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Resveratrol A to Z

Resveratrol (res-ver-a-trol)

Resveratrol is a type of polyphenol that can be found naturally in a variety of sources including grapes, Japanese knotweed (giant knotweed), berries, peanuts, dark chocolate and tea.

The French Paradox

Resveratrol, a compound found in red wine, first gained publicity in the early nineties when the CBS television show, 60-Minutes investigated why people living in France, despite eating diets high in saturated fats, had lower rates of coronary heart disease than people living in the United States. The report concluded that a higher consumption of red wine may play a role in lowering coronary heart disease. Since then, researchers have pointed to resveratrol, a substance contained in grape skins (and other plants such as Japanese knotweed), as the compound with the possibility of preventing or delaying coronary heart disease and many other health conditions.
The potential benefits of resveratrol are based on hundreds of studies and include assisting with the cardiovascular system, liver, calorie restrictions, and mimetic and athletic endurance. Resveratrol has also been shown to protect against cell damage that can put people at a higher risk of cancer. It can help prevent joint disease, Alzheimer’s, aging, cataracts, macular degeneration, Lyme disease, neurodegenerative diseases, Parkinson’s disease, multiple sclerosis, and cell damage. Finally, resveratrol has been shown to have anti-aging and anti-inflammatory properties.
The potential benefits of resveratrol are based on hundreds of studies, and include assisting with the cardiovascular system, liver, calorie restrictions, and mimetic and athletic endurance; prevention against cancer, joint disease, Alzheimer’s, aging, cataracts, macular degeneration, Lyme disease, Neurodegenerative diseases, Parkinson’s, Multiple Sclerosis, and cell damage, as well as having anti-aging and anti-inflammatory properties.

Resveratrol Studies (Resveratrol Health Benefits)

Click on any of the links below to find out more about Resveratrol:


What Should You Know Before Purchasing Resveratrol?


It is not surprising that consumers are confused about resveratrol. Resveratrol is a general name for a product that is available in various prices and purities: 5%, 10%, 20%, 50%, and 99%. It’s all about labeling. If a manufacturer does not indicate the amount of trans-resveratrol on the label (and most do not), then there is no way of knowing the purity of the product, or if it has any health benefits at all. Resveratrol can provide great health benefits ONLY if it contains sufficient amounts of trans-resveratrol, the active ingredient and beneficial substance in resveratrol. “Pure resveratrol” does not mean pure trans-resveratrol.
If you purchased a questionable product, ask the manufacturer for COA (Certificate of Analysis) and/or for a USA third-party lab testing certificate.
If all manufacturers would disclose the purity content of their product, there would be no confusion at all. In principle, buying resveratrol should be as straightforward as buying gold: both are available in a variety of purities, but with gold, there is no confusion. Why? To protect the consumer, the law requires the dealer to indicate the purity content by stamping the purity on each item they sell (e.g., 5K, 14K, 24K, etc.). Unfortunately, the same law does not apply to dietary supplements and thus leaves the door open to fraud.
Since the FDA does not require the purity content of dietary supplements to be indicated on the label (or does not enforce its policy), it is not surprising that manufacturers who offer low-purity resveratrol do it solely for financial gain, and therefore do not disclose the purity content of their products on the Supplement Facts label. Instead, they use misleading descriptions such as “Extra Strength,” “Super Potency,” “High Purity,” “100% Pure Resveratrol,” “Maximum Strength” and other intentionally deceptive statements while offering low purity resveratrol. It is important to note that most resveratrol sold in the USA and abroad is of a low purity: 20%-50% or less.

Remember, if the Supplement Facts label does not clearly indicate the amount (or percentage) of trans-resveratrol content, then there is no way of knowing the product purity content, or if it offers any health benefits.
A classic example is a “resveratrol” product sold on Amazon that claims to be “100% Pure Resveratrol – 1000 mg Per Serving – Max Strength,” at an extremely low price. Despite its “purity” claim, the “Supplement Facts” label does not indicate trans-resveratrol content, and thus, there is no way to know the actual purity of this product. Although the seller claims the product “has been third-party tested,” neither the testing certification nor a COA (Certificate of Analysis) is posted or available. The price is too good to be true.
Every Supplements Facts label should indicate both the “total product” content AND the “trans-resveratrol” content. By providing both values, we can calculate the actual purity of the product in question. For example, a 50% pure product should be indicated on the label as “Resveratrol (Polygonum Cuspidatum Root): 500 mg Yielding 250 mg Trans-Resveratrol.” Or, “Standardized to 50% Trans-Resveratrol.”
Consumers should be aware that even though the initial cost of lower-purity resveratrol supplements is lower, the actual cost can work out to be the same and sometimes even significantly higher than the cost of pure trans-resveratrol. For instance, consumers who purchase supplements of 25% purity must take four times the dosage to achieve the same results as one dose of a pure trans-resveratrol product.
Below are samples of “Supplement Facts” labels. To emphasize the question of purity content, certain unrelated information (e.g., “Inactive Ingredients,” “Directions,” etc.), was purposely omitted from the sample labels below.
Label A
Label B
Again, when total resveratrol or trans-resveratrol content is not disclosed, it is impossible to calculate or establish purity. (Unless it indicated as “standardized to ‘x’ percent” as in the first two sample labels above.)
FDA Dietary Supplements Labeling Guide >>>


What is “Pure” Resveratrol?

“Pure resveratrol” refers to a product that should contain only TRANS-RESVERATROL, the active ingredient and beneficial substance in resveratrol. Purifying resveratrol is the process of isolating  TRANS-resveratrol from the rest of the plant.   Whatever is left are impurities that are being disregarded.  It is important to note that pure trans-resveratrol does not cause any side effects compared to lower-purity products. These often contain emodin and other substances or other parts of the plant that may cause gastrointestinal problems in sensitive individuals.
As a reference for consumers, the physical appearance of resveratrol from Japanese knotweed varies according to its purity and therefore may help distinguish between a high-purity and low-purity product. Pure resveratrol is white/off-white in color, and is (almost) odorless, while low-purity resveratrol is brown and has a strong, distinctive odor. The higher the purity, the brighter the color. Resveratrol obtained from grapes is very expensive to produce and is therefore only available in low purities of 5-8% trans-resveratrol content. (Unfortunately, some companies that offer low purity resveratrol add a high amount of rice-flour in order to brighten the product color).

Trans-Resveratrol Vs CIS-Resveratrol

Both trans-resveratrol and CIS-resveratrol are found naturally in grapes, Japanese knotweed, and other plants; however, only trans-resveratrol offers health benefits. Again, resveratrol products in CIS form offer no health benefits. High-purity resveratrol products always contain a high volume of trans-resveratrol, while lower-purity products contain greater amounts of CIS-resveratrol (and emodin) and lower amounts of trans-resveratrol (the beneficial part of the plant).


From Dr. Sinclair Study >>>


Side Effects – (Resveratrol 99% Vs Resveratrol 50%)

“Pure resveratrol” means the product is 99% pure trans-resveratrol, the beneficial, active ingredient of resveratrol. Resveratrol 50%, on the other hand, contains only 50% trans-resveratrol. The other 50% is made up of ingredients that are natural parts of the plant but which have no health benefits. These ingredients include CIS-resveratrol and emodin, which may cause gastrointestinal side effects such as stomachaches and diarrhea. The lower the purity of the product, the higher the emodin content and potential risk of side effects. These ingredients also account for the darker color and stronger odor of resveratrol 50%. Resveratrol 99% is white, has no odor and causes no side effects. Due to the purification process, resveratrol 50% typically costs about 40-50% less than resveratrol 99% (but would require double the dosage of pure trans-resveratrol to match its benefits).


99% Purity Capsules

99% Purity Capsules


50% Purity Capsules

50% Purity Capsules


Grape Resveratrol Vs. Japanese Knotweed Resveratrol

Most resveratrol sold in the United States and abroad is made of Japanese knotweed. Resveratrol made of grapes is NOT superior to resveratrol made of Japanese knotweed; this is purely a myth. Grape resveratrol is only available in purities of up to 5%-8% trans-resveratrol. Knotweed is available in up to 99%-100% purity. Pure trans-resveratrol (99%) made of knotweed does not contain emodin and does not cause any side effects.
Why the difference in purities between grapes and knotweed? It’s all in the cost. Unlike grapes, knotweed grows in the wild and contains higher concentrations of trans-resveratrol. Prior to processing, knotweed can be stored at room temperature, while grapes need to be kept frozen. It takes about 250 kilograms of grape skins to produce one kilogram of resveratrol that yields only 5% trans-resveratrol product.
Beware of products labeled “Made with grape resveratrol.” Most of those products are worthless. Usually, a minuscule amount (a few milligrams) of lowest-purity grape resveratrol is added to low-purity knotweed resveratrol, a product which is low in price but also ineffectiveness. Again, it’s another marketing gimmick to intentionally mislead consumers for the sole purpose of monetary gain. Another product that may be confused with grape resveratrol (or resveratrol) is grape-seed, which does not contain any resveratrol.


It’s clear that the source of resveratrol is not what matters, what is important is knowing the purity of the product you are purchasingRemember, it’s the amount of trans-resveratrol that counts, not the source of the product.

Micronized Resveratrol

“Micronization” is the name given to the process of reducing the size of a solid material. Some dietary supplements are water-soluble and therefore, their absorption rate in the body is higher than the non-water-soluble supplements. Since resveratrol is non-water-soluble, the only way to increase its absorption and bio-availability rate is to reduce the size of the particle. The smaller the particle size, the higher its absorption rate. Mega Resveratrol’s average particle size is less than 2 µm (<0.002 mm), compared to 170 to 220 µm (0.17-0.22 mm) of standard resveratrol. Clinical studies have shown that micronized particle size increases the absorption rate by up to 1000%.

Side effects and Dosage

Resveratrol has been used for many years and no safety issues have ever been reported. During the last few years, a number of clinical studies confirmed that taking pure trans-resveratrol in dosages of up to 6,000 mg daily is safe and does not cause any side effects. Unlike pure trans-resveratrol, lower purity resveratrol may cause gastrointestinal side effects due to the natural content of emodin which may act as a laxative in sensitive individuals. Pure trans-resveratrol contains no emodin.
As a reference, the dosage used in the Harvard study was equal to 23 mg per kg, or about 500 mg per 50 pounds of body weight. For example: A person that weighs 150 pounds would take 1500 mg daily. This is just a suggestion based on the study, not a rule. Based on recent scientific studies, 500 mg – 1000 mg of trans-resveratrol (depending on body weight) is the minimum daily amount that is needed to promote the benefits of this product for healthy individuals (an even higher dosage may be required for individuals with certain health conditions).
Resveratrol may enhance the effect of blood-thinning medications (e.g., Coumadin, Aspirin, etc.) and increase the risk of bleeding. Consult your healthcare provider before taking resveratrol. As with any other foods, an allergic reaction to resveratrol is also possible but very rare. Individuals with an allergic reaction to grapes, red wine or polyphenols are advised not to consume resveratrol. When starting a resveratrol regimen, always start with the lowest appropriate dosage and increase over a few days.

About Mega Resveratrol 99% Trans-Resveratrol

Mega Resveratrol 99 is a pharmaceutical-grade supplement, micronized and purified to a minimum of 99% pure trans-resveratrol.
Mega Resveratrol was a pioneer in introducing high potency resveratrol products to consumers and in setting the standards of voluntary third-party independent lab testing for purity and safety.
We offer premium grade natural resveratrol supplements delivered in a vegetarian capsule and in powdered form at an economical price.
At Mega Resveratrol, we are always trying to improve our products. For example, most dietary supplements and vitamins are made with “inactive ingredients.” These ingredients are added mainly to facilitate the manufacturing process but offer no health benefits. In some cases, these added ingredients may produce an allergic reaction or can even be generally unsafe for consumption. All of our resveratrol products are made with no excipient (inactive) ingredients added. That means all you get are vegetarian capsules that contain pure resveratrol with absolutely no additives, binders, fillers or preservatives (e.g., stearate acid, silica dioxide, etc.).
Our natural resveratrol products are encapsulated in the USA in a GMP facility regulated by the FDA. Every batch is tested for purity by an independent U.S. laboratory. Please refer to the Certification Page.
Mega Resveratrol is a proud supplier of pure trans-resveratrol products to pharmacies and research institutions in USA and abroad. See the About Us page for details. Our customer’s reviews are independently posted and may be viewed at Google Reviews Page.

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