How Clomiphene and Letrozole Help Fertility
At Fertilite, we’re specialists in guiding you on your path to parenthood. Many women with irregular cycles or no ovulation wonder which option is best to stimulate ovulation and achieve pregnancy.
Two of the most widely used medications for ovulation induction are clomiphene citrate and letrozole. In this article we break down how they work and what their differences are.
What These Medications Do
At Fertilite we design personalized protocols for every patient. Both clomiphene and letrozole aim to stimulate the ovaries to release an egg — but they work in different ways:
Clomiphene is a selective estrogen receptor modulator. It temporarily blocks estrogen receptors in the hypothalamus, “tricking” the brain into producing more FSH and LH, which stimulates the ovaries.
Letrozole is an aromatase inhibitor. It lowers the conversion of androgens to estrogens, reducing the negative feedback on the hypothalamic-pituitary axis and increasing FSH to induce ovulation.
In simple terms, both “wake up” the ovary, but via different mechanisms.
Effectiveness and Pregnancy Rates
Recent studies, such as PPCOS II, have shown that letrozole achieves higher ovulation and pregnancy rates than clomiphene in women with polycystic ovary syndrome (PCOS).
However, clomiphene remains very useful in women without PCOS or where letrozole isn’t available. At Fertilite we typically start with the option best suited to your history before moving to other fertility treatments.
How They’re Taken
Clomiphene: 50 mg daily from day 3 to day 7 of the cycle. If there’s no response, the dose can be increased to 100–150 mg under medical supervision.
Letrozole: 2.5–5 mg daily from day 3 to day 7 of the cycle; the dose is adjusted according to response.
At Fertilite, every ovulation induction is accompanied by ultrasound monitoring to measure ovarian response, optimize outcomes, and reduce risks.
Side Effects
Clomiphene: may cause hot flashes, visual disturbances, mood changes, thinning of the endometrium and less favorable cervical mucus; also a higher chance of multiple pregnancy.
Letrozole: hot flashes, dizziness, fatigue, headache; but fewer adverse effects on the endometrium and a lower rate of multiple pregnancies.
In many countries, using letrozole for ovulation induction is considered “off-label,” but strong scientific evidence supports its safety and effectiveness.
At Fertilite we understand every woman is unique. That’s why, when deciding between clomiphene and letrozole, we assess your medical history, hormone tests and reproductive goals to choose the safest and most effective option for you.
With a well-designed protocol, ovulation induction can be a successful first step toward the pregnancy you’re hoping for.
If you’re searching for fertility treatments in Tijuana or want to know more about ovulation induction with clomiphene and letrozole, book an appointment at Fertilite so our specialists can evaluate your case and guide you through your journey.
📞 Phone (Mexico): +52 664 316 6488
📞 Phone (USA): +1 619 586 7830