8 Side Effects of Eating Garlic

Nobody wants to hear their favorite food can be bad for them or causes side effects, but refusing to acknowledge the other side of food won’t make the side effects go away/ it good for you and everyone else. The same is true for garlic: while extremely healthy and well tolerated by a number of people, garlic can also be bad for your health, especially for the stomach. The adverse effects of garlic are directly proportional to the amount you eat, with raw garlic and garlic supplements producing the most side effects, followed by products of the likes of pickled garlic and others containing acidic liquids.

Is raw garlic bad for you? There is all this hype surrounding garlic and its wonderful health benefits that drives even people who can’t eat garlic for health reasons to force themselves to endure its side effects in the hopes of enjoying the benefits too. And while there are many reasons garlic is good for you, there are almost just as many reasons garlic is bad for you, especially if you are having stomach problems. Yes, you’ve heard it right: the benefits of eating raw garlic are mostly reserved for those with excellent digestive health and even then intake should be limited to a couple of cloves a day and garlic not eaten every single day, but rather infrequently.

Garlic bad for you

But the bulk of garlic side effects is reserved for those people who suffer from stomach conditions such as GERD, gastritis or stomach ulcers. They already suffer from inflammation of the esophagus and stomach lining and the irritant nature of garlic active constituents only served to accentuate that inflammation and worsen their symptoms. There is no reason to take garlic pills either. In fact, garlic supplements are even worse than raw garlic sometimes because they concentrate more of the active constituents in it and are thus likely to produce even more side effects. If you are a person in good digestive health, without a pre-existing condition, know that all the benefits you are looking to get from garlic, you can get them from eating raw garlic rather than taking garlic supplements.

If you are someone with digestive problems, then garlic is not a good food for you and you are likely better off eating some other food that provides the same benefits, but from different constituents. And to set your mind at ease, no,  garlic and onions are not the main reason our ancestors lived 100 years. What ancestors? All of them? Did they only ear garlic and onions? There is no proof whatsoever of all those people living to be 100 to have eaten garlic and onions all of their life. Actually, most centenarians admit to having lead a moderate lifestyle and ate a bit of everything, but always naturally grown produce, had access to clean water and clean air. This being said, here are the 8 side effects of eating garlic you should know about:

Garlic side effects

1) Bad breath

The reason for garlic breath is a flavor-giving constituent in garlic called allyl methyl sulfide. This is essentially an organic sulfur compound and is absorbed into the blood from where it is transported to the lungs and finally exhaled, resulting in bad breath as well as a bad garlic-like or ammonia skin odor. There is also another way garlic causes bad breath, via the stomach. If you eat garlic with other foods that cause air in the stomach, you will likely burp and exhale pungent garlic compounds. Garlic can further trigger acid reflux, causing gastric juices to rise into the esophagus and sometimes even as far as the back of the throat, resulting in bad breath.

2) Garlic body smell

Garlic is one of those foods that make you smell bad. In addition to garlic breath, eating too much garlic, and sometimes even as little as two cloves, can make you smell of garlic, vinegar or even ammonia. The skin and especially sweat retain the smell the most. The reason for garlic smell is, once again, the organic sulfur constituents in the cloves. The most pungent are allyl methyl sulfide, diallyl disulfide and allicin, but all are absorbed into the blood and from there eliminated through the skin pores, especially through sweat. Some people tend to be affected more severely by garlic smell than others. Usually, discontinuing consumption, washing well and trying to sweat the garlic metabolites out through exercise can help you get rid of the bad body smell faster. Although, because these organic sulfur compounds take longer to be metabolized, you may smell like garlic for longer that you’d expect. Read more about garlic body smell.

3) Acid reflux

Eating raw garlic can give you acid reflux and worsen an existing GERD. This is because the active constituents in it are extremely pungent and may act as irritants, triggering inflammation of the esophagus and stomach lining and leading to gastroesophageal reflux. Some people are more sensitive to sulfur compounds in foods and, for them, side effects may be stronger. Those who are more likely to experience ammonia or garlic body smell, heartburn, bad breath and diarrhea after eating garlic or flatulence that smells like rotten eggs may also be more prone to acid reflux from garlic.

Garlic acid reflux is a side effect most common in pregnancy. Because of the growing baby bump, a lot of pregnant women experience gastric reflux more often than usual. But eating foods with the potential to irritate the stomach lining such as garlic or onions can further accentuate the acid reflux during pregnancy. See more foods to eat and to avoid for acid reflux.

4) Heartburn

Eating raw garlic can cause heartburn. This is because of the pungent sulfur compounds in garlic which irritate the stomach lining and cause gastric juices to rise into the esophagus. Because they are erosive, gastric juices essentially irritate and inflame the esophagus lining, resulting in the strong burning sensation in the chest known as heartburn. Garlic supplements have the potential to cause more severe heartburn than raw garlic.

5) Makes gastritis worse

If you have gastritis, then one of the foods you absolutely need to avoid is garlic. This is because the pungent, volatile compounds in garlic have an irritating effect, working up the stomach and causing acid reflux. Garlic also contains fructans, carbohydrates which ferment and feed the good gut bacteria. But fructans also cause stomach gas and increase the chances of stomach acid escaping into the esophagus and causing heartburn and damage. Some people are more sensitive to fructans and will experience more severe side effects than others.

6) Indigestion and stomach upset

The first reason why garlic causes indigestion is because of its fructans content. Some people have an intolerance to fructans and eating garlic and other foods high in fructans can cause stomach cramps, bloating, gas, burping, flatulence, acid reflux, heartburn, hot flashes, feeling like you have a knot in your stomach, nausea and vomiting, all symptoms of indigestion. The stomach upset can also be caused by garlic worsening an existing gastritis or GERD. Raw garlic and garlic supplements are the most likely to cause indigestion.

7) Interacts with certain medication

It has been shown that eating moderate to high amounts of garlic or just eating a few garlic cloves a day, everyday or taking garlic supplements can interact with various medication. Garlic alters the effectiveness of anticoagulant medication and medication for cardiovascular disease, especially high blood pressure medication. Certain classes of antibiotics, including several antibiotics used to treat tuberculosis, antiviral medication for HIV and AIDS and medication for hyperglycemia and estrogen-based medicines are all affected by garlic consumption.

8) Allergic reactions and anaphylaxis

Lastly, garlic can trigger mild to severe allergic reactions in predisposed individuals. Side effects may range from mild skin rashes with redness and itching to skin burns, difficulty breathing, sweating, low blood pressure, dizziness and anaphylactic shock. Inhaling or smelling garlic powder can trigger an asthma episode. Other side effects of eating garlic include diarrhea and irritable bowel. The pungent, sulfur compounds responsible for the taste and smell of garlic are the ones responsible for most of the allergic reactions to the bulbous vegetable.

The digestive upset caused by garlic is worse in the following situations:
1) Eating garlic on an empty stomach. There are absolutely no benefits to eating garlic on an empty stomach. This can actually make things worse for anyone with digestive conditions as there are no other foods to absorb or dilute the problematic constituents.
2) Eating a garlic clove before bed. If don’t want heartburn and insomnia or a worked up stomach that will take days to recover, then don’t eat garlic right before bed. Also see these 11 Side Effects of Eating Onions.


Is it good or bad to eat garlic? There is only one correct answer to this question and that is that garlic is both good and bad for you. Garlic is bad for anyone with existing digestive conditions such as acid reflux or gastritis. While you may be able to eat one clove every now and then, the more garlic you eat and the more frequently you eat it, the more severe the side effects. If you don’t have any digestive conditions, the side effects you may experience will ultimately depend on how you eat garlic, whether it’s raw cloves, concentrated supplements, pickled or roasted garlic, and how much of it you eat. Of course, there are benefits, but in the end, the side effects of garlic can produce more damage than the benefits can do good, so you have to ask yourself if the benefits are actually worth the side effects or if you would be better off getting those health benefits from foods other than garlic.

This post was updated on Saturday / August 1st, 2020 at 4:01 PM