Injectable Fertility Medications: FSH, LH, and hMG

When oral fertility medications like Clomid or Letrozole aren't sufficient, or when more precise control over ovarian stimulation is needed, injectable fertility medications provide a more direct and powerful approach to stimulating egg development. These medications contain the actual hormones that stimulate the ovaries, bypassing the brain's signaling system entirely.

Injectable gonadotropins are purified versions of the same hormones your body naturally produces to stimulate ovulation. FSH (follicle-stimulating hormone) promotes the growth and development of multiple follicles, while LH (luteinizing hormone) triggers the final maturation and release of eggs. hMG (human menopausal gonadotropin) contains both FSH and LH activities.

These medications are derived from either the urine of postmenopausal women (traditional source) or produced using recombinant DNA technology in laboratory settings. Recombinant products (like Gonal-F, Follistim, and Ovidrel) are highly purified and consistent, while urinary-derived products (like Menopur and Pregnyl) contain additional proteins that may provide benefits in some situations.

The injectable medication protocol is more complex than oral medications, typically requiring daily injections for 8-12 days during the follicular phase of your cycle. Treatment usually begins on cycle day 2 or 3 and continues until follicles reach appropriate size for triggering ovulation, as determined by ultrasound monitoring and blood hormone levels.

Dosing for injectable medications is highly individualized based on factors like age, weight, ovarian reserve tests (AMH, FSH), and previous response to fertility treatments. Starting doses typically range from 75-300 IU daily, with adjustments made based on your ovarian response as monitored through blood tests and ultrasounds every 2-3 days.

The goal of injectable medication cycles is controlled ovarian stimulation – developing multiple mature follicles while avoiding overstimulation that could be dangerous. Most protocols aim for 2-4 mature follicles for IUI cycles or 8-15 follicles for IVF cycles, though individual responses vary significantly.

Monitoring during injectable cycles is intensive and essential for both safety and success. You'll typically have blood tests and ultrasounds every 2-3 days once treatment begins, allowing your doctor to track follicle development, measure estrogen levels, and adjust medication doses as needed. This close monitoring helps optimize outcomes while preventing dangerous overstimulation.

The "trigger shot" represents the final step in most injectable medication cycles. Once follicles reach appropriate size (usually 18-20mm in diameter), an injection of hCG (human chorionic gonadotropin) or Lupron is given to trigger final egg maturation and ovulation. This shot precisely times ovulation, typically occurring 36-40 hours later.

Success rates with injectable medications are generally higher than with oral medications, particularly for women who don't respond well to Clomid or Letrozole. Pregnancy rates of 15-25% per IUI cycle and 30-50% per IVF cycle are typical, though rates vary significantly based on age, diagnosis, and individual response to treatment.

The complexity and cost of injectable medications mean they're typically reserved for specific situations: women who don't ovulate with oral medications, those preparing for IUI or IVF, women with unexplained infertility who need more aggressive treatment, or those requiring precise timing for procedures.

Side effects of injectable medications can be more significant than oral medications due to the higher hormone levels achieved. Common effects include bloating, breast tenderness, mood changes, fatigue, and injection site reactions. More serious risks include ovarian hyperstimulation syndrome (OHSS), which requires careful monitoring and management.