Clomiphene: what it treats, how to take it, side effects
Last updated September 3, 2026.
Clomiphene is an ovulatory stimulant - it works like estrogen's signal to get eggs developing in the ovaries and released. You may know it as Clomid. It is usually the first medication tried for infertility caused by absent ovulation, taken in five-day monthly bursts under a doctor's timing.
What does it treat?
Infertility in women who do not produce eggs but wish to become pregnant. It induces ovulation; it does not treat other causes of infertility.
How do you take it?
One tablet daily for 5 days, beginning on or about day 5 of the cycle - the calendar is the prescriber's, and it is precise, because the drug must land before the ovary's selection window. Same time each day, exactly as directed. Clomiphene should not be used for more than about six cycles - long-term use may increase the risk of ovarian cancer, and if it has not worked by then, a different approach is due. Missed dose: call the prescriber - in a 5-day cycle-timed course, timing is everything and improvisation breaks the cycle.
Side effects to know
- Common: flushing and warmth, upset stomach, vomiting, breast discomfort, headache, and abnormal vaginal bleeding.
- Serious - uncommon, but call your doctor immediately: blurred vision, visual spots or flashes, and double vision; stomach or lower-stomach pain, stomach swelling, weight gain, and shortness of breath - the ovarian hyperstimulation pattern.
Who should not take it?
Flag liver disease, ovarian cysts (except the polycystic-ovary kind), uterine fibroids, abnormal vaginal bleeding, pituitary tumor, and thyroid or adrenal disease before starting. If you are pregnant or become pregnant while taking it, call immediately. Vision effects mean no driving until you know how it affects you, especially in poor lighting. And the odds conversation belongs up front: clomiphene increases the chance of twins or more.
When is it an emergency?
Severe abdominal pain with swelling, rapid weight gain, and shortness of breath - hyperstimulation - is urgent care. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
What a Pymander AI doctor consult looks like
Illustrative example, not a real member's messages.
Common questions
Why is clomiphene limited to about six cycles?
Two reasons stack: long-term use may increase the risk of ovarian cancer - MedlinePlus says it plainly - and the practical logic that if ovulation-plus-timing has not produced a pregnancy after several well-run cycles, the missing piece is probably something clomiphene cannot fix. Six cycles is where the label draws the line, and it doubles as the natural decision point for the next step in care.
Why did my doctor mention twins before prescribing it?
Clomiphene stimulates the ovaries toward releasing eggs - sometimes more than one. MedlinePlus tells users directly that it increases the chance of multiple pregnancy and to discuss the risks. Multiples raise the stakes of the pregnancy itself - preterm birth, complications - so it belongs in the up-front conversation, not the surprise category.
Why are vision changes on the warning list?
Clomiphene can cause blurred vision, spots or flashes, and double vision - uncommon, but real enough that MedlinePlus advises against driving until you know how it affects you, especially in poor lighting. Vision symptoms on the drug are a call-the-doctor event, and they usually shape whether future cycles use it at all.
What is the abdominal swelling warning about?
Ovarian hyperstimulation: ovaries that respond too vigorously swell and leak fluid - the pattern is stomach or lower-stomach pain, swelling, rapid weight gain, and shortness of breath. Mild versions are uncomfortable; severe ones are dangerous. That cluster is a call-immediately pattern, and it is the reason some cycles include ultrasound monitoring rather than blind trust.
Why did my doctor rule out other problems before the first cycle?
Clomiphene only fixes one thing - an ovary that does not release eggs. Liver disease, ovarian cysts outside PCOS, fibroids, abnormal bleeding, pituitary tumors, and thyroid or adrenal disease are on the flag list because they either make the drug unsafe or make it pointless. The workup first is what makes the five tablets a strategy instead of a lottery ticket.
What happens if I miss a dose of clomiphene?
Call your prescriber - this is the one drug where the missed-dose advice is not "take it when you remember." The 5-day course is timed to the cycle, and a shifted dose can mistime the whole cycle. Your doctor will tell you whether to continue, adjust, or wait for next month.