Net sales up 10.1% and Business net income 1 up 4.1% at CER 2 - Performance driven by growth platforms, Genzyme acquisition and cost savings - Q3 2011 Change on a reported basis Change at constant exchange rates 9 months

Net sales up 10.1% and Business net income1 up 4.1% at

- Performance driven by growth platforms, Genzyme acquisition and cost savings -

In order to facilitate an understanding of our operational performance, we comment on our business

net income statement. Business net income1 is a non-GAAP

financial measure. The consolidated income statement for the first 9 months of 2011 is provided in Appendix 7. A reconciliation of business net income to consolidated net income is provided in Appendix 6. Consolidated net income for the first 9

months of 2011 was 4,254 million, compared to 5,030 million for the first 9 months of 2010. Consolidated EPS for the first 9 months of 2011 was 3.23.versus 3.85 for the first 9 months of 2010.

Commenting on the Group s performance in Q3 2011, Sanofi Chief Executive

Officer, Christopher A. Viehbacher said, The return to growth in sales and earnings in the third quarter reflects an important milestone as the company progressively puts the patent cliff behind it. The integration of Genzyme is progressing

well. Our growth platforms3 again achieved double digit growth

and more than compensated for generic erosion. We continue to make strong progress in R&D with the submission of five new products and also in the tight control of our costs.

Sanofi : www.sanofi.com

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

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

2011 third quarter and 9-month net sales

Unless otherwise indicated, all sales growth figures in this press release are

stated at constant exchange rates1.

Net sales in the third quarter of 2011 were 8,753 million, an increase of 5.0% on a reported basis. Exchange rate

movements had a negative effect of 5.1 percentage points, mainly due to a less favorable euro/U.S. dollar parity. Various currencies from Emerging Markets (notably the Venezuelan Bolivar and Turkish Lira) also had an unfavorable impact. At constant

exchange rates, and including changes in structure (primarily the consolidation of Genzyme from

April 1st), net sales increased by 10.1%.

In the first 9 months of 2011, net sales were 24,881 million, up 1.4% on a reported basis. Exchange rate movements had an

unfavorable effect of 2.7 percentage points. The impact of the depreciation of the U.S. dollar, Venezuelan Bolivar and Turkish Lira against the Euro was reduced by the favorable effect of the Japanese Yen and Australian dollar. At constant exchange

rates, and accounting for changes in structure (primarily the consolidation of Genzyme from April 1st), net sales increased by 4.1%.

Growth Platforms (see Appendix 4)

Third-quarter sales of the Group s growth platforms grew by 10.4% or 11.1% excluding A/H1N1 vaccines sales. Including Genzyme, the Group s

growth platforms accounted for 68.5% of total consolidated sales, which is up from 60.2% in the third quarter of 2010. In the first 9 months, the growth platforms and Genzyme comprised 64.5% of total consolidated sales compared with 56.4% over the

same period of 2010. Year-to-date sales growth of growth platforms was 11.9% excluding A/H1N1 vaccines sales.

Pharmaceuticals net sales reached 6,940 million (up 10.0%) in the third quarter, which reflects the

positive contribution ( 768 million) from Genzyme (consolidated from April 1st, 2011) as well as generic competition to Lovenox ,

Ambien CR and Taxotere in the U.S.,

Plavix and Taxotere in the EU and the impact of U.S. healthcare reform and EU austerity measures. Year-to-date 2011 net sales were 20,670 million, an increase of 5.5%.

Third-quarter sales of the Diabetes division grew 12.4% to 1,161 million reflecting strong growth of Lantus in the U.S. (+14.6% to 580 million) and Emerging Markets (+23.4% to 149 million). In Western Europe, Lantus sales increased by 7.1% ( 182 million). In the third quarter, Lantus SoloSTAR represented 47.2% of total

Lantus sales in the U.S., an increase of 14.9 percentage points versus the fourth quarter of 2009. The

growth of Lantus in Japan (+15.1%) was also strong. In Emerging Markets, sales of Lantus doubled in China (+103.5%) and benefited from the inclusion into the reimbursement scheme of the largest

provincial markets, Shanghai (December 2010) and Beijing (July 2011). In Latin America, sales of Lantus were up

31.4%. Year-to-date sales of Lantus reached 2,862 million, up 14.1%.

Net sales of the rapid-acting insulin analog Apidra were 53 million in the third quarter, up 22.2%. Sales in the U.S. increased by 40% ( 20 million) reflecting the benefit of our new commercial

approach. Year-to-date net sales of Apidra reached 155 million, an increase of 24.2%. A

temporary shortage of Apidra 3mL cartridges, will impact supplies potentially until early 2012 in some

markets. Apidra vials are not impacted.

Despite 10.9% growth in Emerging Markets, net sales of Amaryl decreased 7.4% (to 106 million) due to generic competition in Japan. Year-to-date sales of Amaryl were 323 million, down 7.6%.

sales of the Diabetes division increased by 11.8% to 3,442 million.

achieved net sales of 310 million (up 179.2%) in the third quarter, reflecting the full recovery of U.S. sales ( 245 million, versus 56 million in the third quarter of 2010). Year-to-date sales of the

product were 746 million, an increase of 182.9%. In September, the U.S. District Court for the District of New Jersey ruled against Sun Pharmaceuticals in favor of Sanofi U.S. with respect to a contractual dispute arising from the

resolution of the Eloxatin patent litigation. This ruling, which Sun Pharmaceuticals is contesting, maintains

the U.S. market exclusivity of Eloxatin through August 9, 2012.

As expected, net sales of Taxotere decreased by 64.8% to 186 million in the third quarter reflecting generic erosion in the U.S. (sales down 85.3% to 27 million) and in Western Europe

(sales down 78.4% to 41 million). Year-to-date sales of Taxotere were 772 million, down

54.1%. Over the period, Taxotere sales generated outside the U.S. and Western Europe amounted to 377 million.

Third-quarter net sales of Jevtana were 45 million. Sales in the U.S. and in Western Europe reached 26 million and 15 million, respectively. Commercialization of

Jevtana is now underway in most Western European countries. Year-to-date sales of Jevtana were 141 million.

presence1 of Plavix /Iscover

The worldwide presence of

Plavix was 1,738 million, up 6.5%, in the third quarter. Sales in the U.S. (consolidated by

Bristol-Myers Squibb) were 1,185 million, up 9.0%. In Japan and China, Plavix continued to show

strong growth of 20.1% (to 162 million) and 28.5% (to 72 million), respectively. Sales in Europe declined by 21.0% to 143 million, due to generic competition. In the first 9 months of 2011, the worldwide presence of Plavix totaled 5,240 million, an increase of 6.1%. Year-to-date consolidated sales in Japan and China were

463 (up 23.0%) and 203 million (up 29.1%), respectively. On October 18, 2011, in the damages phase of the Plavix patent infringement case against Apotex, the U.S. Court of Appeals upheld the damages award granted to Sanofi and BMS in the amount of $442.2 million.

Worldwide presence of Plavix /Iscover : geographic split

Worldwide presence1 of Aprovel /Avapro /Karvea /Avalide

The worldwide presence of

Aprovel was 434 million, down 15.2% in the third quarter reflecting the growing penetration

of Losartan generics. In the first 9 months of 2011, the worldwide presence of Aprovel totaled

1,384 million, a decrease of 11.0%. Year-to-date consolidated sales of the product in Emerging Markets reached 276 million, up 8.6%.

Worldwide presence of Aprovel /Avapro /Karvea : geographic split

Other Pharmaceutical Products

Third quarter net sales of Lovenox ( 494 million, down

12.7%) were impacted by generic competition in the U.S. ( 133 million, down 42.4%). Lovenox continued to

show solid performance outside the U.S. with a sales increase of 8.7% in Western Europe (to 199 million) and 11.6% in Emerging Markets (to 137 million). Year-to-date sales of Lovenox were 1,613 million, down 26.1%. Sales generated outside the U.S. were 1,098 million (up 8.3%), or 68.1% of total Lovenox sales. In September

2011, the FDA approved Amphastar Pharmaceuticals version of enoxaparin. In October, Sanofi, through its generic business Winthrop, launched an authorized generic of Lovenox in the U.S.

Net sales of Multaq reached 66 million in the third quarter, of which 46 million was generated in the U.S. and

17 million in Western Europe. Year-to-date sales of Multaq were 197 million. Following

its review, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) confirmed in September that the benefits of Multaq continue to outweigh the risks with a revised indication for the treatment of a newly defined population of paroxysmal and persistent Atrial Fibrillation

patients. Multaq is indicated for the maintenance of sinus rhythm after successful cardioversion in

adult clinically stable patients with paroxysmal or persistent atrial fibrillation. Due to its safety profile,

Multaq should only be prescribed after alternative treatment options have been considered and should not

be given to patients with left ventricular systolic dysfunction or to patients with current or previous episodes of heart failure. The benefit/risk assessment of Multaq by other regulatory agencies is ongoing.

Third-quarter net sales of the Ambien family of products

decreased by 43.6% (to 121 million), due to generic competition to Ambien CR in the U.S. (Ambien sales in the U.S. were down 81.0%). In Japan, Myslee , showed 7.3% growth to 69 million in the third quarter. Year-to-date sales of the Ambien family were 353 million of which 64 million was for Ambien CR in the U.S.

(Ambien sales in the U.S. were down 82.5%). Year-to-date sales of Myslee in Japan totaled 198 million, up 9.5%.

Third quarter net sales of Allegra as a prescription drug, were 103 million of which 75 million (up 4.0%) was generated in Japan. Allegra moved to the OTC market in the U.S. in March 2011 (sales reported in CHC). Year-to-date sales of Allegra as a prescription drug, were 438 million, 80% of which ( 349 million) was generated in Japan and

Net sales of Copaxone were 117 million, down 6.4% in the third-quarter, reflecting the end of the co-promotion agreement in certain countries notably the U.K in the fourth

quarter of 2010. Year-to-date sales of the product reached 350 million, down 10.1%.

Third quarter sales of Genzyme reached 768 million, an increase of 6.9% over the third quarter of 2010.

Net sales of Cerezyme were 141 million in the third quarter, an increase of 7.0%. Quarterly sales were impacted by reduced product availability during the quarter.

Net sales of Myozyme /Lumizyme were

101 million, an increase of 27.2%. Growth in the third quarter was driven by continued expansion of

Lumizyme in the U.S. and volume growth across all geographies.

Net sales of Fabrazyme in the third quarter were 32 million, up 24.9% from the third quarter of 2010. The increase was driven by greater availability of the product compared

to the third quarter of 2010.

Sales of Renvela /Renagel were

135 million in the third quarter, an increase of 6.7%. Growth in the third quarter was driven by continued U.S. market share growth, which reached an all time high of 53.1% in September, and European adoption of Renvela , particularly in the chronic kidney disease segment.

Net sales of Synvisc /Synvisc One were

80 million, up 11.3% due to continued growth in the U.S. and in Japan.

Genzyme announced in early October that

a temporary decrease in Cerezyme production yields, and changes to product release processes and