Key takeaways:
Clomid (clomiphene) works by helping your body ovulate.
Signs that Clomid is causing ovulation can be subtle. They include things like a small rise in your early-morning temperature (basal body temperature), breast tenderness, and clear, slippery cervical mucus.
Clomid works quickly. Ovulation usually happens 5 to 10 days after starting it. But it can take more than one cycle to get pregnant while taking Clomid.
Trying to get pregnant can be a nerve-wracking process, especially if you’re having trouble getting pregnant. Fertility medications can increase your chances of getting pregnant. But how can you tell if they’re working?
Clomid is one of the most commonly prescribed fertility medications. Here’s how you can tell if Clomid is working.
How does Clomid work?
Clomiphene (Clomid) is a fertility medication taken by mouth. It belongs to a class of medications called selective estrogen receptor modulators (SERMs).
Search and compare options
Clomid works by attaching to estrogen receptors in your body. This “tricks” your brain into thinking estrogen levels are low. In response, your brain releases more of two hormones: luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These hormones help your ovaries mature and release an egg.
In other words, Clomid helps your body ovulate in a regular and predictable way. This increases the chances of getting pregnant for women with certain conditions that affect fertility, like polycystic ovary syndrome (PCOS).
Clomid can also be prescribed off-label to treat male infertility. Some research suggests that Clomid can increase testosterone levels and improve sperm production for some men. But these hormone and semen changes haven’t consistently led to higher pregnancy rates.
In other words, lab values may improve, but that doesn’t always mean the chances of getting pregnant also improve. This is an important difference from how Clomid works in women, where its effects are clearly linked to improved pregnancy rates.
5 signs Clomid is working
Clomid’s main job is to help your body ovulate. If it’s working, you’ll likely notice signs that ovulation is happening. Here’s what that can look like.
Increased basal body temperature
Your basal body temperature (BBT) is your body’s temperature first thing in the morning, before you get out of bed or move around. Your BBT will increase the morning after you ovulate.
If Clomid is working and you ovulate, you’ll typically see your temperature rise by at least 0.4°F the morning after ovulation and stay elevated for about 3 days.
To track this at home, use a digital basal thermometer. Take your temperature every morning at the same time, before sitting up, eating, or drinking. Record the reading each day so you can look for patterns over time.
Cervical mucous changes
Cervical mucus is fluid made by your cervix. You may notice it on your underwear or when you wipe. The amount and texture change throughout your menstrual cycle in response to hormone levels.
As ovulation gets closer, cervical mucus usually becomes wetter, clearer, and more slippery. Right before, during, and just after ovulation, it’s more stretchy, smooth, and elastic.
Not everyone notices these changes. Some people don’t make a lot of mucus and certain medications, stress, or dehydration can affect how much you see.
Breast changes
Hormone changes during your menstrual cycle can affect breast size, fullness, and sensitivity.
After ovulation, progesterone levels rise. This can cause milk glands (lobules) in your breasts to swell slightly. You may notice that your breasts feel fuller, tender, or more sensitive for several days following ovulation.
Not everyone notices breast changes. But if you usually don’t have breast tenderness and begin noticing it after starting Clomid, it may be a sign you’re ovulating.
Pregnancy
The ultimate goal of Clomid therapy is a healthy pregnancy. Seeing a positive pregnancy test can be an exciting — and emotional — sign that the medication did its job.
Studies show Clomid successfully triggers ovulation in about 60% to 80% of women. Among women with PCOS who successfully ovulate while taking Clomid, about 3 out of 4 become pregnant within 6 to 9 months.
If pregnancy doesn’t happen right away, that doesn’t mean Clomid isn’t working. Many people need several cycles before getting pregnant. Your healthcare team can help you decide what steps to take next based on how your body responds.
How long does it take Clomid to start working?
Clomid starts working quickly. That’s why your healthcare team will give you specific instructions on how to start taking it. Usually, you start taking Clomid on the 5th day of your menstrual cycle.
You may notice signs of ovulation as early as 5 to 10 days after starting Clomid. But it can take a few menstrual cycles to get pregnant, even if Clomid starts working right away.
What are the side effects of Clomid?
Like all medications, Clomid can cause side effects. Most of them are mild. The most common Clomid side effects include:
Hot flashes
Nausea and vomiting
Changes in mood
Difficulty sleeping
Abdominal bloating
Most people only take Clomid for a few days at a time. Side effects tend to go away quickly after you stop taking it. But they may come back when you restart the medication during your next menstrual cycle.
What symptoms should you watch for when taking Clomid?
Serious side effects from Clomid are rare. But there are two important side effects to be aware of if you’re taking Clomid:
Ovarian hyperstimulation syndrome (OHSS): OHSS happens when your ovaries overreact to fertility medications and become swollen and painful. Mild cases can cause bloating, pain, and rapid weight gain from fluid buildup. In more severe cases, symptoms may include significant abdominal pain, nausea, vomiting, shortness of breath, or blood clots. Clomid rarely causes OHSS by itself. But your risk may be higher if you take Clomid with other injectable fertility medications.
Vision changes: Vision problems are another rare but potentially serious side effect of Clomid. Some people report blurred vision, sensitivity to light, flashes, or seeing spots. If you notice any changes in your vision while taking Clomid, contact your healthcare team right away.
The bottom line
If you’re taking Clomid, the biggest sign it’s working is that you’re ovulating — even if pregnancy doesn’t happen right away. Signs of ovulation include breast tenderness, cervical mucus changes, and increases in your basal body temperature. Many people need more than one cycle to get pregnant, even when Clomid works right away to trigger ovulation.
Why trust our experts?
References
American College of Obstetricians and Gynecologists’ Committee on Practice Bulletins—Gynecology. (2018). ACOG practice bulletin no. 194: Polycystic ovary syndrome. Obstetrics and Gynecology.
Mbi Feh M. K., et al. (2024). Clomiphene. StatPearls.
MedlinePlus. (2023). Follicle-stimulating hormone (FSH) level tests.
MedlinePlus. (2023). Luteinizing hormone (LH) level tests.
MedlinePlus. (2024). Premenstrual breast changes.
MedlinePlus. (2025). Ovarian hyperstimulation syndrome.
Practice Committee of the American Society for Reproductive Medicine. (2006). Use of clomiphene citrate in women. Fertility and Sterility.
Racette, L., et al. (2010). An investigation of the visual disturbances experienced by patients on clomiphene citrate. Fertility and Sterility.
Sanofi-Adventis. (2012). CLOMID (clomiphene citrate tablets USP) [package insert].
Santi, D., et al. (2025). Empirical hormonal treatments for idiopathic male infertility: A network meta-analysis comparing antiestrogens and FSH. European Journal of Endocrinology.
Smoley, B. A., et al. (2012). Natural family planning. American Family Physician.
Steward, K., et al. (2023). Physiology, ovulation and basal body temperature. StatPearls.
UNC School of Medicine. (n.d.). Cervical mucus monitoring.
Usadi, R. S., et al. (2008). Induction of ovulation with clomiphene citrate. Global Library of Women’s Medicine.
Vandekerckhove, P., et al. (2000). Clomiphene or tamoxifen for idiopathic oligo/asthenospermia. The Cochrane Database of Systematic Reviews.
