Progestin Injection

Category: Hormonal therapy / Synthetic progesterone
Form: Injectable solution (intramuscular or subcutaneous)

Uses:

• Contraception: long-acting birth control, e.g., depot medroxyprogesterone acetate (DMPA).

• Menstrual disorders: abnormal uterine bleeding, amenorrhea.

• Endometriosis: reduces growth of endometrial tissue.

• Hormone replacement therapy: part of therapy for postmenopausal women to counter estrogen effects on the endometrium.

• Certain cancers: sometimes used in hormone-responsive cancers like endometrial or breast cancer.

Mechanism of Action:

• Mimics natural progesterone, binding to progesterone receptors.

• Suppresses ovulation by inhibiting the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

• Alters cervical mucus, making it hostile to sperm.

• Changes endometrial lining, reducing implantation potential.

• Reduces growth of endometrial tissue, helpful in endometriosis and hormone-dependent cancers.

Administration:

• Given intramuscularly or subcutaneously, usually every 1–3 months depending on formulation.

• Dosage and frequency depend on indication and specific progestin type.

Side Effects:

• Menstrual changes: irregular bleeding, spotting, or amenorrhea.

• Weight changes, bloating, mood swings, headaches.

• Injection site reactions: pain, swelling.

• Rare: bone density reduction with long-term use (mainly DMPA), blood clots in susceptible individuals.

Precautions:

• Assess for history of thromboembolic disorders, liver disease, or hormone-sensitive cancers.

• Consider bone health monitoring during long-term therapy.

• Not immediately reversible in long-acting formulations; fertility may be delayed after discontinuation.

Summary:
Progestin Injection is a synthetic hormone therapy used for contraception, menstrual regulation, endometriosis, and certain hormone-responsive cancers. It works by mimicking natural progesterone to suppress ovulation, alter cervical mucus, and modify the endometrium. Administered intramuscularly or subcutaneously, it can cause menstrual changes, mood or weight changes, and, rarely, bone density reduction or thromboembolic events.