7 Grapefruit Seed Extract Uses, and the Risks to Know Before Using It

While human studies are generally lacking, many natural health practitioners and patients report grapefruit seed extract's ability to help fight infections when used topically or taken internally.

grapefruit seed extract

Grapefruit seed extract benefits include killing all kinds of infectious microbes.

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Grapefruit seed extract uses are numerous due to its action as a highly concentrated, natural general antimicrobial and antioxidant. Benefits include killing all kinds of infectious microbes—bacterial, viral, and fungal—at least in test tube and animal studies.[1,2]

What’s in Grapefruit Seed Extract?

The main compounds in grapefruit seeds thought to be responsible for its ability to kill infectious agents are chemical compounds (polyphenols) known as limonoids and naringenin. These intensely powerful compounds act as antimicrobials and antioxidants, not only killing dangerous microbes but protecting the body’s tissues against the excessive production of reactive oxygen species which occurs when these pathogens infect the tissues.

A grapefruit extract dosage may come in a number of different delivery forms and concentrations. Liquids and/or capsules can be used whether the infection is on the skin; in the ears, nose, or mouth; or in the gastrointestinal tract. Grapefruit seed extract (GSE) is also used as a preservative and antimicrobial in natural personal care products as well as by the food industry for food preservation.

grapefruit seed extract uses

Limonoids and naringenin are the main compounds in grapefruit seeds believed to be responsible for their ability to kill infectious agents.

Warnings About Grapefruit Seed Extract

Grapefruit juice and possibly other grapefruit products, including grapefruit seed extract, are known to interact with certain drugs and may lead to serious adverse reactions. Grapefruit inhibits certain enzyme systems within the body most often involved in drug metabolism. This increases blood concentrations of the drugs concerned, creating a risk of overdose and dose-dependent adverse effects. Grapefruit seed extract can sometimes cause skin irritation when used topically. The liquid grapefruit seed concentrates should always be diluted; never use full strength and avoid contact with eyes or other sensitive areas.

Also, in a report published in 2012, investigators from the Austin, Texas-based American Botanical Council found that many grapefruit seed extract products on the market today contain synthetic chemicals that aren’t listed on their labels. They report that any antimicrobial activities in grapefruit extract products is likely due to these synthetic additives, and not the grapefruit extract itself. Since the actual amount of these unlisted chemicals could vary widely and are unapproved compounds for internal use, some natural health practitioners recommend not taking GSE health products internally. If you’re considering the use of GSEin treatment of a chronic condition, make sure to consult your physician.

Grapefruit Seed Extract Uses

Among the multiple grapefruit seed extract uses are the following:

  1. Throat gargle (for colds and sore throats)
  2. Mouthwash (for gums and dental health)
  3. Nasal/sinus wash (for sinus infections and colds)
  4. Ear drops
  5. Digestive disturbances (including candida and traveler’s diarrhea)
  6. Skin wounds
  7. Fruit and veggie wash

In addition to grapefruit seed oil, liquid extracts, and capsules, some companies (e.g., Nutribiotics) make throat sprays, nasal sprays, ear drops, mouthwashes and gargles, toothpastes, shower gels, wound disinfectant sprays, and other personal care products containing grapefruit seed extract. Follow the label instructions for use.

How to Take Grapefruit Seed Extract Internally to Fight Infections

Grapefruit seed extract concentrated liquid and capsules should not be taken by children except under a doctor’s supervision. Adults can mix 10 drops of the liquid concentrate into a glass of water or juice (5 oz. or more) and drink, 1-3 times daily, with or without meals. Note that the extract is extremely bitter. To avoid the bitter taste, adults may also take one to two 250 mg capsules one to two times daily with or without meals.

Grapefruit extract can deplete normal flora (healthy “good” bacteria) in the gut when taken long-term. If you plan to take GSE for 3 days or more, it’s important to consume a probiotic supplement two hours before taking your GSE dose.

GSE Benefits Include Killing Candida and Treating Digestive Symptoms

Grapefruit seed extract is perhaps best known for its ability to treat digestive disturbances and kill pathogens, especially fungal pathogens like Candida albicans, in the gastrointestinal tract. One preliminary human trial investigated the effectiveness of grapefruit seed extract in people with symptoms of irritable bowel syndrome (IBS) and eczema. Subjects received either 2 drops of a 0.5% liquid concentrate twice a day or 150 mg of encapsulated GSE (ParaMicrocidin®) three times a day.

After a month, all of the subjects taking capsules experienced significant improvements in constipation, flatulence, and abdominal discomfort, as well as night rest, while 20% of the subjects taking the liquid experienced significant improvements in their IBS symptoms. Results found that there were no major grapefruit seed extract side effects. The fact that these patients’ digestive symptoms improved with grapefruit extract suggests that they actually had an infection in the gastrointestinal tract that was causing their symptoms rather than IBS. And in fact, the researchers tested the extract against different intestinal pathogens and found it was most effective against Candida species, a type of fungal infection, and some types of parasites.


This post was originally published in 2013. It is regularly updated. 


[1] Acta Pharm. 2004 Sep;54(3):243-50.
[2] J Altern Complement Med. 2002 Jun;8(3):333-40.
[3] Grapefruit Seed Extract: Benefits, Myths and Dangers

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Kathleen Jade, ND

Dr. Kathleen Jade is a naturopathic physician and served for many years as the Medical Director and Editor-In-Chief of Natural Health Advisory Institute. She has been licensed as a primary … Read More

View all posts by Kathleen Jade, ND

Comments Comments Policy
  • GSE is an awesome product – especially as a household cleaning/disinfecting agent. Use it to clean doorknobs, counters, cutting boards, toothbrushes, combs. And to disinfect non-organic fruits and vegetables, mix 20 drops in enough water to cover them and let them soak for a few minutes. Every house hold should have a bottle of GSE around the house.

  • Does Grapefruit seed extract interact with BREO(flute Adobe giro ate and vilanterol inhalation powder ?
    Also, with Xoponex HFA (levalbuterol tartrate inhalation Aerospl) ??

  • I take bisoprolol & hydrochlorathiazide, for hbp. Is it safe to take Grapefruit seed extract, l also have Diverticulosis which is the reason l am considering GSExtract, thanks, j.j.

  • GSE is the True alternative to Drugs like Cipro, Zithromax, etc. Its cured over 10 oral infections I had. Took it after I had a partial nephrectomy cause of Pain 3 weeks after surgery. Took
    1 AmoxyClav then 500 mgs every 12 hrs.

    I feel pain was an infection.

    Reports of killing tumors as well.

  • I am taking TAB Sandoz- Atorvastatin 20mg. Which tells me not to eat grapefruit or drink grapefruit juice at any time while taking this medication. So is it safe to use grapefruit seed extract?

  • Do NOT put directly on eye for conjunctivitis~research dilution as I do not know, but definitely don’t use full stregnth~

  • It is from my understanding that taking ANY thing along with grapefruit extract will & can lead to elevated concentrations of these drugs in your blood. I suggest if you are taking hbp meds that you should speak with your Dr. before you start taking grapefruit seed extract. Also do some research on natural cures for hbp.

  • Don’t pay attention to this totally BIASED, PRO Pharmaceutical junk article! This is a set up to make you THINK nature is not as good as a chemically invented synthetic drug that makes HUGE profits and typical of how they deceive the public. First they say, many GS extracts contain “synthetic chemicals” that are NOT listed on their labels and I’d like to ask “HOW do “they” get away with ignoring THAT regulation?” They also say that any antimicrobial activities in these extract products is likely due to these SYNTHETIC additives, and NOT the extract itself! The FDA would show up at their doors in combat gear if a company was caught putting anti-microbial “chemicals” in a product without approval/labeling! Then they mention some unknown “trial” that gave some patients 2 drops of a 0.5% (ONE HALF of ONE percent) grapefruit seed extract only TWICE a day vs. others who took a prescription of 150 mg of ParaMicrocidin®) THREE times a day. They specifically don’t tell you that these are NOT equivalent doses. If you ask me, the extract dose sounds way too weak to achieve any results. A typical dose is 100-200 mg. which is why only 20% had any relief. That’s like saying you should take 1/8 of an aspirin to get rid of a migraine! Use your head…get educated, everything is at your fingertips now.

  • i am looking for grapefruit seed extract in pill tablets, as lomg as there is VERY little resveratrol in it because resveratrol is a powerful antioxidant which thins out the blood too much.

  • LM- grapefruit seed extract is considered a supplement and therefore NOT regulated by the FDA. It is entirely possible other ingredients than what is on the label are in products that are considered a supplement. There are no rules for supplements, these are entirely unregulated. Your best bet is to buy a product that has the USP symbol. Supposedly this organization certifies that the product is exactly what is labeled, no more and no less. Also note that any product that is considered a supplement will have a disclaimer on the label, even if it also has the USP symbol.

  • As far as the comment about the FDA not allowing products to be sold without full discosure, then you are believing a lie. The FDA is so complacent they allow too many things. That is a one good thing about GSE, that’s pure, it can help restore our bodies from the things the FDA allows in our foods.

  • I bought the NutriBiotic maximum GSE liquid conentrate (29.5ml) is this the same thing as the grapeseed extract that you’re talking about in your website? Do I follow the same insructions in how to take it?

  • do you know that chewing one or two seeds of grapefruit seed in the morning aggitates the pancreatic production of insulin and lowers blood sugar

  • Please let us know whether Grape seed Extract can increase blood sugar levels and can be a threat for Diabetes in Future.
    Also Please let us know if it increases your blood Pressure

  • GSE Burn Grapefruit Seed Extract burn : Call Poison Control if pain too intense. I leave the debate up to others, but I feel it is my duty to report my GSE NIGHTMARE. Shame on GSE for not posting a big caution on bottle! After applying to skin, was up all night in torment, no exaggeration. SEVERE burning pain. It was torture. Water, soap, no relief. Called Poison Control, got good advice, did not stop agony but made it bearable until effect of GSE wore off: Find any food or body oil, vegetable or mineral, cooking (NOT motor oil, ok?), apply and massage into GSE burn area. This oil will mix/bond with the GSE, which is oily based. Make sure new oil is rubbed in well, let sit a few minutes. Now – wash area thoroughly with lots of soap, and rinse well with water. The new oil will carry away some of the GSE, just enough so you aren’t in agony. Then wait, it takes about 12 hours for the GSE to calm down. This is so urgent, it is the first time I have ever posted a rescue message like this. If I had found this it would have spared me agony!

  • It may be best to just eat an organic grapefruit… There’s no denying the results of a healthy diet. The white flesh of a grapefruit also contains pectin, which has a wide range of health benefits. If you suffer from a candida situation and want to try a safe alternative, you can purchase Grapefruit Vitality Essential Oil (FDA approved) and rub it on your tummy. It only costs $10, and research has also shown grapefruit may support weight loss as well. In fact, I wouldn’t be surprised, if there was a connection between obesity and candida, but that’s just a guess.

  • nealba —-I have been using this product for well over a decade. I am not affiliated with the manufacturer. And I have, once or twice used the product topically without diluting it. I will concur, in it’s undiluted state, it does burn. HOWEVER, the labelling of GSE CLEARLY states that it is a liquid concentrate and to dilute it. Shame on you for blaming the company for your error. In my opinion, GSE is an excellent product.

  • Something that needs to be corrected in this article: “Results found that there were no major grape seed extract side effects.” GRAPE seed and GRAPEFRUIT seed are two different things from two very different fruits. Please fix~!

  • I was exposed to strep throat a week ago, came home and dosed with over 15 drops of the Maximum strength GSE- ( I hadn’t read the label on the new bottle ! Afterwards, I called poison control and they assured me that I wouldn’t have too many side effects, although my tummy felt somewhat weird ! Almost a week later, I am having lots of gas, many BMs, and am trying to take probiotics, extra soothing foods, more water, etc. Will there be any serious side effects from such a large dose, taken internally?

  • A week ago, I took at least 15 drops of maximum strength GSE ( before I read the label ( external use only ! ) A week later, I am having lots of gas, many BMs, and was wondering what the overdose would cause ?

  • I want to know if GSE useful in cash. Breast patient.if yes what is dose I have ordered zenith nutrition grape seed extract 150 cap.bottle of 60 cap
    For my wife ,she is also having Blood pressure and Taking Nubeta 5 mg 1…O.D . Her Breasts carcinoma is grade2 please give answer urgently

  • I am taking it to treat rampant tinea corpus and some exzema. I take 250 mil pill morning and night. It is HELPING! I didn’t want to take the scary antifungal oral meds because of how hard they are on the liver. If you want to just have grapefruit you have to eat all of the fruit to get the same components. Buy grapefruit juice made from concentrate; they grind up the whole grapefruit to make this juice so you get all the benefits.

  • Kathleen,

    I’d like to know your opinion about this information from Jason Hawrelak, ND and herbalist in Australia who advises against using GSE:

    From the above document, Hawrelak states to avoid the use of GSE completely, that it is an extremely potent broad-acting antimicrobial that may decimate the GIT microbiota. He states that it is more active against beneficial members of the GIT microbiota than potentially pathogenic members. Also, that it has no tradition of use and is not a natural product (appears to be spiked with benzethonium, chloride, triclosan, and/or methylparababen) and displays human cytotoxicity in any dilution more concentrated than 1:256.

  • I just had a colonoscopy and it turned out that my whole colon is black. I have been taking 10 drops of grape fruit seed oil in 5 ounces of more of water twice a day for quite some time because of toenail fungus. Do you think that is why my colon was black. My toenail fungus is going away but I’m concerned that maybe I should stop taking the grapefruit seed oil. I do take probiotics but I don’t take it to hours before as someone else had suggested doing. Should I?

  • I used to believe based on the toxin theory such as espoused by Naturopathy hat the germ theory in allopathic medicine is exaggerated. I have instead discovered through hard experience that in fact the germ theory is more true than allopathic practitioners realize. I have cured my chronic IBS and tinnitus by tackling the germs through raw garlic in daily doses and citronella oil respectively. Now I am experiencing resolution of my rhinitis with GSE which so many users on the internet have testified on its efficacy. The germ theory is very correct; the problem is the overuse of artificial drugs many with serious side effects. Another problem is that allopathic medicine still fails to recognize some illnesses as being caused by germs – bacteria, fungi, viruses. Maybe someday it may discover that cancer is caused by some germs. In the meantime, let fortunate people who have found GSE make full of it and spread the word about this wonder remedy.

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