Side Effects of Progesterone Capsules

Common Side Effects of Progesterone Capsules

Progesterone capsules have been studied thoroughly in clinical trials. In these studies, the side effects that occurred in a group of women taking the drug were documented and then compared to the side effects that occurred in another group taking a placebo (a "sugar pill" that does not contain any active ingredients). As a result, it was possible to see what side effects occurred, how often they appeared, and how they compared to the group not taking the medicine.
In studies of progesterone capsules for treating the absence of menstrual periods before menopause (amenorrhea), the most common side effects included:
  • Dizziness -- in up to 24 percent of women
  • Abdominal (stomach) pain or cramping -- up to 20 percent
  • Headaches -- up to 16 percent
  • Breast pain -- up to 16 percent
  • Muscle or bone aches and pains -- up to 12 percent
  • Viral infections -- up to 12 percent.
Progesterone capsules have also been studied for use in combination with estrogen medications as hormone replacement in postmenopausal women. It is important to note that some of the side effects could be due to the estrogen used in the study, not necessarily to progesterone capsules. Common side effects of progesterone capsules for postmenopausal hormone replacement therapy (in combination with an estrogen) included:
  • Headaches -- in up to 31 percent of women
  • Breast tenderness -- up to 27 percent
  • Depression -- up to 29 percent
  • Dizziness -- up to 15 percent
  • Abdominal bloating -- up to 12 percent
  • Vaginal discharge -- up to 10 percent.
Other common side effects (occurring in 1 to 9 percent of women) for either use included:
Last reviewed by: Kristi Monson, PharmD
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