Nearly the entire female population over the age of 13 is familiar with the uncomfortable and borderline unbearable symptoms of PMS. Ladies, all this pain and discomfort may soon be a thing of the past. A team of scientists working on a cure for PMS believe they’ve found the answer in a most unexpected place: the common antidepressant, Prozac.

But while most of us are able to tell when we’re PMSing, few actually know what’s happening on a biological level to cause these unpleasant symptoms. In a nutshell, PMS, or premenstrual syndrome, is a mild form of chemical withdrawal. It’s believed that PMS is caused by a fall in the secretion of the ovarian sex hormone progesterone. According to a press release, this fall occurs near the end of the menstrual cycle and subsequently leads to a decline in a chemical called allopregnanolone. This particular agent acts in the brain as a fairly powerful sedative and tranquilizer, and when the production is suddenly cut off women experience symptoms associated with PMS.

Working off this tangent, a team of researchers have suggested a novel way to prevent this withdrawal from ever occurring, using a fairly common drug. In their study, the researchers found that when mice were exposed to low levels of fluoxetine, the main ingredient found in the antidepressant Prozac, the allopregnanolone withdrawal was avoided. This is because the drug was able to inhibit the enzyme which deactivates allopregnanolone. The result was an unaltered chemical balance of this natural sedative in the brain.

“Our work in rats shows that fluoxetine can prevent PMS-like symptoms at low doses, which have no effect on serotonin reuptake,” Dr. Jonathon Fry, a researcher involved in the study told Medical Daily in an email.

The researchers are most confident that similar results could be replicated in humans. Theoretically, this means that women would not just be able to treat the symptoms associated with PMS, but actually completely avoid them. The drug would may also prove helpful in the prevention of postnatal depression, a condition also prompted by progesterone withdrawal, Fry explained.

“We would hope that our work will lead to a way to prevent symptoms developing. The idea would be that women would start to take medication during the last 7-10 days of their cycle before their period is due,” Dr. Thelma Lovick, a second researcher involved in the study told Medical Daily via email.

Not only did the fluoxetine target the root of PMS symptoms, but also, due to the low amounts of the drug needed to get this result, there were no side effects observed in the lab rats.

Although about 80 percent of women experience PMS, the severity of their symptoms differs greatly. Common symptoms of PMS include: mood swings, tender breasts, food cravings, fatigue, irritability, depression, sleep deprivation, and increased sensitivity to pain.

“We would hope to be able to offer treatment to any woman who finds their symptoms troublesome and who, importantly, would like medication,” explained Lovick, emphasizing that, of course, the drug would only be able to prevent PMS symptoms that were prompted by progesterone withdrawal. Some of the more severe cases of PMS are caused by other factors.

Lovick informed Medical Daily that the team will soon begin human trials in Brazil.

Source: Fry JP, Li KY, Devall AJ, Cockcroft S, Honour JW, Lovick TA. Fluoxetine elevates allopregnanolone in female rat brain but inhibits a steroid microsomal dehydrogenase rather than activating an aldo-keto reductase. British Journal of Pharmacology. 2014