Using the Fertility Drugs Clomid, Letrozole and Gonadotropins
Oral Fertility Drugs
Oral drugs we use at Fertility Medical Specialists Group are clomiphene citrate (brand name Clomid and Serophene) and letrozole (Femara). Clomid is approved by the Food and Drug Administration for ovulation induction. Letrozole is a drug to treat breast cancer but it also promotes ovulation, so fertility specialists use it for this purpose.
Clomid works by blocking estrogen’s function in the brain, causing it to signal the pituitary gland to produce more FSH and LH, resulting in ovulation. Letrozole causes the ovary to make less estrogen, which has the same effect in increasing FSH and LH.
We generally begin with the lowest dose of these fertility drugs that will result in ovulation and increase the dose as needed. With Clomid, the dose begins at 50-100 mg given for five consecutive days, starting on the second to the fifth day of the menstrual cycle. If ovulation is not occurring, the dose can be increased in increments, generally topping out at 200 mg. Other fertility drugs may be used in conjunction with Clomid.
Letrozole is usually given in 2.5-5 mg doses for five days, beginning on the second to the fifth day of the menstrual cycle. Patients with PCOS who have diabetes or prediabetes may be given the insulin-sensitizing medication metformin.
About 80% of women who are screened as good candidates and who are not ovulating will ovulate taking clomiphene citrate (Clomid), according to ASRM. Letrozole and Clomid have similar pregnancy success rates. Letrozole has been shown to be more effective in helping women with PCOS.