Doxycycline hydrochloride is widely used in the medical field as an antibiotic to treat a variety of bacterial infections. It is effective against respiratory tract infections, urinary tract infections, and skin infections. Additionally, it is used to manage sexually transmitted diseases like chlamydia and gonorrhea.

In veterinary medicine, it is commonly prescribed for animals to treat infections caused by susceptible bacteria. It is also utilized in the prevention of malaria for travelers visiting regions where the disease is prevalent.

Beyond its antimicrobial uses, doxycycline hydrochloride is employed in the treatment of acne and rosacea due to its anti-inflammatory properties. It is also used in the management of periodontal disease to reduce bacterial growth and inflammation in the gums.

In research, it serves as a tool in molecular biology for regulating gene expression in inducible gene expression systems. Its broad-spectrum activity and versatility make it a valuable compound in both clinical and scientific applications.