What Is Clomid? Clomiphene Citrate Explained: Uses, Dose, Risks

What is Clomid? It is the brand name of clomiphene citrate, an oral tablet that makes the body release more of its own follicle-stimulating and luteinizing hormone. Its FDA-approved use is one: treating ovulatory dysfunction in women who want to become pregnant. It comes as a 50 mg tablet, is taken for five days per cycle, and was approved by the FDA in 1967, which makes it the oldest fertility drug still in standard use. Off-label, it is one of the most common prescriptions for men with low testosterone who want to keep their fertility, because unlike testosterone injections it raises the hormone without shutting the testes down.

The generic name is clomiphene citrate; outside the United States the international name is clomifene, and both spellings refer to the same molecule. Clomid is the original brand, now sold in the US by Cosette Pharmaceuticals; Serophene was a second brand name for the same drug. Generic clomiphene citrate tablets are made by a small number of manufacturers, which is why the drug goes in and out of stock at pharmacies more often than most generics.

Every tablet is 50 mg, so "clomid 50mg" and "Clomid" mean the same product; dosing differences come from how many tablets are taken and on how many days. The drug is a mixture of two isomers, enclomiphene and zuclomiphene; the label specifies between 30% and 50% zuclomiphene, the rest enclomiphene. Enclomiphene is the active estrogen blocker and clears in days; zuclomiphene is weakly estrogenic and, according to the label, can be detected for more than a month. The isomer difference is the basis for enclomiphene as a separate product, covered in enclomiphene vs Clomid.

Estrogen normally tells the hypothalamus that the reproductive system is doing enough, and the hypothalamus answers by slowing its pulses of GnRH. Clomiphene sits on those estrogen receptors without activating them, so the hypothalamus reads estrogen as low, GnRH pulses speed up, and the pituitary releases more FSH and LH. The rest depends on who is taking it.

In a woman who is not ovulating, the extra FSH recruits a follicle and grows it; a surge of LH then releases the egg. The label says ovulation most often occurs 5 to 10 days after the last of the five tablets. In a man, the extra LH drives the Leydig cells of the testes to make testosterone, and the extra FSH supports sperm production. In both cases the drug only works if the pituitary and gonads can respond: it removes a brake, it does not supply fuel. The mechanism in more depth is on how Clomid works.

Approved use: women with ovulatory dysfunction, after other causes of infertility have been excluded or treated, with a normal liver and no ovarian cysts other than those of polycystic ovary syndrome. About 8 in 10 suitable women ovulate on it, and pregnancy occurred in about 30% of the 7,578 women in the label's trials. The full protocol and success data are in Clomid for women.

Off-label use in men: low testosterone from a secondary cause, where the testes work but are under-stimulated. A 2022 meta-analysis of 19 studies and 1,642 men found a consistent rise in testosterone with side effects in fewer than 10%, and the 2018 American Urological Association guideline lists SERMs as an option for men who want to preserve fertility. Typical study doses were 25 mg daily or 25 to 50 mg every other day, far below the women's label dose. Details are in Clomid for low testosterone.

Off-label use after anabolic steroids: restarting natural testosterone production once a cycle ends, the use covered in the Clomid PCT guide.

Off-label use in male infertility: raising FSH to improve sperm counts, where the evidence is weaker and mixed.

For women, the label is explicit: 50 mg once a day for five consecutive days, starting on or about the fifth day of the cycle; intercourse timed to the expected ovulation 5 to 10 days after the last tablet; a second course at 100 mg if the first did not produce ovulation; no more than 100 mg a day, no more than three courses without ovulation, and no more than about six cycles in total. A pelvic examination is required before every course.

For men there is no label dose, because the use is off-label. The studies used 25 mg daily, 25 mg every other day or 50 mg every other day, with blood work at four weeks to decide whether to stay or step up. Doses above 50 mg daily add estradiol and side effects without adding much testosterone.

From the label's 8,029 women: ovarian enlargement 13.6%, hot flashes 10.4%, bloating or pelvic discomfort 5.5%, nausea 2.2%, breast discomfort 2.1%, visual symptoms 1.5%, headache and abnormal bleeding 1.3% each. Visual symptoms are the reason to stop the drug and see an eye doctor, because the label states they can be prolonged or irreversible with higher doses or longer use. Ovarian hyperstimulation syndrome is rare on Clomid but carries its own warning. Twins occurred in 6.9% of the label's pregnancies.

In men, side effects in the studies ran below 10%, mainly hot flashes, headache, mood changes and breast tenderness, with estradiol rising alongside testosterone. The two profiles are covered in Clomid side effects in women and Clomid side effects in men.

Neither. Clomiphene is a non-steroidal compound of the same chemical family as tamoxifen, and it contains no estrogen, testosterone or progesterone. It is grouped with anabolic steroids in discussions only because steroid users take it afterwards to restart their own testosterone. It is not banned for ordinary patients, but it is a prohibited substance in competitive sport under the World Anti-Doping Agency list, in the class of hormone and metabolic modulators, because of its effect on testosterone.

For women with PCOS, letrozole has overtaken Clomid as the first choice at many clinics since a 750-woman trial in 2014 found more live births on letrozole (27.5% versus 19.1%) and fewer twins; the comparison is in Clomid vs letrozole. For other causes of anovulation, and in countries where letrozole is not licensed for fertility, Clomid remains standard. For men, enclomiphene, the active isomer alone, is increasingly prescribed in its place because it leaves out the long-lasting zuclomiphene, though it is not FDA-approved either. And on price, generic clomiphene remains one of the cheaper fertility drugs per cycle, covered in Clomid cost.

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