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 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]
Uses | How To Take | Benefits
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 Side Effects and Warnings
What medications interact with 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. Common medications that may interact with grapefruit include blood thinners, statins, drugs that treat abnormal heart rhythm, and antihistamines.
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.
Can grapefruit seed extract be harmful?
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 GSE in treatment of a chronic condition, make sure to consult your physician.
Grapefruit Seed Extract Uses
Grapefruit seed extract can be good for many health benefits. Among the multiple grapefruit seed extract uses are the following:
- Throat gargle (for colds and sore throats)
- Mouthwash (for gums and dental health)
- Nasal/sinus wash (for sinus infections and colds)
- Ear drops
- Digestive disturbances (including candida and traveler’s diarrhea)
- Skin wounds
- 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.
Grapefruit Seed Extract Benefits (Including 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.
 Acta Pharm. 2004 Sep;54(3):243-50.
 J Altern Complement Med. 2002 Jun;8(3):333-40.
 Grapefruit Seed Extract: Benefits, Myths and Dangers
Grapefruit seed extract benefits include killing all kinds of infectious microbes.
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