Drug Blocking Interleukin-11 Reduced Ovarian Stiffness and Raised Conception Rates in Older Mice and Rats

An experimental drug that blocks interleukin-11 production reduced ovarian stiffness and increased conception rates in older mice and rats, @NewScientist reported. Researchers at Huazhong University of Science and Technology injected the drug into the tails of 36-week-old mice twice a week for four weeks. The treatment made the ovaries 36 percent less stiff than those of untreated controls.

Treated mice achieved a 50 percent conception rate compared with 25 percent in controls and produced an average of five pups per litter versus three. In similarly aged rats the conception rate rose from 20 percent to 50 percent while average litter size increased from one pup to five.

Mice genetically modified to lack response to interleukin-11 also showed reduced ovarian stiffness with age and ovulated more than unmodified controls.

The team measured interleukin-11 protein levels in ovaries removed from women aged 18-28, 35-42, and 47-52 who had histories of gynaecological cancer but whose ovaries were unaffected. Levels of the protein rose with age. Interleukin-11 activates fibroblasts that produce collagen, a driver of ovarian stiffness.

Mice and rats given the drug experienced no known side effects. The study was published in Nature Aging with the DOI 10.1038/s43587-026-01159-2. Francesca Duncan at Northwestern University said the intervention could produce similar outcomes in premenopausal women.

Barbara Vanderhyden at the University of Ottawa said prolonging ovarian function could delay health impacts of menopause such as higher risks of osteoporosis and heart conditions. The researchers plan to deliver the drug more directly to the ovaries before testing it in people.