Quercetin and Bromelain Supplements: Benefits and Reviews 2021

What Is Quercetin?

Quercetin is an antioxidant that belongs to a class of water-soluble plant substances called flavonoids, which are present in certain fruits and vegetables. According to an article in Current Research in Nutrition and Food Science, the bioavailability of quercetin absorbed by your body varies, depending on the source where you get it, as well as your individual body’s metabolism of it. Sugar and dietary fat and fiber also affect it.

While the best way to get quercetin is through your diet, it also is available in supplement form, as pills or capsules. Sometimes, quercetin in supplement form is packaged with bromelain, an enzyme found in pineapples, because both have anti-inflammatory properties (Quercetin & Bromelain for inflammation). Most dietary supplements contain a chemical compound, aglycone, which is the free form of quercetin.

When looking for and using quercetin supplements, it’s important to maintain a nutritious, balanced diet with fiber and healthy fats in it, as research shows that accumulation of quercetin in the body is dependent on “factors such as glucose moieties, solubility, human factor, vitamin C status and food matrix.”

Specifically, research also says that quercetin supplementation is best achieved when consumed with a fat-enriched diet.




There are foods high in quercetin that you can add to your diet. Arguably, red onions are some of the most potent sources of quercetin; one study found that absorption of onion-derived quercetin was 52% compared to only 24% in supplement form. In fact, onions can give you three times the amount of quercetin than you’d get from apples. Other food sources that are high in quercetin include:
  • Organically grown apples, grapes and tomatoes
  • Dark cherries and dark berries like blueberries, blackberries and bilberries (eaten in moderation)
  • Cocoa, unsweetened
  • Hot green chili peppers
  • Lingonberries

Benefits of Quercetin

Quercetin has been linked to the following health benefits:
  • Possessing anti-inflammatory, antioxidant properties that can help combat certain diseases. One study found that 500 mg of quercetin a day could improve symptoms of rheumatoid arthritis.
  • Helping prevent cancer cell growth from breast, colon, prostate, endometrial and lung.
  • Counteracting allergic reactions and helping with immune responses.
  • Helping to prevent osteoporosis
  • Addressing cognitive decline, including Alzheimer’s and dementia.
  • Assisting in control of blood pressure. A study in 2002 found that quercetin can have vasodilator effects.
  • Potentially helping to lower blood sugar levels. One study found that dosages of 500 mg per day “significantly reduced” fasting glucose levels.

Quercetin and Vitamin C for COVID-19?

There is evidence that vitamin C and quercetin co-administration exerts a synergistic antiviral action due to overlapping antiviral and immuno-modulatory properties and the capacity of ascorbate to recycle quercetin, increasing its efficacy.

For prevention, the Front Line COVID-19 Critical Care Working Group, FLCCC recommends (updated December 17th, 2020):
  • Vitamin D3 — 1000–3000 IU/day. Note RDA (Recommended Daily Allowance) is 800–1000 IU/day. The safe upper-dose daily limit is likely < 4000 IU/day. [1-22] Vitamin D insufficiency has been associated with an increased risk of acquiring COVID-19 and from dying from the disease. Vitamin D supplementation may therefore prove to be an effective and cheap intervention to lessen the impact of this disease, particularly in vulnerable populations, i.e. the elderly, those of color and obese.
  • Vitamin C - 500 mg BID (twice daily) and Quercetin 250 mg daily. It is likely that vitamin C and quercetin have synergistic prophylactic benefit. Quercetin should be used with caution in patients with hypothyroidism and TSH levels should be monitored.  
  • Melatonin (slow release): Begin with 0.3 mg and increase as tolerated to 2 mg at night. 
  • Zinc: 30–50 mg/day (elemental zinc). Zinc lozenges are preferred.
  • B complex vitamins
  • Ivermectin for prophylaxis in high-risk individuals (> 60 years with co-morbidities, morbid obesity, long term care facilities, etc). 0.15–0.2 mg/kg Day 1, Day 3 and then weekly for 10 weeks, followed by biweekly dosing. (also see ClinTrials.gov NCT04425850). NB. Ivermectin has a number of potentially serious drug-drug interactions. Please check for potential drug interaction at Ivermectin Drug Interactions - Drugs.com. The most important drug interactions occur with cyclosporin, tacrolimus, anti-retroviral drugs, and certain anti-fungal drugs. 
They also recommend monitoring your oxygen saturation with a pulse oximeter and to go to the hospital if you get below 94%. The medical evidence to support each drug and nutrient can be found under “Medical Evidence” on the FLCCC’s website.

Quercetin, Zinc and Vitamin C - Dr Zelenko's Protocol for COVID-19

According to Dr. Zelenko, the best over the counter substitute or natural alternative to hydroxychloroquine is quercetin. Here is his tweet from Sunday, August 16, 2020. Below is the print screen of his tweet.

Dr Zev Zelenko Hydroxychloroquine Substitute OTC for early COVID 19 MyNaturalTreatment.com
When hydroxychloroquine is not available, Dr. Zelenko recommends the following OTC treatment in the early stages of COVID-19 and quercetin as a natural alternative to hydroxychloroquine. He recommends this treatment immediately after you are tested positive and with symptoms.
  • Quercetin 500 mg – 3 times a day for 7 days.
  • Zinc 50 mg (elemental zinc) – 1 a day for 7 days. 
  • Z-pack/Zithromax 500 mg or Azythromicin – 1 day for 5 days. 
  • Vitamin C 1000 mg – 1 a day for 7 days.
As a prevention treatment, Dr. Zelenko recommends the OTC alternative to hydroxychloroquine above without the antibiotic (azythromicin). His prophylaxis for COVID-19 is the following:
  • Quercetin 500 mg / once a day.
  • Zinc 25 mg (elemental zinc) / once a day.
  • Vitamin C 1000 mg / once a day.

What is Bromelain?

Bromelain, or pineapple extract, is a compound made up of proteases normally found in pineapples. Although it is widely known for its ability to aid in digestion and protein breakdown, its use far transcends these functions and can actually offer a lot more. The good news is that it's available in the market as a supplement and as an aid for disease treatments.

The history of bromelain is heavily linked to pineapple because it is the only known major source for this group of enzymes. First discovered in 1891 by chemist Vicente Marcano and then subsequently elaborated by Russell Henry Chittenden, another chemist, bromelain was first called "bromelin," and described as the "proteolytic ferment of pineapple juice."

Its first primary source was the pineapple fruit, before it was discovered that the mature pineapple stem had much more concentrated bromelain content.

Through the years after its discovery, the production of bromelain has broadened. Its commercialization has led manufacturers into developing faster extraction techniques for large-scale production and purification. Today, bromelain supplements are used for numerous health approaches.

These uses have been observed to be dependent on the time when it is taken. For example, if taken after a meal, bromelain may help promote better digestion and absorption, but when taken on an empty stomach, it can help alleviate inflammation.(Daily Mail)

Related: BROMELAIN AND CURCUMIN: CAN THEY HELP AGAINST CORONAVIRUS?

Benefits of Bromelain

As a protease enzyme, the primary benefit bromelain has is improving protein absorption. However, bromelain has been widely used to promote healing and assist in the treatment of numerous diseases. For example, if you're suffering from chronic inflammation or from sports injuries, consider taking bromelain supplements to help your body recover. Other bromelain benefits that you'll get from this supplement include:

• Reduces inflammation and swelling — Bromelain may help alleviate symptoms of osteoarthritis and rheumatism. It's also used to help in sprain and strain recovery by reducing swelling and promote tissue healing. For people who are currently on arthritis medications, consider switching to bromelain for a more natural alternative.

• Improves immune function — Studies show that bromelain promotes a healthy immune system by regulating numerous inflammatory proteins during periods of cellular stress.

• Speeds up wound healing — The use of bromelain post-surgery has been observed to promote soft-tissue healing and reduce bruising. Patients who took bromelain also had shorter wound healing time compared to patients who did not.

• Relieves sinusitis symptoms — Sinusitis refers to the inflammation of the inner lining of the sinuses, which is usually caused by infections, nasal problems or allergies. Bromelain is a known supplement for relieving sinusitis symptoms. Together with quercetin, bromelain can help alleviate sinus inflammation, with quercetin functioning as an antihistamine. 

• Promotes blood flow — Bromelain helps in promoting healthy blood flow by reducing platelet aggregation in the arteries and lowering the chances of clots forming. This may lower your risk of developing atherosclerosis and other cardiovascular diseases.

There are also claims that bromelain can help induce menstruation by softening the uterine lining. The increased blood flow also supposedly helps in the prevention of menstrual cramps.

Because of the impressive components of bromelain, it's not surprising that it's been utilized in treating or reducing the severity of disease symptoms. While it is usually prescribed or recommended for patients who have undergone surgery or people suffering from chronic sinusitis, bromelain can also be used in other ways. These include:

• Topical application for burns — Studies suggest that bromelain can help remove dead skin cells from third degree burns and assist in burn healing in first and second degree burns. For severe burns, do not apply any bromelain ointment without a physician's supervision.

• Indigestion and heartburn — Taking bromelain has been known to assist in easing indigestion and bloating, especially when taken with other supplemental enzymes.

• Soothing balm for insect bites and stings — Applying bromelain directly to insect bites and stings may lessen inflammation and discomfort.

• Meat tenderizer — Pineapple has been used in cooking to soften meats. Today, bromelain is sold in powder form as a meat tenderizer and is usually combined with papain, an enzyme found in the papaya plant. In fact, bromelain is such a strong meat tenderizer that chefs and cooks claim it can turn meat into mush if left marinated for longer periods of time.

Quercetin and Bromelain Supplements on Amazon

1. Now Foods Quercetin with Bromelain


$30 - $35 > Check Price (available)

A two-pack of top notch bromelain-enhanced quercetin from a giant in the health supplement industry. Reliable quality from a trustworthy brand.

Each capsule contains 400 mg of quercetin and 82.5 mg of bromelain. Do take note that their suggested usage is 2 capsules twice daily. Meaning the total daily dosage of quercetin will be 1,600 mg.

Daily value (DV) for quercetin not established.

BestReviews.com: Not suitable for those with pineapple allergies.

Amazon Best Sellers: #1 Best Seller in Bromelain Nutritional Supplements. 4.7 out of 5 overall rating with more than 5,000 customer reviews.

2. BlueBonnet Super Quercetin


$36 - $40 > Check Price (currently unavailable on Amazon)

A potent blend of antioxidants and natural ingredients to ease allergies and boost immune response. Non-GMO and free of common allergens.

Amazon Best Sellers: #21 Best Seller in Flavonoid Vitamin Supplements. 4.8 out of 5 overall rating with more than 190 customer reviews.


Supplements you can purchase from Amazon for COVID-19 prevention based on the FLCCC prevention protocol >

Update: Many of the products do go out of stock on Amazon. This list will be updated from time to time. 

Here is the list of nutrients and their respective directions based on the FLCCC and Dr Zelenko's prevention protocol.
  • Nature's Bounty Vitamin D3 - 2,000 IU > One dose daily (Amazon)
  • Nature's Bounty Vitamin C - 1,000 mg > One caplet twice daily (Amazon)
  • Now Foods Quercetin - 400 mg > One capsule daily (Amazon)
  • Nature's Bounty Melatonin 5 mg > One tablet before bedtime (Amazon)
  • Nature's Bounty Zinc 50 mg/day > One caplet daily (Amazon)
Be aware that most of the dosages are above the recommended daily value and therefore should not be taken on a long term basis. 

You might need this: Pulse Oximeter > Amazon Best Sellers

Disclaimer: The information on this website is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice. It is intended as a sharing of knowledge and information from the research and experience of third party sites. If you are pregnant, nursing, taking medication, or have a medical condition, consult your health care professional before using products based on this content.

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