The Health Sciences Institute is intended to provide cutting-edge health information.
Nothing on this site should be interpreted as personal medical advice. Always consult with your doctor before changing anything related to your healthcare.

Keeping mosquitoes at bay with vitamin B

The placebo effect might relieve a headache or reduce depression symptoms…but could it actually repel mosquitoes?

My friend Terri told me that when she was young she used to get “eaten alive” every summer by mosquitoes. But one summer, before she left for summer camp, her mother gave her a bottle of vitamin B1 supplements and told her to take them every day to repel mosquitoes.

That summer…not a bite. Not one single mosquito bite.

Terri’s experience is not unusual. A few years ago I told you about an HSI member named Howard who wrote to share a similar success story using B1 and garlic tabs.

But is there any real evidence to back up these claims?

When I went looking I found many testimonials like Terri’s and Howard’s, but just one study. And this appears to be the only human study, because references to it (and it alone) cropped up again and again.

The trial comes from the University of Wisconsin, published six years ago in the Journal of the American Mosquito Control Association.

Results: A supplement of B complex (not just B1) had “no effect” in repelling mosquitoes.

But instead of asking all the subjects to spend a couple of summer evening hours sitting on a lake shore, the researchers collected “volatile skin components,” and exposed these samples to mosquitoes in glass vials.

So it’s not exactly a “gold standard” study.

Until we get better research, you can’t go wrong testing a B1 supplement for yourself. This nutrient — also known as thiamin or thiamine — helps maintain nervous system and muscle function, and plays a role in carbohydrate metabolism.

The U.S. RDA for B1 is 1.2 mg for adult males and 1.1 mg for adult females. Which is actually hilarious — as if that thin slice of a milligram would make the slightest difference.

B1 is quickly eliminated from the body, so most people will be in no danger if they significantly exceed the RDA. In fact, Dr. Spreen notes that many supplements contain as much as 100 mg of B1.

That should make mosquitoes everywhere begin to shudder…

“Testing Vitamin B as a Home Remedy Against Mosquitoes” Journal of the American Mosquito Control Association, Vol. 21, No. 2, June 2005,

Get urgent health alerts, warnings and insights delivered straight to your inbox