Diabetes (+19.3%), Genzyme (+33.6%), Generics (+26.8%) and CHC (+12.6%). Fourth-quarter sales in China recorded strong performance (+35.1% to 400 million) reflecting the progressive recovery of the Pharmaceuticals business. Sales in Eastern Europe, Russia and Turkey were up 5.2% to 712 million, driven by Russia (+10.4%) to 250 million, Turkey (+16.0%) and Hungary (+11.5%). Latin America sales increased 10.1% to 825 million. In Brazil, sales grew 6.8% to 337 million driven by the performance of Generics (+23.6%) and Genzyme (+66.7%) despite lower sales of vaccines. Full-year sales in Emerging Markets were 10,957 million, an increase of 4.4% (+7.1% excluding Brazil Generics). Full-year sales in China, Brazil and Russia were 1,471 million (+18.6%), 1,111 million (-18.2%) and 901 million (+12.0%), respectively.

Sales trends in the U.S. have been gradually improving in recent quarters Fourth-quarter sales in the U.S. delivered 12.3% growth to 2,654 million driven by strong performances from Diabetes (up 24.9%), Genzyme (up 47.4%) and CHC (up 11.9%). Full-year sales in the U.S. were 10,433 million, down 0.7%.

Sales trends in Western Europe have also been gradually improving in recent quarters. In the fourth quarter sales in this region were 1,943 million, an increase of 1.2%, reflecting the impact of austerity measures, generic competition and 9.2% growth in Germany which benefited from the launch of Aubagio and Lemtrada . Full-year sales in Western Europe totaled 7,831 million, down 5.6%.

Sales in Japan were 650 million, a decrease of 8.4% in the fourth quarter primarily reflecting the impact of generic competition to Allegra , Myslee , Amaryl and lower sales of the active ingredient of Aprovel to local partners as well as lower sales of Imovax Polio. In 2013, sales in Japan were 2,507 million, down 4.3%.

Consult Appendix 5 for full overview of Sanofi s R&D pipeline

Regulatory updates since the publication of the third-quarter 2013 results on October 30, 2013 include the following:

In December, Sanofi and its subsidiary Genzyme announced that it received a Complete Response Letter from the U.S. Food and Drug Administration (FDA) for its supplemental Biologics License Application seeking approval of LemtradaTM (alemtuzumab) for the treatment of relapsing forms of multiple sclerosis. Genzyme is preparing its appeal to the agency.

In December the FDA granted a Priority Review designation to the New Drug Application (NDA) for Cerdelga (eliglustat), an investigational oral therapy for adult patients with Gaucher disease type 1. The European Medicines Agency (EMA) accepted Genzyme s marketing authorization application for eliglustat in the EU in late October 2013.

In December, Merial announced the approval by the European Medicines Agency of Broadline , a unique product in the fight against external and internal parasite for cats and kittens.

Sanofi Pasteur made the decision to withdraw the Quadrivalent Influenza Vaccine marketing authorization application submitted in Europe through a decentralized procedure early this year to update the pharmaceutical section at the request of the regulatory authorities. Sanofi Pasteur will take the opportunity of this update to extend the target group to 36 month of age (vs. 9 years of age in the initial submission). A phase III study will start in 2014 with the objective of providing the necessary data.

At the beginning of February 2014, the R&D pipeline contained 49 projects (excluding Life Cycle Management) and vaccine candidates in clinical development of which 12 are in Phase III or have been submitted to the health authorities for approval. Biologics constitute 80% of pipeline projects(8) in development. Sanofi currently has nine high-potential late-stage projects(9).

The Phase III program for LixiLan, the Fixed-Ratio combination of Lantus / Lyxumia , started. LixiLan-O will evaluate LixILan in patients insufficiently controlled on oral antidiabetics drugs (OADs) and LixiLan-L will evaluate LixiLan in patients not at goal on basal insulin.

Patisiran (SAR438027/ALN-TTR02), a mRNA inhibitor, entered into Phase III, for familial amyloid polyneuropathy.