If your hands and feet turn white with cold- called Raynaud’s Syndrome- Viagra may put the heart back in ‘em. Erectile dysfunction(ED) drugs relax constricted blood vessels in the penis by inhibiting an enzyme (phosphodiesterase type) crucial to the complicated business of maintaining proper blood vessels “tones”.

The spongy erectile tissue in the penis swells when blood flows in through dilated(opened) blood vessels. The erection is maintained by swollen tissue pressing on veins so the blood can’t escape.

People with Raynaud’s syndrome also have a problem with uptight blood vessels: The small blood vessels that supply their feet and hands go into spasm, usually in response to cold or occasionally stress. Because blood can’t get through, their fingers and sometimes toes become numb and painful. In severe cases, which usually involve connective tissue disease, Raynaud’s can result in the death of tissues and complications like gangrene.

In one study, 18 people with Raynaud’s were randomly assigned to take either a placebo pill or 50mg of sildenafil (Viagra) twice a day for four weeks. After a one-week “washout” period, those taking the placebo switched to sildenafil, and vice versa.

The volunteers symptoms improved when they were taking sildenafil but not when they were taking the placebo. Some tests showed why that might be so: The drug quadrupled blood flow through capillaries. These findings were reported in the journal Circulation late last year.

In another study, 40 people with Raynaud’s took 10mg of a different Ed drug, vardenafil(Levitra), twice a day for two weeks. About 70% said there Raynaud’s symptoms improved, and tests showed a big improvement in the blood flow in their fingers.

The studies were small. Many of the participants had secondary Raynaud’s, when the condition is the result of another health problem, such as lupus or rheumatoid arthritis. And Raynaud’s sufferers do ahve alternatives. The standard advice is to stay out of the cold as much as possible. Calcium-channel blockers or other medications taht relax blood vessels can be prescribed.

Easier and cheaper ways to avoid Raynaud’s syndrome is keeping your environment warm, warming your extremities in warm water, swinging your arms in large circles to increase circulation, using relaxation techniques such as deep breathing to control stress and quitting smoking if you smoke.

But come this winter, maybe the ED drugs will be something else for Raynaud’s sufferers to try.