Exhibit 99.1

Dr. Reddy's Laboratories Ltd. 8-2-337, Road No. 3, Banjara Hills Hyderabad – 500 034, Telangana, India CIN: L85195TG1984PLC004507 Tel:      + 91 40 4900 2900 Fax:     + 91 40 4900 2999 Email: mail@drreddys.com Web:   www.drreddys.com

September 13, 2025

National Stock Exchange of India Ltd. (Scrip Code: DRREDDY)

BSE Limited (Scrip Code: 500124)

New York Stock Exchange Inc. (Stock Code: RDY)

NSE IFSC Ltd. (Stock Code: DRREDDY)

Dear Sir/Madam,

Ref: Disclosure under Regulation 30 of the SEBI (Listing Obligations and Disclosure Requirements) Regulations, 2015

This is to inform you that the United States Food & Drug Administration (USFDA) on September 12, 2025, completed a Pre-Approval Inspection (PAI) at our biologics manufacturing facility in Bachupally, Hyderabad. The inspection was conducted from September 4, 2025 to September 12, 2025. We have been issued a Form 483 with five observations, which we will address within the stipulated timeline. This is pursuant to the inspection conducted earlier and disclosure made to the stock exchanges on October 12, 2023.

This is for your information and record.

Thanking you.

Yours faithfully,

For Dr. Reddy’s Laboratories Limited

  

K Randhir Singh

Company Secretary, Compliance Officer & Head-CSR