Most comprehensive anti-oxidant
5 out of 5 star rating. 
Formulated as the best antioxidant
Validated by research
20x
stronger than vitamin C
50x
stronger than vitamin E
95%
intestinal nutrient delivery for max absorption
Oligomeric proanthocyanadins (OPCs) are bioflavonoids (complex organic compounds) found in fruits, vegetables and certain tree barks that provide exceptional nutritional benefits to the human body.
The Super Antioxidant in OPC-3, Pycnogenol®‡
Isotonix OPC-3 contains the only isotonic form of Pycnogenol® in the world. Pycnogenol® is a natural plant extract from the bark of the French maritime pine tree and the most clinically researched and potent bioflavonoid.
Product Classification
Gluten-Free
No Detectable GMO
Isotonic
Vegan
Good Manufacturing Practices
Dairy Free
Directions for Use
Pour 1 small capful (3.3 g) of powder into a cup.
Add water 2 fl. oz/60 mL of water for each capful and stir.
Enjoy once a day. For maximum absorption take on an empty stomach.
Key Ingredients & Benefits
Grape Seed Extract*
Maintains healthy cholesterol levels
Red Wine Extract*
Powerful antioxidant
Bilberry Extract*
Powerful antioxidant
Supports healthy vision
Maintains healthy circulation
Citrus Extract (Bioflavaniods)*
Promotes cardiovascular health
Maintains healthy circulation
Pycnogenol®‡, Pine Bark Extract*
Supports the normal dilation of blood vessels
Provides complete antioxidant protection
Combats free radicals
Supports a healthy complexion
Promotes healthy sperm quality
World's Most Powerful Antioxidant
Outperforming any conventional antioxidant on the market, discover this ultimate supplement designed to supercharge health and longevity!
Isotonix Delivery System
:05 minutes
Isotonix Liquid Vitamins
- Formulated to survive digestion.
- Delivers concentrated nutrients to the site of absorption.
- Contains no fillers or binders.
- No artificial color or flavors.
:40 minutes
Standard Vitamin Tablet
- Contains lab-created coatings and lubricants.
- Often contains artificial colors, nutrients and flavors.
- Limited absorption of nutrient utilization.
Frequently Asked Questions
What makes Isotonix OPC-3 special?
Isotonix OPC-3 contains bioflavonoids, plant compounds that support cardiovascular health, healthy circulation and skin, joint and tissue integrity; it uses a unique Isotonix delivery system for fast, effective absorption and includes scientifically proven antioxidants to fight free radicals, making it one of the most powerful products available.
How quickly does Isotonix OPC-3 work?
Thanks to its liquid, isotonic form, Isotonix OPC-3 is absorbed quickly by the small intestine, entering the bloodstream within minutes; this rapid absorption allows the body to benefit almost immediately.
Why should everyone take Isotonix OPC-3?
Free radicals cause oxidative stress, which contributes to aging, circulation and heart and immune health. OPCs are powerful antioxidants — with more staying power than vitamins C and E — that help neutralize free radicals. Taking OPC-3 daily is essential for combating free radical damage and promoting health.
Why should healthy or athletic people use Isotonix OPC-3?
Even athletes experience free radical damage from increased oxygen use during exercise, which can affect muscle performance and endurance. Studies show OPCs promote endurance, reduce mild muscle cramps and support healthy blood flow, helping muscles recover and perform.
Does OPC-3 benefit people who menstruate?
Yes, studies show OPCs can help mensural cramps.
What is Pycnogenol®?
Pycnogenol® is a patented extract from French maritime pine bark, supported by over 120 clinical studies; it acts as a powerful antioxidant, helping maintain healthy circulation, blood pressure and blood vessel function by promoting nitric oxide production.
Research Scope on OPC-3
558+
Studies on Pycnogenol® and Human Health
100
The number of active compounds found in Red Wine Extract
3
Independent studies for Isotonix OPC-3®
4x
The bioavailability of Isotonix OPC-3® compared to a tablet form
*These statements have not been evaluated by the Food and Drug Administration. This product(s) is not intended to diagnose, treat, cure or prevent any disease.
‡As Pycnogenol®. Pycnogenol is a registered trademark of Horphag Research Ltd. Use of this product may be protected by one or more U.S. patents and other international patents.
Reviews
Break down of ratings: (305) 5 star ratings. (28) 4 star ratings. (14) 3 star ratings. (4) 2 star ratings. (19) 1 star ratings.
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Nothing beats OPC-3. It should be the4 baseline antioxidant in any formula but this product is the only truly isotonic-capable one that I've seen on the market.
Absolutely Fantastic
5 out of 5 star rating.
Love OPC been taking it for over 25 years.. Of all the supplements I've taken and tried through the years OPC has been the best and I will continue to take it everyday.
Response from Customer Service on 05/28/2026
Thank you for your wonderful review! It’s awesome to know that you have been part of the Isotonix family for over 25 years and still hold the same love and appreciation for Isotonix OPC-3® for Adults & Children Ages 4+ since the beginning. Your continued loyalty and positive experience truly mean a lot to us. Thank you for making Isotonix OPC-3® a trusted part of your daily routine and for being such a valued customer!
OPC3 is an all time lifer product
5 out of 5 star rating.
For over 28 years OPC3 has been our non negotiable supplement. It is the world's most powerful antioxident and has assisted in blessing me with good health.
Thank you Market America!
Response from Customer Service on 05/28/2026
Thank you so much for your wonderful review! It’s inspiring to hear that you’ve made Isotonix OPC-3® for Adults & Children Ages 4+ a non-negotiable part of your routine for over 28 years. Your ongoing loyalty and appreciation mean a great deal to us. Thank you for your kind words and for being a valued part of the Isotonix family, your support truly motivates us every day!
OPC-3
5 out of 5 star rating.
Been using this product for over a decade and I know it has been very beneficial to my overall health, top notch quality and service on all the products from Shop. com, thanks again...
Response from Customer Service on 05/12/2026
Thank you so much for your loyal support and wonderful feedback on Isotonix OPC-3®! We’re delighted to hear you’ve been enjoying the product for over a decade and that you’ve had a great experience with our quality and service. Your trust and satisfaction mean a great deal to us. Thank you for choosing Shop.com and Isotonix® as part of your wellness journey!
25 years and growing!
5 out of 5 star rating.
I have taken this product for 25 years plus and I would rather leave my cell phone at home than to go without this product. Thank me later!
Response from Customer Service on 05/04/2026
Thank you so much for sharing your incredible dedication to Isotonix OPC-3® over the past 25 years! We're honored that you consider it an essential part of your daily routine and appreciate your passion for the product. Your loyalty and enthusiasm mean a lot to us. Thank you for being such a valued member of our community!
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