Clomid Guide: Ovulation, Use in Men and Safety Facts

Clomid is the brand name for clomiphene citrate, a prescription drug approved by the FDA for "the treatment of ovulatory dysfunction in women desiring pregnancy." It belongs to a class called selective estrogen receptor modulators (SERMs). Instead of adding a hormone, it changes how the brain reads estrogen, which leads the body to release more of the hormones that drive ovulation in women and testosterone and sperm production in men.

In the US, Clomid comes as a 50 mg tablet. The current brand label, revised in August 2023, lists Cosette Pharmaceuticals as distributor. Generic clomiphene citrate 50 mg tablets are made by several companies, and the older brand Serophene is listed as discontinued in FDA records. All versions are prescription only.

Every tablet is a mix of two isomers, enclomiphene and zuclomiphene. The label states that the cis form, zuclomiphene, makes up 30% to 50% and has the longer half-life, remaining detectable for more than a month after a dose. That detail explains several of the drug's side effects and why enclomiphene was later developed on its own.

This site covers the drug in plain language with numbers taken from the FDA label and published studies: how it works, how women and men use it, its side effects, its cost, and the newer drug enclomiphene. Clomid.org does not sell any medicine.

The label describes the standard course as 50 mg a day for 5 days, starting on or about day 5 of the menstrual cycle. If ovulation does not occur, the next course is 100 mg a day for 5 days. The label advises against going beyond 100 mg a day for 5 days, and against more than about six cycles in total.

Ovulation "most often occurs from 5 to 10 days after a course," according to the label, which recommends timing intercourse to the expected ovulation and using tests such as a basal body temperature chart to confirm it. In the label's clinical studies of 7,578 women, about 30% became pregnant.

The drug works best when the problem is irregular or absent ovulation, for example in polycystic ovary syndrome. It does not treat blocked tubes or male factor infertility on its own, which is why fertility specialists check both partners before starting. Details of the mechanism are on our how Clomid works page.

For women with polycystic ovary syndrome (PCOS), letrozole now outperforms Clomid in trials. In the PPCOS II trial of 750 women (New England Journal of Medicine, 2014), the cumulative live birth rate was 27.5% with letrozole and 19.1% with clomiphene. The 2023 international PCOS guideline, endorsed by the American Society for Reproductive Medicine, recommends letrozole as the first-line drug for these women.

For unexplained infertility the picture changes. In the AMIGOS trial of 900 couples (New England Journal of Medicine, 2015), live births were 23.3% with clomiphene and 18.7% with letrozole, a difference that was not statistically significant. The ASRM 2020 guideline strongly recommends clomiphene with intrauterine insemination for this group.

Letrozole is approved only for breast cancer, so its fertility use is off label, while Clomid is the only one of the two approved for ovulation induction. The full comparison is in Clomid vs letrozole.

Men take it off label for low testosterone and low sperm counts. By raising LH and FSH from the pituitary, it lets the testes produce more testosterone and sperm themselves, which is the main difference from testosterone replacement, which suppresses sperm production.

The research base is large. A 2022 meta-analysis in Andrology covering 19 studies and 1,642 men found total testosterone rose about 2.6-fold, with side effects in under 10% of study populations. A 2019 study of 400 men found 88% reached normal testosterone. A 2023 meta-analysis on male infertility found sperm concentration rose by 8.38 million per mL, with a pregnancy rate of 17% across 10 studies.

It only helps men whose testes can respond, usually those with low testosterone and low or normal LH. Our Clomid for men page explains who responds, typical doses and what to test. Men recovering after anabolic steroid use should read the PCT guide, where the evidence is weaker.

Most side effects are mild. In label data from 8,029 women, the most common were ovarian enlargement (13.6%), hot flushes (10.4%), abdominal or pelvic discomfort and bloating (5.5%), nausea and vomiting (2.2%) and breast discomfort (2.1%).

Three risks deserve more attention:

In men, studies report mood changes, blurred vision, breast tenderness, lower libido and rising estradiol. The full list, including who should not take Clomid, is on our Clomid side effects page.

Enclomiphene is the trans-isomer of clomiphene, separated out and developed as a drug for men. It has a half-life of about 10.5 hours against about 30 days for zuclomiphene. In phase III trials it roughly doubled testosterone from low levels while preserving sperm counts, but it is not FDA approved; the FDA asked for new trials in 2015 and the European Medicines Agency refused it in 2018. What is sold in the US is compounded on prescription. See what enclomiphene is.

Generic clomiphene is inexpensive. On 30 September 2026, GoodRx listed it from $17.31 with a coupon, against an average retail price of $56.67. Insurance coverage depends on the state and the plan. The Clomid cost guide covers prices, coupons and coverage, and our products page explains the tablets and generics available.

Clomid.org is an independent educational resource. We are not affiliated with any pharmaceutical manufacturer, compounding pharmacy, telehealth company or healthcare provider. This content is for informational purposes only and does not constitute medical advice. Images on this site are illustrative artwork made for editorial purposes; they do not show real products, packaging or labels and are not an advertisement or an offer to sell.