What Are the Side Effects of Isoflavones?

Isoflavones are said to have various benefits, but they also come with some side effects that can be bothersome and even dangerous for those who take this substance. Some side effects of isoflavones mostly affect women, because pregnant women and those who have battled breast cancer usually are most at risk of experiencing negative effects. Any woman, however, may be affected by hot flashes and weight gain when taking isoflavones. Men, on the other hand, may notice a reduced libido, infertility and memory loss while taking isoflavone supplements. Other side effects of isoflavones can affect both women and men, with diarrhea, food allergies, and headaches being some of the most common issues.

Some side effects are specific to females, because isoflavones may affect the hormonal balance in the female body, leading to some negative consequences. For example, those who have a history of breast cancer usually are discouraged from taking isoflavones because they can stimulate breast cancer cells that already may be present. Isoflavones also are said to interfere with breast cancer treatment drugs, but women without a history of this type of cancer usually are considered safe from this possible side effect. An additional concern is that isoflavones could be detrimental to unborn babies, who need a specific balance of hormones to develop properly in the womb, so pregnant women usually are advised to skip this type of supplement. Any woman is susceptible to the weight gain and hot flashes that can come with isoflavones, so females are advised to ensure that the possible benefits outweigh the possible side effects.

Men also may experience some side effects of isoflavones that women may not get, because the two usually have different hormonal balances. One of the biggest side effects in men is a reduced libido, because increased estrogen can lead to decreased testosterone levels, which also may result in infertility. Additional side effects for men may include fatigue, memory loss and decreased cognitive function. Many studies show that women do not experience these side effects of isoflavones, so men should keep this in mind before taking this substance based on favorable reviews from women.

Some side effects of isoflavones affect both men and women. Some people become constipated while taking soy isoflavones, while others may have diarrhea and an upset stomach. Headaches and a sensation of dizziness also are some negative effects of isoflavones. It also is possible that this substance causes kidney stones, food allergies and thyroid issues, so people who decide to take isoflavones are advised to keep an eye out for these side effects.