Clomid for PCOS

By CNY Fertility Published on
Clomid for PCOS

Ibruprofen is to a headache as Clomid (Clomiphene) is to someone with PCOS trying to get pregnant.  Clomid is the most common fertility medication and many doctors, including OBGYNs and some Reproductive Endocrinologists, prescribe Clomid widely to induce ovulation and improve the odds of conception in women with and without PCOS. 

Interestingly, another medication named Letrozole has taken over as the preferred first-line medication for treating PCOS-related infertility for most fertility specialists.  

Nevertheless, just because Clomid has been pushed aside the past few years doesn’t mean that Clomid has completely fallen out of favor or been shown ineffective. In fact, it’s quite the opposite; Clomid is incredibly effective in helping those with PCOS get pregnant.

In this article, we will cover everything you need to know about Clomid and PCOS, including how it works, success rates, common Clomid dosages for PCOS, potential side effects, and other helpful tips and possible treatment alternatives to Clomid for PCOS.

What is PCOS

Polycystic Ovary Syndrome (PCOS) is a metabolic and hormonal disorder that commonly causes irregular, infrequent, or non-existent ovulation and menstrual cycles.  PCOS is the most common endocrine disorder for reproductive-aged women and impacts 5-10% of all premenopausal women and is the most common cause of infertility.

Approximately 90–95% of anovulatory women (women to don’t ovulate) seeking treatment for infertility have PCOS.

Anovulatory Women Seeking Infertility Treatment

There is no single test used to diagnose PCOS, but is usually clinically diagnosed by a healthcare provider if you have two or more of the following symptoms:

  • High levels of androgen (male hormones) as shown via blood testing or possibly through symptoms like male-pattern balding, extra hair growth on the face, chin, or body, or acne.
  • Irregular periods
  • Cysts on the ovaries as shown via ultrasound exam

There are however a few other methodologies for diagnosing PCOS and other potential symptoms.

What is Clomid

Clomid (also known by its generic name Clomiphene) is an estrogen receptor modulator. This means that it blocks estrogen receptors which tricks the brain into thinking estrogen levels are low.  This faulty interpretation by the brain then causes the pituitary gland to increase follicle-stimulating hormone (FSH) and luteinizing hormone (LH) secretions.

Clomid is administered in pill form and is the most commonly prescribed and used fertility drug.  

Clomid is also used to treat some forms of male infertility

How Does Clomid Work for PCOS

Clomid works for PCOS by making the body think its estrogen levels are lower than they are; in response, the body secretes more FSH and LH.  FSH and LH are the hormones responsible for stimulating egg development and ovulation.

Thus, by increasing these hormone levels, Clomid stimulates egg production and induces ovulation for women with PCOS experiencing irregular ovulation patterns or those who do not ovulate at all (anovulation.) 

Research has shown that Clomid can significantly improve the chances of clinical pregnancy for women with PCOS.

In fact, studies have shown that when treated with Clomid women with PCOS experience cumulative pregnancy rates close to that of women without PCOS.

Clomid treatment is commonly called ovulation induction and is used in conjunction with fertility treatments like timed intercourse and Intrauterine Insemination (IUI) to increase the chances of success for women with PCOS.

Clomid Success Rate at Inducing Ovulation for those with PCOS 

As mentioned, Clomid is extremely effective at stimulating ovulation, and in some trials, it has caused ovulation in over 80% of participants.

In most studies, the efficacy of Clomid is compared directly to Letrozole.  In one study published by the highly respected New England Journal of Medicine, researchers did just that.  750 women with PCOS were split into two groups, a Clomid treatment group (376 women) and a Letrozole treatment group (376 women.)  In the study, 48.3% of the Clomiphene treatment group ovulated.  61.7% of the Letrozole group ovulated.   

Ovulation Rates of Clomid for those with PCOS

PCOS and Live Birth Success Rates

Of course, most people with PCOS taking Clomid have one ultimate goal in mind, having a live birth.

In the same New England Journal of Medicine study mentioned in the previous section about ovulation rates, 72 of the 376 women treated with Clomid (Clomiphene) had a live birth (19.1%.)  For comparison, 103 of the 374 women treated with Clomid achieved a live birth (27.5%.) 

Live Birth Rates of Clomid for those with PCOS

Both treatments positively affect ovulation and live birth rates, but Clomid faired slightly worse.

Clomid and Intercourse vs. Clomid and IUI Success Rates

Clomid is commonly prescribed with one of two “insemination methods:”

  • Timed intercourse: simply intercourse that is scheduled to take place optimally around the time of ovulation.
  • Intrauterine Insemination (abbreviated as IUI and commonly known as artificial insemination): a process of cleaning, concentrating, and loading sperm into a catheter that can then be used to deposit in the uterus so they have a higher chance of reaching the fallopian tubes, the site of fertilization.

While many choose to switch to IUI treatment after trying multiple failed timed intercourse cycles, some use IUI is used as a first-line treatment alongside Clomid.

Not surprisingly, IUI with Clomid has been shown to increase the chances of achieving pregnancy for women with PCOS compared to timed intercourse and Clomid.

Pregnancy Rates IUI vs Timed Intercourse in those with PCOS

While experts agree IUI is more effective than timed intercourse, not all studies show such dramatic differences.

Clomid for PCOS Dosages

Clomid is usually prescribed at lower dosages for PCOS patients to reduce the chance of ovarian hyperstimulation (exaggerated response to excess hormones) occurring.  Clomid comes in a 50mg pill.  

To start, Clomid is usually prescribed at a 50mg or 100 mg dose for five days, beginning on day 3 or 5 of a woman’s cycle.  If ovulation occurs but no pregnancy results, the starting Clomid regiment is usually replicated for the next cycle. However, if ovulation does not occur during the first cycle, the dose may be increased by increments of 50 mg.  

Please note that the Clomid for PCOS dosage varies from patient to patient.  Be sure to consult with your doctor to determine appropriate dosing for you.

Clomid Side Effects

Clomid is usually relatively well tolerated by most women, but it can produce some minor and other severe side effects, including:

  • headache
  • dizziness
  • nausea
  • vomiting
  • ovary enlargement
  • blurred vision
  • abnormal uterine bleeding
  • pelvic pain
  • Negative effect on the endometrium (cervical music and endometrial morphology)

Serious reactions can also result from Clomid use like ovarian hyperstimulation, multiple pregnancies, risk of ovarian cancer (from prolonged use), and severe visual disturbance.

Clomid Resistance

It is worth noting that many women are resistant to Clomid, meaning they will not ovulate from Clomid treatment.  In fact, the prevalence of clomiphene resistance is as high as 15–40%.   Research has shown that women with a body mass index (BMI) over 25, hyperandrogenism, or poor ovarian reserve (as measured by antral follicle count (AFC), Anti-Müllerian hormone (AMH) and ovarian volume) may be potential indicators for Clomid resistance.   As such, be sure to consult with your doctor to see if Clomid is an appropriate treatment for you.  

Other Medication Alternatives and Supplements for PCOS


As mentioned at the beginning of the article, most fertility specialists have shifted to prescribing Letrozole for PCOS.  Letrozole works similarly to Clomid, though rather than blocking estrogen receptors making it seem like there are lower levels of estrogen, it actually lowers estrogen production; again this increases FSH and LH production.  Letrozole inhibits estrogen production by repressing the enzyme aromatase.  

Research shows that Letrozole produces higher live birth rates and higher ovulation rates when compared to Clomid.   But fertility specialists haven’t only started prescribing Letrozole as a first-line treatment for PCOS due to success rates.  

Letrozole and Clomid Resistance

In the case of Clomid resistance, research has shown that Letrozole can improve ovulation rates and live birth rates for women who have failed to ovulate with Clomid.

Lessened Side Effects

When compared to Letrozole, Clomid has been shown to produce fewer side effects that negatively impact fertility.  Clomiphene can cause a thinner endometrial lining, a higher instance of multiple follicle development, and more multiple pregnancies when compared to Letrozole.


Research has shown that different vitamins and supplements can help to correct hormonal imbalances, restore ovulation and improve female fertility for women with PCOS.

Inositol Supplementation

Insulin resistance is extremely common amongst women with PCOS, affecting approximately 70% of those with PCOS.   Insulin resistance affects fertility by causing the body to produce more androgen hormones affecting the ratio of LH and FSH which impairs egg development and ovulation.   

Inositol for PCOS has been shown to improve blood glucose levels, insulin sensitivity, reduce insulin resistance, increase the chance of ovulation and natural pregnancy and increase fertilization rates of those with PCOS undergoing IVF.

In one of the studies mentioned above, over a 6 month period on inositol, 72% of the women in the study regained normal menstrual and ovulatory activity, and 40% developed singleton pregnancies. 

Ovulation and Pregnancy Rates with Inositol Supplementation 

Fish Oil

Fish oil is a great supplement for PCOS patients because it can improve ovulation, insulin resistance, and has anti-inflammatory properties.   Inflammation is a key contributor to PCOS symptoms.   

Vitamin D

Low vitamin D levels may intensify PCOS symptoms, and 67 to 85% of women with PCOS have vitamin D deficiency.   In addition to improving PCOS symptoms, vitamin D has also been shown to impact pregnancy rates for women undergoing fertility treatments positively.

Other Supplements

In addition to these three critical nutrients, many other nutrients including NAC, Magnesium, COQ10, and More supplements show promise for those with PCOS.

The Bottom Line about Clomid and PCOS

While more and more fertility specialists are ditching Clomid in favor of Letrozole as the go-to medication in helping those with PCOS get pregnant, the fact remains that Clomid is still a highly effective medicine. So the answer to does Clomid work for PCOS is yes and it is still widely and successfully used for PCOS at the OBGYN level and even by some fertility clinics. 

So, if you have PCOS and are looking to get pregnant with the help of Clomid, you’re likely on the right track.  As demonstrated in this article, Clomid has been shown to improve those with PCOS’ chances of getting pregnant greatly. 

But as there is likely a better medication out there for you, we encourage you to explore our full Clomid vs Letrozole article and discuss Letrozole treatment with your healthcare provider.


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