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HCG (Fertility) (HCG for Ovulation Trigger (Pregnyl/Ovidrel))

Category: Fertility. Status: FDA Approved.

Used as an ovulation trigger in assisted reproduction protocols. The LH-mimicking activity of HCG causes final oocyte maturation and ovulation approximately 36 hours after injection, timing intercourse or egg retrieval.

How it works

Binds LH/CG receptors on the dominant follicle, triggering resumption of meiosis in the oocyte, luteinization of granulosa cells, and follicular rupture (ovulation) within 36-40 hours of administration.

Key facts

  • Molecular weight: ~36,700 Da
  • Half-life: ~33 hours
  • Bioavailability: ~100% (subcutaneous/intramuscular)
  • Storage: Refrigerate. Reconstituted: use within 30 days.

Dosing overview

  • Typical dose: 5000-10,000 IU (Pregnyl) or 250 mcg (Ovidrel)
  • Frequency: Single injection timed to follicle maturity
  • Duration: Per cycle
  • Route: Subcutaneous or intramuscular

Reported benefits

  • Precise ovulation timing
  • Final oocyte maturation
  • Corpus luteum support
  • IUI/IVF timing coordination
  • Luteal phase support

Possible side effects

  • Ovarian hyperstimulation risk
  • Bloating
  • Breast tenderness
  • Mood changes
  • Pelvic discomfort
  • Multiple pregnancy risk

Research

  • HCG trigger timing in IUI cycles (2021): HCG trigger at 18mm follicle size optimized pregnancy rates (22% per cycle) vs earlier or later trigger timing.
  • Dual trigger (GnRH agonist + low-dose HCG) (2022): Dual trigger reduced OHSS incidence by 90% while maintaining equivalent oocyte yield in high-responder IVF patients.

Compare HCG (Fertility)

Research and educational reference only. Not medical advice.