What are the side effects of Clomid (clomiphene citrate)?

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Last updated: April 17, 2025View editorial policy

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From the Guidelines

Clomid (clomiphene citrate) is associated with several side effects, including hot flashes, mood swings, headaches, breast tenderness, nausea, and abdominal bloating, as a result of its mechanism of action which involves blocking estrogen receptors in the brain to stimulate ovulation. When considering the management of polycystic ovary syndrome (PCOS) and the use of clomiphene citrate for ovulation induction, as discussed in the guidelines released by the American College of Obstetricians and Gynecologists (ACOG) in 2003 1, it is crucial to weigh the benefits against the potential side effects. The ACOG guidelines recommend clomiphene citrate due to its effectiveness, with about 80 percent of women with PCOS ovulating and one half of these patients conceiving 1. However, the side effects of clomiphene citrate can be significant and include:

  • Hot flashes
  • Mood swings
  • Headaches
  • Breast tenderness
  • Nausea
  • Abdominal bloating
  • Visual disturbances such as blurred vision or seeing spots
  • Ovarian enlargement, which can cause pelvic pain or discomfort
  • Multiple pregnancies (twins or more) due to increased ovulation
  • Vaginal dryness or changes in cervical mucus
  • More serious but less common side effects like ovarian hyperstimulation syndrome (OHSS), which causes severe abdominal pain, bloating, and nausea
  • Allergic reactions, though rare, can occur with symptoms like rash, itching, or swelling. It is essential for patients to report severe symptoms to their healthcare provider immediately, as most side effects are temporary and resolve after stopping the medication. In the context of real-life clinical medicine, the decision to use clomiphene citrate should be made with caution, considering the potential side effects and the individual patient's risk factors and medical history.

From the FDA Drug Label

OVERDOSAGE Signs and Symptoms Toxic effects accompanying acute overdosage of clomiphene citrate have not been reported. Signs and symptoms of overdosage as a result of the use of more than the recommended dose during clomiphene citrate therapy include nausea, vomiting, vasomotor flushes, visual blurring, spots or flashes, scotomata, ovarian enlargement with pelvic or abdominal pain. The side effects of clomid (clomiphene citrate) include:

  • Nausea
  • Vomiting
  • Vasomotor flushes
  • Visual blurring
  • Spots or flashes
  • Scotomata
  • Ovarian enlargement with pelvic or abdominal pain 2

From the Research

Side Effects of Clomid

  • Ovarian hyperstimulation syndrome (OHSS) is a recognized complication of ovulation induction with clomiphene citrate, although it is rare 3, 4
  • Psychotic reactions, including formal and rational thought disturbances, perceptory and sensory delusions, have been reported in patients undergoing ovarian stimulation with clomiphene citrate 5
  • Common side effects of clomiphene citrate include hot flushing, enlargement of the ovaries, and central nervous symptoms such as nervousness, sleeplessness, headaches, visual disturbances, and vertigo 5
  • The use of clomiphene citrate or letrozole with or without gonadotropins may be associated with a significant increase in the incidence of cycle cancellations, as well as reductions in the mean number of oocytes retrieved 6
  • Clomiphene citrate or letrozole protocols were associated with a reduction in the incidence of OHSS 6

Specific Studies

  • A case report of severe OHSS induced by clomiphene citrate highlighted the importance of full assessment and risk prediction before prescribing clomiphene citrate 3
  • A study on the use of clomiphene citrate or aromatase inhibitors with gonadotropins for controlled ovarian stimulation in women undergoing in vitro fertilization found that these protocols were associated with a reduction in the incidence of OHSS, but may be associated with an increase in cycle cancellation rate 6
  • A Cochrane review on gonadotropins for ovulation induction in women with polycystic ovary syndrome found that gonadotropins probably result in more live births and clinical pregnancies than continued clomiphene citrate, but may increase the miscarriage rate per woman 7

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Severe ovarian hyperstimulation syndrome induced by clomiphene: a case report.

Gynecological endocrinology : the official journal of the International Society of Gynecological Endocrinology, 2022

Research

Gonadotropins for ovulation induction in women with polycystic ovary syndrome.

The Cochrane database of systematic reviews, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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