(Wired) - FOR MILLIONS OF drinkers, the scariest two words on a bottle of wine are “CONTAINS SULFITES.”

Sulfites comprise a range of sulfur compounds—particularly sulfur dioxide (SO₂)—that are a natural by-product of the fermentation process that work as a preservative against certain yeast and bacteria (which will quickly destroy a wine if they start to multiply). But fermentation alone doesn’t produce enough sulfite to preserve a wine for more than a few weeks or months in the bottle, so winemakers add extra in order to keep microbes at bay. Sulfites aren’t just in wine. Many, many foods ranging from crackers to coconut contain sulfites. Anything that’s at all processed is likely to contain at least some level of sulfites.

In 1986, the FDA identified sulfites as an allergen, following a rash of asthma cases reported around that time. Sulfites were promptly banned from raw fruits and vegetables, and as part of the warning label push in the late 1980s the feds required that sulfites be disclosed on wine labels if they could be detected at a level of 10 mg/L or higher. If you prove your wine has less than that, you can apply for an exemption—thus so-called “sulfite-free” wines exist. They are universally quite vile. Though many foreign producers include US warning labels, technically the rules only apply to domestic wines. Either way, sulfites are a regular part of winemaking around the world as a matter of necessity. Just because your bottle of Chateauneuf-du-Pape doesn’t have the warning doesn’t mean it isn’t full of sulfites.

And that’s how the hysteria over sulfites in wine got started.

The Headache Conundrum

Put simply, sulfites are to wine as gluten is to food. While the FDA says the overall prevalence of “sulfite sensitivity” is unknown, it notes that it is “probably low” and is most frequently associated with severe asthmatics. That hasn’t stopped all manner of people—many of whom are furiously typing out an angry comment below as you read this—from laying claim to sulfite sensitivity, arguing that the sulfites in wine cause a wide range of medical conditions. The big one: headaches.

Do sulfites cause headaches? Legions of drinkers say they do. Science says they don’t. (Same goes for MSG, by the way.) Here’s a look at the research.

A 2008 study in The Journal of Headache and Pain on alcohol and headaches said that even in individuals with asthmatic sulfite sensitivity, sulfites have not been shown to cause headaches. The study goes on to say that “On the other hand, there are many foods such as dried fruits, chips, raisins, soy sauce, pickles and juice fruits containing concentration of sulphites [sic] even ten times higher than that of wine.”

The Journal of Head and Face Pain noted in 2014 that “Sulfites were once linked to headache after wine ingestion. However, most of this belief is either speculative or in fact wrong, since the food and wine preservative sulfur dioxide (SO₂), called generically sulfite, although present in wines, is much more existent in common foods that do not trigger headache attacks, such as dried fruit… Moreover, recently produced organic wines contain lower levels of sulfites or, indeed, have none at all, but the persistence of the headache triggering potential remains. In addition, published literature has not yet established any links between the presence of sulfite and headache.” (In other words, studies have found that people complain of headaches just as much after drinking sulfite-free wines.)

That said, many people do experience headaches when drinking red wine, so much so that Red Wine Headache has been acryonmmed to RWH. While the science is as yet unclear, major suspects include histamine and tyramine, two natural chemicals that can mess with blood pressure and lead to headaches. (Fun fact: Red wines have more histamine, but white wines usually have much more sulfite.) There’s also the inconvenient argument that wine contains lots alcohol, which has a significant dehydrating—and thus headache-inducing—effect.

DIY Sulfite-Removal Systems

But let’s say you have an asthmatic sulfite sensitivity but still want to drink wine and want to get rid of the sulfites. Or maybe you still think sulfites are giving you a headache. Is there a way they can be removed from wine after it’s already in the bottle?

It turns out there is, and that method is far less high-tech than you might think. The solution lies in a familiar brown bottle in every suburban bathroom: hydrogen peroxide. Hydrogen peroxide oxidizes sulfites, turning sulfite into hydrogen sulfate, which does not cause the types of problems that are associated with sulfites. It’s long been said that a few drops of H2O2 in your wine will eliminate the sulfites altogether, at least in theory.