Candace Jones suffered monthly menstrual pains throughout adolescence, but she didn't fully understand how bad they were until she went into labor with her first child.
"The cramping was so severe you could compare it to the contractions with the baby," said the 26-year-old Springfield, Va., mother.
Since having two children and turning to a new form of birth control -- the IUD -- the cramps have subsided, she said, but the memories of missing running and swimming practices and staying in bed with a heating pad are still vivid.
Jones, like about 15 percent of all menstruating women, suffered from dysmenorrhea -- stabbing or aching lower abdominal or back pain that can cripple women for days each month.
For generations, the only treatment for menstrual pain was over-the-counter medicines like Motrin and Midol. But now, there may be a cure for the root cause of the cramping.
Scientists have created a pill that targets the cause of stomach cramps, rather than just treating its symptoms. The drug, known as VA111913, has been manufactured by the British company Vantia Therapeutics and is in clinical trials in Britain and in the United States.
So far, it has been proven safe and has few side effects and could be on the market in four years if secondary trials are successful.
'I think it would be fair to call it a breakthrough. There is certainly no other treatment like it," Vantia researcher Dr. Jim Phillips told Britain's Daily Mail. "From our research there is nothing to suggest it won't work."
During the next two months in the United States, the National Institutes of Health (NIH) will test the drug on 128 women between ages 18 and 35 who describe their menstrual pain as severe enough to interfere with daily life. They will receive VA111913 for a maximum of six days during their menstrual cycle.
The drug would be used to treat primary dysmenorrhea, which is defined as pain that occurs in otherwise healthy women.
Causes of secondary dysmenorrhea can be fibroids, endometriosis, ovarian cysts, pelvic inflammatory disease and infections from sexually transmitted diseases, according to Medline Plus, an online resource for the NIH.
The new drug works as a receptor on the hormone vasopressin, which has effects on fluid balance and smooth muscles like the heart and the uterus, according to Dr. Michelle Warren, medical director of the Center for Menopause, Hormonal Disorders and Women's Health at Columbia University.
"About 15 percent of all women have cramps bad enough to keep them at home on strong pain medicine, especially in their early years under 20," Warren told ABCNews.com.
"If it last a day or more, it's considered severe," she said.
The "old standbys" like anti-inflammatory drugs are somewhat effective, according to Warren. "But getting cramps is annoying and worrisome on the day you are getting married or your senior prom."
"The pain is real," she said. "That's why they call it the curse."
Sometimes women resort to stronger painkillers that can zone them out and have numerous side effects.
Tina, a 29-year-old administrative assistant from New York City who did not want her last name used, said she suffers so severely from cramping that her mother sends her codeine-based pain medication from Britain, where it can be purchased over the counter.