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Ospemifene Side Effects

In Summary

More frequently reported side effects include: endometrial hyperplasia and hot flash. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to ospemifene: oral tablet


Oral route (Tablet)

Ospemifene is an estrogen agonist/antagonist that has tissue selective effects and estrogen agonistic effects in the endometrium. Risk of endometrial cancer is increased in women with a uterus who use unopposed estrogens. Risk of endometrial hyperplasia is reduced with the addition of a progestin to estrogen therapy. Therapy with estrogen-alone increases the risk of stroke and DVT. DVT and cerebral thromboembolic and hemorrhagic stroke have been reported with ospemifene use.

Along with its needed effects, ospemifene may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking ospemifene:

More Common

Less Common

  • Anxiety
  • chest pain
  • confusion
  • cough
  • difficulty with speaking
  • dizziness or lightheadedness
  • double vision
  • fainting
  • fast heartbeat
  • headache
  • inability to move the arms, legs, or facial muscles
  • inability to speak
  • pain, redness, or swelling in the arm or leg
  • slow speech
  • sudden shortness of breath or troubled breathing


  • Chest discomfort
  • nausea
  • pain or discomfort in the arms, jaw, back, or neck
  • shortness of breath
  • sweating
  • vomiting

Some side effects of ospemifene may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More Common

  • Feeling of warmth
  • increased sweating
  • redness of the face, neck, arms, and occasionally, upper chest

Less Common

  • Muscle spasms
  • white or brownish vaginal discharge

For Healthcare Professionals

Applies to ospemifene: oral tablet


The more commonly reported adverse events have included hot flush, vaginal discharge, muscle spasms, genital discharge, and hyperhidrosis.


In the clinical trials, the incidence rates of thromboembolic and hemorrhagic stroke in women receiving this drug were 1.13 and 3.39 per thousand women years, compared with 3.15 and 0 per thousand women years in placebo. Two cases of myocardial infarction occurred in women receiving this drug and 2 cases of deep vein thrombosis.

This drug has been reported to initiate or increase the occurrence of hot flashes in some women. In phase 2/3 clinical trials, about 1% of women discontinue this drug due to hot flushes.[Ref]

Common (1% to 10%): Hot flashes

Uncommon (0.1% to 1%): Hemorrhagic stroke, deep vein thrombosis (DVT)

Rare (less than 0.1%): Thromboembolic stroke, myocardial infarction

Postmarketing reports: Thrombosis, pulmonary embolism[Ref]


Postmarketing reports: Pulmonary embolism


Postmarketing reports: Endometrial hyperplasia, endometrial cancer


During clinical trials, one case of simple hyperplasia without atypia occurred. Endometrial thickening of 5 mm or greater was observed in women taking 60 mg/day at a rate of 60.1 per thousand compared to 21.2 per thousand in the placebo group. Any type of proliferative (weakly plus active plus disordered) endometrium was reported at 86.1 per thousand in women taking this drug compared with 13.3 per thousand for placebo. Uterine polyps occurred at an incidence of 5.9 per thousand compared with 1.8 per thousand in those receiving this drug and placebo, respectively. Endometrial cancer was not reported in trials up to 52 weeks long.[Ref]

Common (1% to 10%): Vaginal discharge, genital discharge, proliferative endometrium, endometrial thickening

Uncommon (0.1% to 1%): Uterine polyps

Rare (less than 0.1%): Simple hyperplasia without atypia[Ref]


Common (1% to 10%): Hyperhidrosis

Postmarketing reports: Rash, rash erythematous, rash generalized, pruritus, urticaria[Ref]


Common (1% to 10%): Muscle spasms[Ref]


Postmarketing reports: Allergic conditions including hypersensitivity, angioedema

Nervous system

Postmarketing reports: Headache


1. "Product Information. Osphena (ospemifene)." Shionogi USA Inc, Florham Park, NJ.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.