Product Overview
Big Bold Health Immune Rejuvenate®, formerly known as HTB Rejuvenate®, is a concentrated polyphenol formula built around Himalayan Tartary Buckwheat and four complementary flavonoids: quercetin, rutin, luteolin, and hesperidin. Each two-capsule serving provides 579 mg of these four polyphenols, along with HTB Activ™, 2-HOBA, D-chiro-inositol, vitamin C, calcium, and copper to support healthy immune signaling, cellular antioxidant defenses, metabolic resilience, and healthy aging.*
Best For
- Adults looking for concentrated and diverse polyphenol support*
- Supporting healthy immune-cell signaling and immune resilience*
- Supporting cellular antioxidant defenses and oxidative stress balance*
- Supporting metabolic and immunometabolic health*
- Adults interested in Himalayan Tartary Buckwheat and healthy-aging nutrition*
- Complementing a colorful, phytonutrient-rich diet*
A Concentrated Polyphenol Formula
Polyphenol supplements are often built around one familiar compound. Immune Rejuvenate® takes a broader approach.
The formula combines 330 mg of quercetin with 83 mg each of rutin, luteolin, and hesperidin. Together, those four flavonoids provide 579 mg per two-capsule serving.
They are paired with Himalayan Tartary Buckwheat, a plant naturally distinguished by its unusually diverse phytochemical profile, along with 2-HOBA and D-chiro-inositol.
The result is more targeted than simply eating buckwheat and more diverse than taking a stand-alone quercetin capsule.
What Each Two-Capsule Serving Provides
- Quercetin: 330 mg
- Himalayan Tartary Buckwheat: 95 mg
- Luteolin: 83 mg
- Hesperidin: 83 mg
- Rutin: 83 mg
- D-chiro-inositol: 35 mg
- 2-HOBA: 13 mg
- Vitamin C: 20 mg
- Calcium: 30 mg
- Copper: 0.3 mg
Serving size: 2 capsules
Container size may vary by product configuration. Always refer to the current Supplement Facts panel on the bottle you receive.
HTB Activ™ and Himalayan Tartary Buckwheat
Himalayan Tartary Buckwheat, Fagopyrum tataricum, is an ancient pseudocereal with a phytochemical profile very different from conventional wheat or common modern grains.
Big Bold Health developed HTB Activ™ from Himalayan Tartary Buckwheat grown with U.S. farming partners and sprouted to enhance its nutritional potential. The plant naturally contains a wide spectrum of polyphenols and related phytonutrients.
Immune Rejuvenate® uses that broader food-derived chemistry as the foundation for a more concentrated formula.
Quercetin
Quercetin is one of the best studied dietary flavonoids and is naturally found in onions, apples, berries, capers, and many other plant foods.
It participates in cellular antioxidant systems and helps support normal immune signaling and a balanced inflammatory response.* Immune Rejuvenate® provides 330 mg per serving, making quercetin the largest separately quantified polyphenol in the formula.
Rutin
Rutin is closely associated with Tartary buckwheat and is one of the plant's signature flavonoids.
Its chemistry is related to quercetin, but its absorption and metabolism differ. Intestinal bacteria participate in breaking rutin down, creating another connection between dietary polyphenols and the microbiome.
Using both rutin and quercetin provides a broader flavonoid exposure than either compound alone.
Luteolin
Luteolin occurs naturally in foods and herbs including celery, parsley, peppers, thyme, and chamomile.
It has attracted considerable research interest for its interaction with cellular signaling, oxidative stress pathways, and immune physiology.* Immune Rejuvenate® provides 83 mg per serving.
Hesperidin
Hesperidin is best known as a citrus bioflavonoid, concentrated particularly in citrus peel and pith.
It complements the other flavonoids in Immune Rejuvenate® with nutritional support for antioxidant defenses, vascular health, and healthy inflammatory signaling.*
2-HOBA
Immune Rejuvenate® also provides 13 mg of 2-hydroxybenzylamine, or 2-HOBA, a naturally occurring phytochemical that has been identified in Tartary buckwheat.
2-HOBA is being studied for its ability to interact with reactive lipid-derived compounds produced during oxidative stress. Its inclusion gives the formula another layer beyond conventional flavonoid supplementation.
D-Chiro-Inositol
D-chiro-inositol acts as a cellular signaling molecule and participates in pathways involved in metabolic communication and insulin signaling.
Its inclusion is particularly relevant to the emerging field of immunometabolism, where researchers are studying how metabolic function and immune-cell behavior influence one another.
Polyphenols and Immunometabolism
The immune system does not operate independently from metabolism. Immune cells need energy, respond to nutrient availability, communicate with the microbiome, and change their behavior in response to metabolic and inflammatory signals.
Polyphenols are interesting in this setting because they interact with many of those pathways rather than functioning only as direct antioxidants.
That broader biology is explored in our guide to Polyphenols, Immunometabolism, and Longevity Medicine.
Human Research on HTB Rejuvenate
Immune Rejuvenate® also has an unusual advantage for a supplement in this category: its product lineage has been evaluated in a published human clinical study.
A 2024 study published in Frontiers in Nutrition enrolled 50 generally healthy adults and examined epigenetic and immune-related measures before and after 90 days of supplementation with an HTB Rejuvenate polyphenol formula.
The investigators reported changes in several DNA-methylation measures, immune-cell estimates, and gene pathways related to immunity and aging. Among participants who began the study with higher PCPhenoAge acceleration, the researchers observed a statistically significant reduction in that measure after the intervention.
Genome-wide analysis also identified changes in methylation patterns associated with pathways involving ceramide kinase, the COP9 signalosome, cellular differentiation, and other biologic processes.
These are interesting findings because human intervention data on complex polyphenol formulas are still relatively uncommon.
The study was exploratory rather than definitive. It was a small, single-arm trial without a placebo group, and some of the strongest aging-clock findings came from subgroup analyses. The research formulation was also taken at four capsules daily and was not identical in every ingredient amount to the current two-capsule serving.
For that reason, the study supports continued interest in the formula and its polyphenol strategy, but it should not be interpreted as proof that Immune Rejuvenate® prevents disease or reverses human aging.
Read the published HTB Rejuvenate study
How to Use Immune Rejuvenate®
Take 2 capsules daily with water, or use as directed by your healthcare professional.
Consistency makes more sense than treating polyphenols as an occasional rescue strategy. Immune Rejuvenate® can be used alongside a plant-rich Mediterranean-style diet, adequate protein, regular exercise, restorative sleep, and attention to metabolic health.
Dietary Features
- Vegetarian
- Gluten-free
- Non-GMO
- HTB Activ™ produced from Himalayan Tartary Buckwheat grown with U.S. farming partners
Buckwheat is botanically unrelated to wheat despite its name. Anyone with a known buckwheat allergy should avoid products containing Himalayan Tartary Buckwheat.
The HormoneSynergy® Perspective
What we like about Immune Rejuvenate® is not one headline ingredient. It is the combination.
Quercetin provides the largest concentrated dose, while rutin, luteolin, and hesperidin broaden the flavonoid profile. Himalayan Tartary Buckwheat adds a food-derived phytochemical matrix. 2-HOBA and D-chiro-inositol extend the formula into additional areas of cellular and metabolic signaling.
For someone already eating well but looking for more concentrated polyphenol support, Immune Rejuvenate® is one of the more thoughtfully constructed formulas in this category.*
It also fits comfortably with the way we think about longevity nutrition: not as a search for one magic antioxidant, but as an effort to expose the body to a wider range of useful nutritional signals.
Related HormoneSynergy® Resources
Frequently Asked Questions
Is HTB Rejuvenate® now called Immune Rejuvenate®?
Yes. Big Bold Health now markets the capsule formula as Immune Rejuvenate®. It was previously sold as HTB Rejuvenate®, so both names may still appear in older articles, research, packaging, and product references.
How many polyphenols are in each serving?
Each two-capsule serving provides 579 mg from four separately listed polyphenols: 330 mg quercetin plus 83 mg each of rutin, luteolin, and hesperidin.
Does Immune Rejuvenate® contain Himalayan Tartary Buckwheat?
Yes. Each current two-capsule serving provides 95 mg of Himalayan Tartary Buckwheat as part of a formula inspired by the naturally diverse polyphenol profile of Tartary buckwheat.
What is 2-HOBA?
2-HOBA, or 2-hydroxybenzylamine, is a naturally occurring phytochemical identified in Tartary buckwheat and studied for its interaction with reactive compounds generated during oxidative stress. The current formula provides 13 mg per serving.
What does Immune Rejuvenate® support?
The formula is designed to support healthy immune signaling, cellular antioxidant defenses, balanced inflammatory pathways, metabolic resilience, and healthy-aging physiology.*
Has HTB Rejuvenate® been studied in humans?
Yes. A 2024 published pilot study evaluated a prior HTB Rejuvenate formulation for 90 days and reported changes in several epigenetic, immune-cell, and gene-pathway measures. The trial was small and uncontrolled, and the study dose and some ingredient amounts differed from the current product, so the findings are best viewed as promising early human research rather than proof of a clinical outcome.
How should I take Immune Rejuvenate®?
The current manufacturer direction is 2 capsules daily with water, or as directed by your healthcare professional.
Is Immune Rejuvenate® vegetarian and gluten-free?
Yes. The current product is identified as vegetarian, gluten-free, and non-GMO.
If pregnant or nursing, taking prescription medication, preparing for surgery, or managing a significant medical condition, discuss supplement use with your healthcare professional. Individuals with a known buckwheat allergy should not use this product.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.