There are many reasons why women like to wear lipstick. Some believe the right color can enhance their look, while others receive a boost in confidence. However, women who wear lipstick may also want to take an IQ test, as the product on their lips could be lowering their intelligence.

Good Morning America recently commissioned a study of 22 different lipsticks and lip glosses to find out if they contain lead, a toxic metal that can cause serious health problems. The cosmetic products were then taken to Underwriters Laboratories for testing, and it was found that 12 of the samples did contain trace amounts of lead.

While lead is known to be hazardous to people's health, it is not illegal for companies to include the metal in cosmetic products, Roy Lamothe, Underwriters Laboratories' general manager, told the news source.

"What we know now is that even the lowest levels of lead can harm your IQ, your behavior, your ability to learn, so we want to make sure that it is out of everything that is in the environment of children," Sean Palfrey, medical director for the Boston Lead Poisoning Prevention Program, told the news outlet.

Research has shown that exposure to lead in adults can lead to the development of memory and concentration problems, according to The National Institute of Environmental Health Sciences. Among children, exposure to this metal has been linked to changes in their mental development.