Short answer: Yes. Ovarian enlargement was the most common side effect in the clomiphene label's trials, at 13.6% of over 8,000 women, and cysts can form. The label says they usually shrink on their own within days or weeks after stopping, and the next course waits until the ovaries are back to their usual size. It also says prolonged use may raise the risk of a borderline or invasive ovarian tumor.
Clomid (clomiphene citrate) is taken for 5 days to bring on ovulation, and the label notes the ovary can enlarge as follicles grow, whether the enlargement is normal or abnormal. In the label's trials of 8,029 women, the side effects above 1% were:
| Side effect | Share of women |
|---|---|
| Ovarian enlargement | 13.6% |
| Hot flashes | 10.4% |
| Belly or pelvic discomfort, swelling or bloating | 5.5% |
| Nausea and vomiting | 2.2% |
| Breast discomfort | 2.1% |
| Visual symptoms | 1.5% |
After approval, ovarian cysts, ovarian bleeding and twisting of an enlarged ovary or cyst (adnexal torsion) were also reported.
The label starts treatment at 50 mg a day for 5 days and advises the lowest dose that works, since some women with polycystic ovary syndrome respond strongly. See PCOS.
The label says to tell the physician about any belly or pelvic pain, weight gain, discomfort or swelling after taking clomiphene. MedlinePlus lists stomach or lower stomach pain, stomach swelling, weight gain and shortness of breath as uncommon symptoms that call for a prompt call. Severe swelling with fluid buildup is a sign of ovarian hyperstimulation syndrome, which the label treats as separate from simple enlargement.
The label says prolonged use may increase the risk of a borderline or invasive ovarian tumor, and that infertility itself is a primary risk factor. It does not recommend long-term cyclic therapy beyond about six cycles. A 2019 Cochrane review of 37 studies found some studies suggesting a slight rise, higher for borderline tumors and in women who never became pregnant, but rated all the evidence very low certainty because cancers were few.
Dose Track can log each course by cycle day with the dose, which keeps the cycle count clear for clinic visits.
Read more on Dose Track: Clomid side effects · Clomid dosing schedule · Letrozole vs Clomid · Ovulation induction