September 19, 2021

Tamoxifen Side Effects

Many forms of breast cancer require the presence of estrogen to grow. Drugs like tamoxifen make it difficult for estrogen to bind with receptors in the body. By doing this, tamoxifen reduces the growth of breast cancer cells and prevents a relapse. This medication was originally sold by Imperial Chemical Industries. Since its patent expired, it has been created and sold by other companies in the market.

Studies of tamoxifen show that it decreases the risk of breast cancer in middle-aged and older women. At the same time, tamoxifen increases the chances of adverse side effects. One positive aspect of tamoxifen is that it can prevent women from losing bone density. Patients who take tamoxifen have a lower incidence of bone related diseases like osteoporosis. When this medication first hit the market, experts had been afraid that tamoxifen would contribute to the loss of bone density. Scientists hypothesized that it would block estrogen receptors in the bone as well as the breast. After clinical trials, researchers now know that tamoxifen actually prevents losses to bone density.

Side Effects of Tamoxifen

In certain cases, tamoxifen has been linked to a rise in endometrial cancer and uterine cancer. The risk of cancer is heightened if patients take tamoxifen for periods longer than five years. Some women have reported decreased mental acuity and alertness as well as memory issues. In addition, tamoxifen can cause an increase in triglycerides, fatty liver, thromboembolism and loss of sexual libido.

Overall, patients who take tamoxifen might experience:

  • tamoxifen side effectsHeadaches
  • Nausea
  • Vomiting
  • Rashes
  • Loss of sexual libido
  • Increase in stroke
  • Cataracts or vision problems
  • Endometrial cancer
  • Uterine cancer
  • Loss of bone density in premenopausal women
  • Constipation
  • Vaginal discharge
  • Hot flashes
  • Coughing
  • Fatigue
  • Weight loss

In some cases, patients may suffer from a severe allergic reaction. They could develop hives, breathing problems, swelling or tightness in the chest. Anyone who experiences these symptoms should see their doctor as soon as possible. On rare occasions, tamoxifen can cause severe side effects. Anyone who experiences a severe side effect should immediately discuss alternative treatments with their physician.

Some of these side effects include:

  • Abnormal menstrual periods
  • Chest pain
  • Groin pain
  • Swelling in legs
  • Jaundice
  • Breast pain or lumps
  • Dark urine
  • Unusual vaginal bleeding or discharge
  • Vision or speech difficulties

If you or a loved one experiences any of these symptoms, you should immediately consult a qualified medical practitioner. In some cases, the side effects of tamoxifen can mimic menopause. If these symptoms are an issue, your doctor can discuss ways to manage the side effects.


Tamoxifen should not be taken by a woman who is pregnant, nursing or may become pregnant. The FDA lists tamoxifen as a pregnancy category D drug. This classification means that the FDA considers tamoxifen to be a threat to the fetus or infant. Women who plan on becoming pregnant should wait at least two months after they stop taking tamoxifen. Patients who have a history of heart, liver, lung or kidney problems should always tell their doctor before taking this drug.

While taking tamoxifen, doctors will often do routine checks and laboratory tests on the patient. This is to ensure that tamoxifen does not have a negative impact on the body. Although this drug carries with it several severe side effects, patients must weigh the potential benefits provided by the medication. Women who have recently had breast cancer experience longer survival rates and a lower incidence of relapse.

The only person who can decide if tamoxifen is right for you is your doctor. Before taking tamoxifen, you should tell your doctor about any medications, allergies or medical problems. If you ever experience side effects while taking tamoxifen, make an appointment with your doctor or receive emergency medical care services immediately.