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

June 25, 2026

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,

This is to inform you that the United States Food & Drug Administration (USFDA) today completed a Pre-License Inspection (PLI) at our biologics manufacturing facility in Bachupally, Hyderabad. The inspection was conducted between June 16 and June 25, 2026. We have been issued a Form 483 with seven observations, which we will address within the stipulated timeline. This is also in continuation of the earlier inspections and corresponding disclosures made to the stock exchanges on October 12, 2023 and September 13, 2025.

This is for your information and records.

Thanking you,

Yours faithfully,

For Dr. Reddy’s Laboratories Limited

K Randhir Singh

Company Secretary, Compliance Officer & Head-CSR