Grape Seed Extract: Benefits, Side Effects, Best Time to Take It & More

Grape Seed Extract

(Grape Seed Oil)

Evidence: High
Possible Benefits: Reasonable
Safety: Very High

What is grape seed extract?

Grape seed extract, also known as grape seed oil, is an extract made from the seeds of wine grapes. The seed extract is often used as a supplement for its antioxidant properties but can also have various other beneficial effects. This article is about the main benefits of grape seed extract, its potential side effects, the best time to take it, and more.

Possible benefits

All of the potential benefits mentioned below are dose-dependent. As with other adaptogens, there is a sweet-spot dose that allows you to get most of the benefits without causing meaningful side effects or tolerance buildup in the body. We will discuss the best dosing protocol later in this article.

Major benefits

Increased blood flow – Notable and reliable increases are seen with high-dose supplementation (600 mg/d). The supplement was also shown to reduce some of the problems associated with poor blood flow, such as leg swelling.

Minor benefits

Slower heart rate – A small reduction in heart rate was found in people with metabolic syndrome. Whether or not this benefit applies to healthy people is not yet clear.
Reduced blood pressure – One meta-analysis found that the average reduction of blood pressure in people who take standard doses of grape seed extracts is 1.54 mmHg. This reduction is rather small but reliable.
Reduced total cholesterol levels – This benefit is tiny and unreliable. It also might not apply to doses below 600 mg. The supplement does not impact HDL cholesterol levels much if at all.
Reduced CRP – Grape seed extract can reduce CRP and other markers of inflammation to a small extent.
Reduced appetite – The supplement can reduce appetite and overall voluntary food intake.
Antioxidant properties – Grape seed extract can reduce general oxidation. The difference is small but reliable.

Possible side effects

The side effects below are dose-dependent. The risk for them increases (often linearly but sometimes exponentially) as you increase the dose. Some of the side effects only apply to very high doses.

Reduced appetite – While this is certainly a benefit for some people, it can also be viewed as a negative for those who are trying to gain weight and are already eating less than they want to.
Initial adverse reaction – When you start taking grape seed extract, things can get worse before they get better. This supplement can temporarily worsen some aspects of your health and even make you sick for a few days after you start taking it. That can be unpleasant, but it is usually a sign that the supplement is working and creating a hormetic response that allows the body to adapt and become more resilient in the long term.
Allergic reaction – Some people are allergic to grape seeds and may experience an allergic reaction after they start taking them. Unlike the “initial adverse reaction,” allergic reactions typically don’t disappear until one stops taking the supplement.
Nausea – This side effect is most common when people take the supplement on an empty stomach.
Diarrhea – You can usually prevent diarrhea or stomach discomfort by taking this supplement with a meal.
Toxicity – As an adaptogen, grape seed extract acts as a mild stressor on the body. That is usually a great thing as it allows your body to adapt to specific forms of stress and become more resilient. However, stressing the body too much can be counter-productive and cause multiple side effects, including toxicity. While acute toxicity is extremely rare, taking high amounts of this supplement could lead to chronic toxicity and cause health problems over time. To prevent chronic toxicity or the buildup of tolerance, staying below 600 mg of grape seed extract in a day is best unless you have a great reason to take more.
Contamination – If growing or storing conditions are not adequately controlled, grape seeds can be contaminated with bacteria, molds, and other potentially harmful microorganisms. Some growers also use pesticides and herbicides that can be unsafe. Another issue is that herbal supplements can get contaminated with other supplements and chemicals during the manufacturing process. Choose the brand you get herbs and herbal supplements from wisely. It is often best to use websites like Amazon, where thousands of users have reviewed and rated the products. You are less likely to buy something of lower quality there.

Who should not take grape seed extract?

You should probably avoid taking grape seed extract if you:

are allergic to grapes or grape seeds
experience a severe adverse reaction after taking the supplement (though a mild adverse reaction is usually a great thing as it is a sign that the supplement is working and causing a hormetic response that allows the body to adapt and become more resilient)
are pregnant or breastfeeding (while it can be safe to take this adaptogen during pregnancy or breastfeeding, it acts as a mild stressor and can put some unnecessary risk to the child)

Who will benefit the most?

You should consider taking the supplement if you:

wish to increase blood flow
have a high budget for supplements and are willing to experiment with a variety of them (assuming you don’t fall into any of the categories that should avoid this supplement, grape seed extract appears safe and is unlikely to do more harm than good for most people)

How much grape seed extract should you take?

Because grape seed extract has adaptogenic properties, it acts as a mild hormetic stressor on the body, which allows your body to adapt and become more resilient to certain kinds of stressors in the long term.

A higher dose does not necessarily lead to more pronounced benefits. Instead, there appears to be an inverted U-shaped dose-response pattern. In other words, you want to find a sweet-spot dose that allows you to get the benefits of grape seed extract without putting too much pressure on the body or quickly causing the body to develop tolerance to the supplement.

The sweet-spot dose typically ranges anywhere between 150-600 mg of grape seed extract daily.

The higher end of this range usually provides slightly more benefits in the short term. If you plan to take this supplement for a longer time (multiple months or years), the lower end is probably a better way to go since you would develop tolerance faster if you were to take higher doses.

Additionally, very high doses can put too much pressure on your system and cause health problems if you take the supplement for a prolonged period.

While the seeds could theoretically cause acute toxicity, you’d need to take an extremely high dose that would be way beyond what even the most potent supplements contain.

Like most other adaptogens, it is best to cycle grape seed extract and take about two days off weekly to reset your tolerance. That will allow you to keep getting the benefits in the long term.

Keep in mind that the effects of this supplement are cumulative. Therefore, you must take it for at least 2-4 weeks to notice most of the benefits. But again, cycling the supplement and not taking it at least twice a week is necessary to prevent tolerance in the long term.

Best time to take grape seed extract

You can take this supplement with or without food. Each of these options has its benefits. The main bioactive compounds in grape seeds should absorb well either way.

If you experience nausea or stomach discomfort when you take this supplement, taking it with food should prevent these unpleasant effects or at least make them less intense.

If you take this supplement on an empty stomach, the short-term effects will kick in faster, and they will be more pronounced but will not last as long.

Whether you take this supplement in the morning or the evening typically does not make much difference. Both options are fine so feel free to experiment.

Interactions

Jiaogulan
This combination appears highly synergistic in improving central insulin resistance.

Where to buy grape seed extract?

In most countries, Amazon is the best option for ordering grape seed extract and other plant-derived supplements. They offer some very affordable products backed by many positive reviews. Also, you can choose from a wide range of brands without having to search through other markets on the internet.

Some brands display the dosage per serving instead of per pill or capsule. Therefore, you may accidentally buy something less potent than you intended. Do not fall for this marketing trick.

FAQ

As with most other plant-derived supplements, it is best to cycle grape seed extract and take a break from it for about two days per week to reset your tolerance back to baseline. That will keep your body sensitive to the supplement and allow you to keep getting the benefits in the long term.

All of these options are fine. The two most important things to consider are the price and dosing. Powders are almost always the cheapest form. However, you may need a highly accurate scale to dose them correctly (preferably 0.001g). You can get one for as little as $20 from Amazon. Dosing the powders also takes time which can add up over months or years. The disadvantage of capsules is that they are often made of bovine gelatine, which rarely comes from ethical sources.

Yes, you can. This supplement should not impact your sleep in any negative way. Whether you take it in the morning or the evening typically doesn’t make much difference. Both options are fine so feel free to experiment.

This supplement should not become harmful once it exceeds the expiration date, but it can lose potency over time. Keep this supplement in a cold, dark, and dry place and it should remain just as potent for many months or even years.

As an adaptogen, grape seed extract acts as a mild stressor on the body. That is usually a great thing as it allows your body to adapt to specific forms of stress and become more resilient. However, putting too much pressure on the body can be counter-productive and cause multiple side effects, including toxicity. While acute toxicity is extremely rare, taking very high amounts of this supplement could lead to chronic toxicity and cause health problems over time. High doses can also make you develop tolerance much faster than lower doses so they may be less effective in the long term.

While you could safely take higher doses, there is usually no point in taking more than 600 mg of grape seed extract daily. This amount should give you most of the benefits without meaningful side effects. Paradoxically, taking a higher dose would likely lead to fewer benefits as the body would quickly become accustomed to the supplement.

Unfortunately, there is not much information about the half-life of grape seed extract in the body. However, most of the effects of this supplement are cumulative, so they mostly happen in the long term rather than acutely. Therefore, the half-life of this supplement isn’t very relevant in practice.

The effects of this supplement are cumulative. Therefore, you must take it for at least 2-4 weeks to notice most of the benefits. But again, cycling the supplement and not taking it at least twice a week is necessary to prevent tolerance in the long term.

Yes, grape seed extract is vegan-friendly. If you buy this supplement in a capsulated form, beware that the capsules often contain animal-based gelatin. Instead, find a brand that puts its products into cellulose capsules.

No, it does not. The supplement does not interfere with fasting in any significant way.

References

Most of the information in this guide is based on scientific research that can be found and verified in the PubMed medical library. We highly encourage you to use the library to verify anything you read in this article. We excluded from consideration studies that are either confounded or have a high conflict of interest.

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