📋 Clinical Overview

Recombinant follicle stimulating hormone (rFSH) is a highly purified, non-urinary derived gonadotropin produced by recombinant DNA technology in Chinese Hamster Ovary (CHO) cells. It is structurally and functionally identical to endogenous human FSH, consisting of two non-covalently linked, glycosylated subunits (alpha and beta). It is a critical agent in controlled ovarian stimulation (COS) protocols for assisted reproductive technology (ART) and for ovulation induction in anovulatory women. In the Indian context, it is a cornerstone of infertility treatment, available in both vial and pen injector forms.

💊 Dosage & Administration

Adult: HIGHLY INDIVIDUALIZED. **Ovulation Induction:** Starting dose is typically 75-150 IU SC daily, adjusted based on response. **ART (IVF/ICSI):** Starting dose ranges from 150-300 IU daily, often in combination with other hormones (GnRH agonists/antagonists). The 75IU vial is used for precise dose titration.

Note: For subcutaneous injection into the abdominal wall or anterior thigh. Rotate injection sites. Reconstitute the lyophilized powder with the provided solvent (if using vial). Pre-filled pens are also available. Administer at approximately the same time each day. Strict aseptic technique must be followed.

⚠️ Contraindications

Hypersensitivity to recombinant FSH or any excipient.
Tumors of the ovary, breast, uterus, pituitary, or hypothalamus.
Undiagnosed vaginal bleeding.
Primary ovarian failure.
Ovarian cysts or enlargement not due to Polycystic Ovary Syndrome.
Pregnancy (except in controlled ART settings where the goal is pregnancy).

🔬 Mechanism of Action

Recombinant FSH binds to specific FSH receptors located on the granulosa cells of the ovarian follicles. This binding activates the adenylate cyclase system, increasing intracellular cAMP. This cascade stimulates follicular growth and maturation, promotes aromatase activity for the conversion of androgens to estrogens (primarily estradiol), and increases inhibin B production.

🤕 Side Effects

Injection site reactions (pain, redness, bruising).
Headache.
Mild to moderate ovarian enlargement with abdominal pain/discomfort.
Nausea.
Breast tenderness.

🤰 Special Populations

Pregnancy: **Category X.** Contraindicated in established pregnancy except in the very specific context of ART where pregnancy is the desired outcome of treatment. Treatment is discontinued once pregnancy is confirmed via hCG trigger. May increase risk of multiple gestation.

Driving: No known effects. However, side effects like headache or dizziness could impair ability.

🔄 Drug Interactions

Clomiphene Citrate	May have synergistic effect, increasing follicular response and OHSS risk.	Moderate
GnRH Agonists (e.g., Leuprolide)	Used in combination for pituitary down-regulation in ART cycles. Synergistic.	Low (managed protocol)
GnRH Antagonists (e.g., Cetrorelix, Ganirelix)	Used in combination to prevent premature LH surge. No significant PK interaction.	Low (managed protocol)
hCG (Human Chorionic Gonadotropin)	Used to trigger final oocyte maturation after FSH stimulation. Sequential use is standard.	Low (managed protocol)

Ovufollin