It appears that one man’s poison may be another woman’s stroke treatment, according to new research published in the journal Stroke.

The study found that giving female stroke patients a dose of uric acid, a chemical more often recognized as a waste byproduct in urine, helped them better recover without disability, compared to a control group. They also had better blood flow and, as a result, less dead tissue circulating in their body. Peculiarly enough, there was no such treatment effect seen with men who were given uric acid.

The study authors reexamined 2014 data taken from the URICO-ICTUS study, a randomized, double-blind trial of 411 patients, split equally between genders, who were admitted to stroke centers in Spain. Those enrolled in URICO-ICTUS, after they received treatment to clear away the lodged blood clots that caused their stroke, were either given 1000 mg of uric acid or placebo.

42 percent of women given uric acid recovered from their stroke without disability, compared to 29 percent who had taken a placebo, while there was no improvement seen over either group of men, both around 35 percent.

“While high levels of uric acid can lead to other health problems, uric acid also helps protect tissue from harmful molecules known as free radicals,” said lead author Dr. Ángel Chamorro, director of Barcelona’s Comprehensive Stroke Center, Hospital Clinic Chamorro, in a statement.”Women fare better with uric acid therapy because they tend to have less uric acid in their bodies.”

According to the American Heart Association (AHA), free radicals are released when the clots from a stroke are broken, and oxygen is restored to the brain. Uric acid is known to be a particularly strong antioxidant, but in high enough doses is associated with kidney damage and gout. The AHA also notes that 55,000 more women have a stroke than men annually, and are more likely to die or become disabled as a result of it.

Because the women studied were on average older and had comorbid health conditions like high blood pressure, the researchers believe the protective effects of uric acid therapy could be even more profound in younger more robust stroke sufferers. They also hope to explore the possibility that uric acid can be beneficial to male stroke victims with already low levels of uric acid or in those whose bodies are likely to carry more free radicals because of their high blood sugar or other medical conditions.

Source: Llull L, Laredo C, Renú A, et al. Uric Acid Therapy Improves Clinical Outcome in Women With Acute Ischemic Stroke. Stroke. 2015