A pregnancy hormone could prove a simple way to treat multiple sclerosis, after showing promise in a trial of 158 women with MS.

MS is a neurological condition that results from damage to the brain and nerves inflicted by the body’s own immune system. It affects 2.3 million people worldwide. Symptoms include extreme tiredness, blurred vision, muscle weakness and problems with balance and movement.

The symptoms of women with MS tend to ease when they are pregnant, but worsen again after giving birth. This could be because of a hormone called oestriol, which is only produced in significant amounts during pregnancy. The hormone is thought to help suppress the mother’s immune system to prevent it attacking the fetus.

Fewer relapses

Rhonda Voskuhl of the University of California, Los Angeles, and her colleagues wondered whether giving oestriol to people with MS who aren’t pregnant might also help with symptoms. They gave 8 milligrams of oestriol daily to 86 women with MS, along with their medication, Copaxone (glatiramer acetate).


The women had the most common form of MS, called relapsing-remitting MS, which results in periodic flare-ups of symptoms followed by recovery. After one year, they had 47 per cent fewer relapses than a control group that took Copaxone and a placebo.

After two years, the relapse rate was 32 per cent lower than the control group in the group given the hormone, suggesting the effects had plateaued. “We think the oestriol group had bottomed out, and there was nothing left to improve,” Voskuhl said, as she presented the preliminary results at the annual meeting of the American Academy of Neurology in Philadelphia last week.

Voskuhl also said that the women who were given the hormone treatment scored higher in cognitive tests. On average, scores were about 6 per cent better – or three points on the standard 60-point scale to measure cognitive ability after one year than those taking the placebo. This suggests that damaged brain cells may have been repaired.

Protective effect

Voskuhl says this tallies with studies on mouse models of MS, which show that oestriol reaches the brain and protects neurons from damage. It also fits with research suggesting that in addition to dampening a mother’s immune system during pregnancy, oestriol helps to protect the fetal brain from stress, such as lack of oxygen.

Voskuhl is now planning to validate the results in a larger trial. Until then, she warns against using off-the-shelf oestriol to treat MS. “I understand why women might want to try, but I can’t support it till the effects are proven,” she says.

Oestriol is not available in the US, but is sold in Europe as an ingredient of hormone replacement therapies given to postmenopausal women to prevent osteoporosis.

Walter Koroshetz, deputy director of the US National Institute of Neurological Disorders and Stroke in Bethesda, Maryland, is encouraged by the results but like Voskuhl, cautions against attempts at self-medication. “We have no idea if oestriol’s effects on MS are the same or different from other oestrogen formulations, and doses would be a pure guess,” he says. Nor do we know whether oestriol works on its own, or with MS medications other than Copaxone.

Male version

Based on experiments with mice, however, Voskuhl believes that oestriol could potentially work on its own, and this will form part of the forthcoming trial. If it does, it has the potential to become a cheaper alternative to current treatments, she says.

Oestriol-related treatments might work in men too, although testosterone might be a better candidate, Voskhul says. In men, testosterone is converted into oestrogens in the brain, and these are also thought to be protective against MS.

After about the age of 30, men produce about 1 per cent less testosterone each year, and this might account for why men predominantly begin to get MS in their mid-30s to early-40s, says Volkuhl.

She and her colleagues did a small trial of testosterone on 24 men in 2007, which reduced brain withering and improved the men’s cognition, but she says a larger study is needed to follow up on the results.