Gestmarck 400 Soft Gelatin Capsule contains 400 mg of natural micronized progesterone, a bioidentical hormone essential for regulating various physiological functions related to the female reproductive system. Progesterone plays a critical role in the menstrual cycle, supporting the luteal phase and maintaining pregnancy by preparing the endometrium for implantation and reducing uterine contractions. Gestmarck 400 is indicated for hormone replacement therapy in conditions associated with progesterone deficiency, such as amenorrhea, abnormal uterine bleeding, and luteal phase support in assisted reproductive technologies. It is also used in the management of menopausal symptoms when combined with estrogen to reduce the risk of endometrial hyperplasia. The natural micronized form enhances absorption and bioavailability, ensuring effective plasma levels. Administration should be guided by a healthcare professional, with dosage tailored to individual clinical needs. Common side effects may include dizziness, headache, breast tenderness, and mild gastrointestinal disturbances. Contraindications include known hypersensitivity to progesterone, unexplained vaginal bleeding, active thromboembolic disorders, and certain hormone-sensitive cancers. Regular monitoring is advised during therapy to assess efficacy and detect adverse effects. Gestmarck 400 Soft Gelatin Capsule offers a reliable option for restoring hormonal balance in women requiring progesterone supplementation.