What is Naringin?

Vasanth S.

Naringin is the chemical compound in grapefruit that is responsible for its bitter taste. It is classified as a phytochemical, which is a naturally occurring plant compound with potential nutritional benefits. Specifically, naringin is a water soluble flavonoid. It has been studied for its potential antioxidant and anti-carcinogenic properties, as well as its effects on enzyme activity in the digestive tract. Supplements containing naringin are typically used to enhance the effects of other drugs.

Naringin may be used to enhance the effects of other drugs.
Naringin may be used to enhance the effects of other drugs.

The chemical formula of the compound is C27H32O14. It has a molecular weight of 580.53 and in its purest form, the compound appears as a yellow powder. Chemically, it is a conjugate of a sugar molecule and naringenin, which is another flavonoid present in grapefruit.

Naringin is what gives grapefruits their bitter taste.
Naringin is what gives grapefruits their bitter taste.

Generally, flavonoids protect cells from molecules that contain reactive oxygen atoms, commonly called free radicals. Usually, flavonoids reduce the damaging effects of free radicals by stimulating the production of glutathione, which is a strong anti-oxidant. Flavonoids can also increase the effectiveness of vitamin C as an anti-oxidant. In addition, flavonoids play a role in inflammation control by moderating certain cells of the immune system. They can also inhibit the activity of certain types of viruses, including the herpes simplex virus.

Blood pressure medication that is taken with naringin may cause adverse reactions.
Blood pressure medication that is taken with naringin may cause adverse reactions.

The main use of supplements containing this substance, in addition to preventing free radical damage, is to increase the bioavailability of nutrients. Basically, the amount of nutrients absorbed by the body is limited. A food may contain a certain amount of a vitamin, but a portion of it will not be absorbed by the body.

To increase the amount of nutrients absorbed by the body, the activity of several enzymes within the digestive tract is decreased by naringin. This prevents the breakdown of nutrients, allowing more to be absorbed into the blood stream. Usually, supplements are consumed while eating or along with other nutritional supplements to increase their absorption.

Generally, 25 mg of naringin is enough to increase the bioavailability of nutrients and drugs. The supplement is available in a pill, capsule or liquid form. Most of the benefits of the compound can be gained by drinking grapefruit juice.

Since the compound decreases enzyme activity in the digestive tract, the metabolism of drugs is also affected. The concentration of drugs in the blood generally increases when taken with naringin, which can lead to unexpected side effects. For example, a higher concentration of drugs designed to treat high blood pressure may lower the blood pressure to a point that causes fainting.

Naringin decreases enzyme activity in the digestive tract.
Naringin decreases enzyme activity in the digestive tract.

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Discussion Comments


Grapefruit also contains a large amount of fiber which is something that is good for your digestion. And something most of us don't get enough of.

There have been studies showing that naringin has anti-inflammatory properties and helps with wound healing by helping to produce new blood vessels in the wound area.


Could you point me in the direction of the study that suggests 25 mg of naringin is enough to increase the bioavailability of nutrients and drugs please?


It is interesting to know why grapefruit is good for you. To know that it helps me absorb the food I eat is another good reason to include it in my diet. I always try to eat the fruit that is in season. Not only does it taste better, but is usually cheaper too.

I look forward to the fresh grapefruit during the winter months. If the grapefruit is good and juicy I don't even put any sweetener on it. If I do want it to taste a little sweeter, I will drizzle some honey on it.

I also enjoy drinking grapefruit juice. Both the pink and white grapefruit juice is good, but the pink is a little bit sweeter. The next time I have a glass of grapefruit juice at breakfast, I will remember why it is so important.


@cmsmith10- I am also on the Duragesic (Fentanyl) patch. I read the same warning. I asked my doctor why I could not drink grapefruit juice or even eat grapefruit while on the patch. She told me that grapefruit juice inhibits CYP3A4 (the enzyme that breaks down the medication). If you drink grapefruit juice while wearing the patch, it can cause an increase in the fentanyl plasma concentration. In other words, it could cause too much of the medication to be delivered at one time.

My sister works as a drug counselor and said she has seen many people abuse Fentanyl patches by drinking large amounts of grapefruit juice with the patch on. I have had two clients that overdosed and died from this. Something as simple as grapefruit juice leading to cardiac arrest.


I was recently diagnosed with fibromyalgia. Often times, the pain is so severe that I have trouble getting out of bed. My doctor prescribed me Fentanyl patches for pain.

It is meant to stay on for three days at a time to control pain. I was reading the drug information sheet and I saw where it said to never drink grapefruit juice while wearing the patch. Does anyone know why? It didn't state the reason. It just said not to do it. I am just curious because I love grapefruit and grapefruit juice.


I am going to start drinking grapefruit juice now. I had no idea that it could help me get so much more out of food!

I admit that I don’t eat as many nutritious foods as I should. However, amongst the ramen noodles, bologna, and snack cakes that I consume, I try to include at least one fruit and one vegetable a day. Usually, that fruit is an orange or a banana, and the vegetable is broccoli or carrots.

I am thrilled that there is something out there that can enhance the little bit of nutrients I get each day. I’m also happy that all I have to do is drink some juice to make it happen!


High blood pressure medication and grapefruit are indeed very dangerous together. My brother-in-law was taking several medications to control his blood pressure, but his doctor didn’t know that he had a habit of eating two grapefruit a day.

When his doctor placed him on his latest extra blood pressure medication, he ate his two grapefruit the next day as usual. After the last grapefruit, he became very lightheaded. He took a few steps and fainted.

He hit the ground and suffered a concussion. My sister took him to the hospital, where they found out about his grapefruit habit. They explained what naringin had done and advised him to stop eating them.


It’s a good thing that I’m not taking any medications, because I have to drink grapefruit juice at work almost every day. I am a party planner and a caterer, and I have to taste punch that my company makes for weddings and showers before we send it out to the parties.

Almost all of the punches we make include grapefruit juice. We frequently mix it with ginger ale or lemon lime soda and sherbet.

It’s good to know that the naringin will increase my absorption of nutrients. I eat lots of healthy foods, and I’m glad I’m getting the most out of them.


This article has solved a mystery for me. I am on a clinical study drug to treat polycystic kidney disease, and it is called Tolvaptan. My study director told me not to eat any grapefruit or drink any grapefruit juice while on the drug. That was fine with me, because I don’t like the bitter taste, but I always wondered why I had to avoid it.

Now I see that the naringin in grapefruit would increase the amount of the drug in my system. Since it is in the study phase, not all of the side effects are known yet, and an increased dosage could cause something very bad to happen, for all they know.

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