What is Myricetin?
Myricetin, also known as myricetol, is a naturally occurring compound that belongs to the group of chemicals known as flavonoids .
Flavonoids are known for their antioxidant properties. Myricetin, in particular, stands out in this group as it is a better antioxidant compared to other flavonoids.
A variant of myricetin (dihydromyricetin or ampelopsin) gives the oriental raisin tree its “anti-hangover” properties. The oriental raisin tree has been used as a hangover cure, as it reduces the alcohol levels in the blood .
Myricetin is also attached to many sugar storing molecules in plants (glycosides). Glycosides in flowers of Roselle are beneficial for patients with high blood pressure, as they reduce blood pressure.
Myricetin occurs naturally in many vegetables and fruits along with other edible parts of plants. Red wine also contains myricetin .
Some of the commonly available fruits and vegetables that are a good source of myricetin are:
- Oranges 
- Blueberry leaves 
- Japanese raisin tree (oriental raisin tree) 
- Grapes (grape seeds) 
- Broccoli 
- Cabbage 
- Peppers (red chili, green chili, bell peppers) 
- Garlic 
- Cashew (shoots) 
- Guava 
- French beans 
- Tomato 
- Apple 
- Green and black tea 
Myricetin works by disrupting cellular pathways. It interacts with enzymes and suppresses their activities (enzyme inhibition).
It inhibits phosphodiesterase enzymes (PDE), which are involved in setting up inflammatory responses against injuries or toxins .
Health Benefits of Myricetin
1) Myricetin Is Antioxidant
2) Myricetin Is Anti-Inflammatory
Myricetin prevented human platelets (blood cells) from clotting, which is an important step in the inflammation process .
It also suppressed protein kinases (enzymes that enable the function of other enzymes), many of which act as signaling molecules during inflammation .
Since it is a naturally occurring anti-inflammatory molecule, myricetin is also a possible solution for chronic inflammatory disorders like rheumatoid arthritis and atopic dermatitis .
3) Myricetin Has Anticancer Properties
DNA in normal cells have special genes called oncogenes, or tumor suppressor genes. These genes control cell division and prevent cancer . If DNA in normal cells undergoes oxidative damage and mutations in these genes occur, it may lead to cancer.
Although myricetin is a good antioxidant, it can also act as a pro-oxidant in the presence of certain ions such as copper [20, 21]. In this form (myricetin-copper complexes), myricetin is toxic to cancer cells causing cell death (apoptosis). Copper-myricetin complexes produce reactive oxygen species that break DNA in cancer cells .
Cisplatin, in combination with myricetin, increased inhibition of cancer cell growth and increased cell death compared to cisplatin by itself .
Myricetin has a chemopreventive potential for the following types of cancer:
- Cervical 
- Brain 
- Leukemia 
- Endometrial 
- Breast (by inhibiting the activity of aromatase enzyme) [24, 25]
- Prostate 
- Skin 
- Bladder 
- Pancreatic 
- Colon 
4) Myricetin May Help with Diabetes
In rats, myricetin treatment decreased high blood sugar by 50% within a couple of days of treatment .
In a study (RCT) of 42 diabetic patients, Blueberin supplement containing 50 mg of myricetin reduced blood glucose when compared to the control group .
5) Myricetin Protects the Brain
Progression of Alzheimer’s disease has been associated with an increased phosphorylation of tau proteins. Myricetin decreased this phosphorylation, and therefore, may slow down the progression of Alzheimer’s disease .
It also blocks β-amyloid aggregates formation, which is associated with Alzheimer’s disease .
6) Myricetin May Protect the Heart
When blood returns to tissues after periods of lack of oxygen, it can cause inflammation and oxidative damage to the tissue. This is known as reperfusion injury .
In guinea pigs, myricetin treatment also caused a 27% decrease in cholesterol deposition in blood vessels .
Myricetin also decreased toxicity induced by isoproterenol in rats. This shows a potential of myricetin for the treatment of heart attack .
7) Myricetin May Prevent Weight Gain
8) Myricetin Is Antimicrobial
Myricetin increases Cl‑ secretions in the tissue of the respiratory (breathing) tract. This thins the mucus in cystic fibrosis patients and helps the movement of cilia (hairs that clean trachea by moving mucus out of trachea). The cleanup of the trachea prevents infections by virus and bacteria in cystic fibrosis patients .
It also suppressed the enzyme reverse transcriptase in HIV, which is crucial for virus replication .
9) Myricetin May Protect the Skin
In cells, myricetin-3-O-β-rhamnoside (myricetin with an added rhamnose sugar) increased fibroblast (cells that repair wounds) migration to the wound site. This significantly decreased healing time .
10) Myricetin May Protect Eyesight
Cataracts are one of the most common eyesight problems of the elderly. Diabetes and oxidative stress can lead to the formation of cataracts. Due to myricetin’s antioxidant and glucose-balancing properties, it prevented cataract formation in rats .
Myricetin protects retinal (eye) cells. The anti-inflammatory properties may also help in relieving macular edema (swelling of the retina due to liquid buildup) .
11) Myricetin May Protect the Bones
Myricetin helps and promotes the maturation of osteoblasts (cells responsible for bone formation). This helps in increasing bone mass .
It also protects bone cells from oxidative injuries, especially in diabetes .
12) Myricetin May Help Thyroid Function
Iodine retention by thyroid cells makes myricetin useful in radioiodine treatment for thyroid cancer .
Other Effects of Myricetin
Myricetin and Reproduction
Exposure to myricetin increased sperm motility in the human ejaculate (sperm samples), which may help increase fertility .
Myricetin and Multiple Sclerosis
Myricetin and Pain
In rats, myricetin was effective at relieving pain .
Myricetin and Allergies
Myricetin acted as an anti-allergen in mice allergic to egg white .
Limitations and Caveats
There are not many human trials available for myricetin. Most of the available myricetin studies were performed in test tubes, cells, or animals. Therefore, take caution when using myricetin for its purported health benefits.
Research hasn’t shown any significant side effects of taking myricetin, however, myricetin often causes cell death even in cells exposed to low levels of UV radiations .
You should avoid inhaling myricetin because it may cause shortness of breath.
Protective gloves and goggles should be used when handling myricetin.
Myricetin causes skin, eye, and respiratory irritation .
Therefore, you should consult your doctor before taking myricetin.
Myricetin improved the uptake of tamoxifen (for cancer), doxorubicin (increased uptake only when taken orally to treat cancer), and losartan (to treat high blood pressure) .
The rate of increased uptake of drugs was directly related to the dose of myricetin.
In macrophages, myricetin treatment decreased CD36 production (expression) and blocked CD36 proteins that were already present on the cells, which prevented it from binding with oxidized LDL. The binding of CD36 with oxidized LDL is one of the reasons for atherosclerosis (hardened arteries) .
Most of the users are happy with the results they are getting. Users have shown satisfaction over the ability of myricetin to maintain blood pressure, weight, and blood glucose. A reviewer praised its long-term effectiveness: “I have been using the supplement for 10 years now. My type 2 diabetes hasn’t progressed even after 15 years of diagnoses like some of the other people I know.”
Some of the users had a neutral opinion after using myricetin as they weren’t sure if they were getting results specifically due to myricetin since they were using other supplements too.
No side effects were reported by any of the reviewers.