Skip to content
Seeking Health we will be closed on May 27th in observance of the holiday. We will resume normal business hours on May 28th.
Seeking Health we will be closed on May 27th in observance of the holiday. We will resume normal business hours on May 28th.

Is Quercetin an Antihistamine? In Short, No.

Is Quercetin an Antihistamine? In Short, No.

Can quercetin support seasonal wellness? Definitely!

But is it an antihistamine? No!

If you’re one of those people who keep asking, “Is quercetin an antihistamine?”...

In this article, we’ll talk about the differences of both, why quercetin is NOT an antihistamine, and why you should consider quercetin to support seasonal wellness.

All About Histamine

When your body comes into contact with any histamine trigger such as ragweed, pollen, dust mites, and/or pet dander, your immune system sends a chemical signal to the mast cells to release histamine.

Histamine protects your body from irritants. Think of it as a bouncer at a club.

The problem is that while this compound wants to keep you safe, its overreaction can cause a stuffy nose, watery eyes, and hives.

Worse, if your immune system overreacts to these environmental exposures, it can lead to a life-threatening condition known as anaphylaxis.(1)

You see, histamine is stored in mast cells in tissues and basophils in the blood.

Mast cells are a type of white blood cell that’s important in histamine release as a response to sensitivities.(2)

Meanwhile, basophils are another type of white blood cell that helps the immune system fight and protect it from pathogens, allergens, and parasites. It also secretes enzymes to boost blood flow and avoid blood clots.

Once the mast cells in your skin, nose, lungs, gut, mouth, and blood receive the signal, it sends out the histamine.

Histamine then increases the blood flow to areas where allergies are present, causing inflammation.

In this case, the immune system signals the other “bouncers” in the system to do the repair work.

Histamines, on the other hand, bind to receptors in the body that can trigger specific responses.

H1 receptors

When histamine binds to H1 receptors, which are found throughout your body, including smooth muscle cells, neurons, and blood vessels, it can cause itchy skin, flushing, and low blood pressure. It may also lead to anaphylaxis symptoms.

H2 receptors

The activation of H2 receptors, which are found in the cells in your stomach, can lead to headaches, stomach acid secretion, mucus gland stimulation, and bronchoconstriction.

H3 receptors

H3 receptors located in your central nervous system can regulate histamine release. They also help in the production of acetylcholine, dopamine, and norepinephrine neurotransmitters.

H4 receptors

Lastly, H4 receptors, which are found in hematopoietic cells and bone marrow, help deal with autoimmune diseases and inflammatory disorders.

Fortunately, antihistamines prevent histamine from binding to any of these histamine receptors, although this causes a wide range of sensitivity symptoms.

What is an Antihistamine?

Antihistamines are used to manage allergy symptoms caused by too much histamine.

There are different types of antihistamines that you can use.


First-generation oral antihistamines can easily cross the blood-brain barrier and work with the H1 receptors in the central nervous system (CNS).

This type of antihistamine has sedative properties.

First-generation antihistamines can reduce motor and cognitive function. Since they have sedative properties, they can make you feel drowsy.

Some people also report experiencing dry mouth and eyes, double vision, low blood pressure, rapid heart rate, and dizziness when taking first-generation antihistamines.

Second- and third-generation

Unlike first-generation, second and third-generation antihistamines do not have any sedative properties.

In fact, they cannot cross the blood-brain barrier according to the journal National Institute of Diabetes and Digestive and Kidney Diseases.(3)

Therefore, they don’t have any impact on the CNS, unlike the first-generation types.

They are also safer and more potent than first-generation types, so they are recommended for use by adults and children over 12 years old.(4,5)

However, some of the common side effects of second-generation antihistamines include coughing, headaches, sore throat, tiredness, vomiting, and abdominal discomfort.

What is Quercetin?

Quercetin is a flavonoid that gives colors to flowers, fruits, and vegetables.

It’s commonly found in the leaves and skins of plants such as apples, parsley, grapes, onions, and blueberries.

The name quercetin is derived from “quercetum,” a Latin word that means “oak forest.”(6)

Sunlight encourages more quercetin production. Therefore, an apple that gets direct sunlight has more quercetin than an apple that doesn’t.

Quercetin may also be referred to as a polyphenol and phytochemical. This means that it contains substances that are beneficial for humans to take.

For example, the flavonoid acts as a powerful antioxidant, meaning, it prevents free radicals from pairing so they won’t do any more damage to the body.

Moreover, quercetin naturally supports the body’s ability to stop mast cells from producing and releasing histamine.(7)

It helps stop human mast cell activation by blocking the entry of calcium ions, thus preventing the release of substances such as leukotrienes, histamine, and prostaglandins.(8)

No wonder why quercetin is considered one of the best options for supporting healthy respiratory and immune systems.(9)

In fact, several growing studies have reported the benefits of quercetin for supporting a healthy response to histamine and environmental exposures.

In the Journal of Pharmacognosy Reviews, in vitro and vivo studies reported that using quercetin supports seasonal wellness and its associated characteristics.(10)

Another test-tube and animal study published in the Journal of Molecule showed that quercetin helps support a healthy level of inflammation and healthy response to histamine.(11)

While over-the-counter medicines can provide relief, they also come with serious side effects. That’s why many people opt for alternative solutions to support a healthy immune system and allergic response.

In one study, researchers gave rats 50 mg/kg of quercetin for four weeks.

Similarly, another study published in the Journal of European Review for Medical and Pharmacological Sciences shows that taking quercetin consistently can support seasonal wellness.(12) 

Researchers worked with 66 Japanese test subjects with Environmental sensitivities.

They were divided into two groups. The first group was given 200 mg of quercetin daily for four weeks, while the other group was given a control product.

The results? After four weeks of taking quercetin consistently, the test subjects reported a better response to environmental irritants than the control group.

Apart from its ability to support seasonal wellness, the flavonoid quercetin also supports a healthy inflammatory response that can help the body deal with environmental irritants in a healthy way.

It supports the release of inflammatory mediators, such as leukotrienes and prostaglandins, for healthy inflammatory response.

So, if you’re still wondering, “Is quercetin an antihistamine?”

These studies go to show that quercetin is not an antihistamine.

It is a powerful natural plant compound that supports healthy histamine stability within mast cells.

Can you take quercetin with an antihistamine?

According to, taking quercetin along with Benadryl or other over-the-counter (OTC) antihistamines results in no side effects.(13)

However, this doesn't guarantee that no interactions can occur.

Moreover, medicines such as antidepressants and indigestion medicines can have negative interactions with quercetin.

Therefore, it’s best to speak with your doctor before administering quercetin along with any other drugs.

How much quercetin should you take?

You can get quercetin by eating fruits and vegetables rich in flavonoids.

Some examples of these foods are onions, kale, cherry tomatoes, apples, blueberries, and broccoli.

Onion provides 28.4- 48.6 milligrams of quercetin per 100 grams, so it’s a great option if you want to boost your levels.(14)

In fact, the bioavailability of quercetin compared to rutinoside in apples is only one-third of that of onions.

You can also take quercetin as a nutritional supplement.

According to the European Journal of Clinical Nutrition, it’s safe to take between 500-1,000 mg of quercetin per day.(15)

However, due to its poor bioavailability, quercetin doesn’t absorb into the body as needed.

In fact, researchers have discovered that quercetin’s bioavailability slowly decreases after 25 hours.(16)

Because of this, you need to take large amounts of quercetin by itself to support a healthy histamine response.

Alternatively, you can take the flavonoid along with other compounds such as bromelain and stinging nettle extract to help support its absorption.

The American Journal of Clinical Nutrition also recommends taking quercetin along with other flavonoids such as rutin and luteolin.

This is because they can produce a synergistic effect, regulating the body’s histamine response by supporting mast cells and healthy levels of histamine.(17)

Therefore, if you’re looking to supplement with quercetin, make sure it includes these compounds for higher absorption rates and effectiveness.

Seeking Health's Top Pick

Here at Seeking Health, we make sure that all our supplements contain the purest and most effective ingredients to support your health.

When it comes to supporting seasonal wellness, we have HistaminX to help you.

HistaminX from Seeking Health contains plant compounds that support healthy mast cell function and normal histamine storage and release.

HistaminX features the plant flavonoids quercetin, luteolin, and rutin to support healthy levels of histamine.

It also contains stinging nettle to support respiratory, mucus, and urinary membrane health, as well as glucoraphanin for a strong immune system, healthy detoxification processes, and mitochondrial support.

Moreover, it contains bromelain, a digestive enzyme that supports normal inflammatory and healing responses.

These nutrients work synergically to provide you with seasonal comfort, respiratory tract wellness, and immune system health.

Therefore, if you’re in search of a trustworthy product to support a healthy response to histamine, HistaminX can do the job for you.

For the best results, take HistaminX on an empty stomach.

This is because the food we eat can ruin the bromelain’s ability to break down histamine, as it can also break down the foods.

If you want to support your seasonal wellness, go for HistaminX.

Get your HistaminX with quercetin at Seeking Health now. Shop now.


  7. .

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Leave a comment

Comments must be approved before appearing

* Required fields