Sulfur is often suggested for natural mosquito repellents.
I've seen recommendations for taking sulfur pills, making sulfur creams, or applying sulfur powders.
According to the Colorado State University Extension, the sulfur content of cloves is the science behind garlic-based repellents or recommendations to consume garlic.
That said, I would not think eating a match head to be any way to get sulfur into your body.
A safety match head is mostly potassium chlorate fixed to ground glass.
A strike-anywhere match head will have phosphorous in it as well.
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Whether it's hogwash or not is besides the point in my opinion - the fact of the matter is match heads aren't designed to be ingested and therefore while consuming them may increase your sulfur levels which may help keep the bugs off, there's also a good chance you'll be consuming random poisonous chemicals.
Weighing it up, I think I'd take my chances with the bugs if that was all I had available!
In general I'd only suggest things like this in an emergency, but since "keeping the bugs off" is never a real requirement of an emergency situation, I'd never recommend it.
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If you ask civilians, you'll typically get responses along the lines of... "No way, there are dangerous chemicals!"
"No way, it just doesn't work!"
"
No way, you'll smell like ass for weeks!"
However, I (and many other military vets) can tell you that it does, in fact, work extremely well.
Military men (and recently maybe women) have been using this trick for decades, with no side-effects besides potentially smelling really awful depending on how much you consume.
Every MRE (Meal, Ready-to-Eat) comes with a book of matches handy, which is why the trick is so convenient.
One match-head per month will typically be sufficient to keep insects off of you, with no noticeable stink either.
If you need more potency, consume more regularly, maybe weekly or even daily - just keep in mind that more match heads = more stink.
Yes, potassium chlorate is a toxic chemical.
However , it is not contained in nearly high-enough quantities to be harmful unless you're slamming an entire pack of matches (and maybe not even then).
Phosphorus, the final chemical ingredient in match heads, is an element essential to your bodily functions, and represents 1% of your body mass.
Final disclaimer: as far as I know, only strike-on-the-box safety matches will always have the antimony (III) sulfide in them that makes the trick work.
Strike-anywhere matches may not contain this element, and so might just do nothing at all.
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Being a military vet from Vietnam, I've used this and I still use it.
Every year in the summer in Tennessee, when the mosquitoes come out it works very well for me.
Others may not be able to handle the taste.
Talking to non vets who haven't used it will tell you I'm not chewing on a match.
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The first time I tried this was at Fort Chaffee and the chiggers were so bad that people were laid out in sick call with bites all over their bodies.
Me and my buddies were "the communist forces" which meant little amenities...
we slept in the tall grasses for 7 days.
Every day I ate a match head and never once was bit.
This works.
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I have heard that eating the tips off a few match heads can help keep the bugs off of you. Supposedly you sweat out the sulfur and it repels the bugs. Has anyone else heard this or is there any truth to it? Is it harmful? Would garlic work better?   Note: I have this on and off for years from random people and always assumed it was hogwash.
Eating Matches to repel insects?
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<prevention><bugs>
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Some military veterans testify that eating one match head per month as a method of repelling insects works. Of course, match heads are not designed to be eaten and may involve eating hazardous chemicals. While the common view is that martch heads contain dangerous chemicals, veterans find that this works very well.
Veterans find that this workes extremely well. It's commonly held that match heads contain dangerous chemicals.