The Immunity Duo
Advanced gut support plus highly absorbable quercetin for year-round immune support
Helps Support
Digestion
Wellbeing
Immunity
Gut and immune support, working together
Around 70-80% of your immune system is in the gut. The Immunity Duo combines Biome Shield+ for targeted gut and microbiome support with Immunity+ Advanced for normal immune function – complementary support in one simple daily routine.
500mg EpiCor® postbiotic
Biome Shield+ provides 500mg EpiCor®, a whole yeast fermentate and postbiotic designed to support a healthy gut and microbiome. Vitamin B2 helps maintain normal mucous membranes, including the protective lining of your gut, to defend against infection.
Highly absorbable Quercefit® quercetin
Immunity+ Advanced provides 250mg Quercefit®, a phospholipid form of quercetin shown in human research to be up to 20x more bioavailable than standard quercetin. It also provides vitamins C and D for normal immune function.
Support through the seasons
The ingredients have been studied for more than everyday nutritional support. EpiCor® has been shown to reduce the duration of cold and flu-like symptoms by 17%, while Quercefit® has been shown to reduce hay fever symptoms in human research.
Backed by human research
Together, EpiCor® and Quercefit® are supported by 18 human clinical studies, giving both sides of the duo a substantial body of human evidence.
Advanced Multi+ Ingredients:
Aquamin® Magnesium Citrate, Capsule Shell (Hydroxypropyl Methylcellulose), AstaPure® Whole Algae Powder Astaxanthin (Haematococcus pluvialis), UbiqSome® CoQ10-Phospholipid Complex (Co-EnzymeQ10, Sunflower Lecithin), Calcium Ascorbate, PureSea® Seaweed Extract, LactoSpore® (Bacillus coagulans MTCC 5856), Vitamin K2 MenaQ7® (MK-7), Iron Bisglycinate, Anticaking Agent (Bamboo Extract), Natural D-Alpha Tocopherol Acetate, Nicotinamide, Zinc Bisglycinate, Affron® (Saffron (Crocus sativus L.) Stigmas Extract [Std to 3.5% Lepticrosalides® by HPLC]), Selenomethionine, Vita-algae D™ Powder (Cholecalciferol), Calcium Pantothenate, Retinol Acetate, Pyridoxal-5-Phosphate, Riboflavin-5-Phosphate, Copper Citrate, Thiamine HCl, Chromium Picolinate, Quatrefolic® ((6S)-5-Methyltetrahydrofolic acid, Glucosamine Salt), D-Biotin, Methylcobalamin.
Affron® is a registered trademark of Pharmactive Biotech Product, SLU. Aquamin® is a trademark of Marigot Ltd. LactoSpore® is a trademark of Sabinsa. MenaQ7® is a registered trademark of Lessaffre et Compagnie, France. PureSea® is a registered trademark of Seaweed & Co. Quatrefolic® is a registered trademark of Gnosis SpA. UbiqSome® is a registered trademark owned by Indena S.p.A., Italy. Vita-algae D™ is a trademark of Cambridge Commodities Ltd.
Immunity+ Advanced Ingredients:
QuerceFit® Quercetin Phospholipid Complex (Quercetin from Japanese Pagoda Tree (Sophora japonica) Flower Extract, Sunflower Lecithin, Maltodextrin, Silicon Dioxide), Bulking Agent (Rice Flour), Capsule Shell (Hydropropyl Methylcellulose), Ascorbic Acid (Vitamin C), Lichen Cholecalciferol (Vitamin D3).
QuerceFit® is a registered trademark of Indena SpA, Italy
Food supplements should not be used as a substitute for a varied and balanced diet or a healthy lifestyle. If you are pregnant, breastfeeding, taking any medication or are under medical supervision, please consult a doctor or pharmacist before taking supplements. If you suffer any adverse reaction whilst using a supplement, discontinue use and consult your doctor. Keep out of reach of children. Allergens are highlighted in bold within the ingredients list.
Why these two work well together
Around 70-80% of your immune system is associated with your gut. The Immunity Duo covers both: Biome Shield+ supports your gut with a postbiotic and vitamin B2, while Immunity+ Advanced provides the vitamins C and D that support normal immune function, plus highly absorbable quercetin, valued for its antioxidant, anti-inflammatory and longer-term immune-supporting properties.
The duo’s branded ingredients are backed by 18 human studies, including EpiCor® – shown to reduce the duration of cold and flu-like symptoms by 17%, and Quercefit® – shown to reduce hay fever symptoms. Taken together – one capsule of each a day – they’re a simple way to support your immunity throughout the seasons.
Immunity+ Advanced – clinically studied quercetin
The hero ingredient in Immunity+ Advanced is quercetin, a plant flavonoid with antioxidant and immune-supporting properties naturally found in foods such as apples, onions and berries. Standard quercetin is difficult for the body to absorb; Quercefit® combines quercetin with sunflower lecithin to form a phospholipid complex that your body can easily use.
- 250mg Quercefit®, a clinically studied phospholipid formulation of quercetin
- Up to 20x more absorbable than standard quercetin, shown in a clinical human study*
- Vitamins C & D3 for the normal function of the immune system
- Quercefit® was shown to reduce hay fever symptoms in a human study**
- Quercefit® is supported by more than 10 human clinical studies
*Riva, A. et al., Eur J Drug Metab Pharmacokinet, 2019
**Yamada, S. et al., Eur Rev Med Pharmacol Sci, 2022
Biome Shield+ – postbiotic support for your gut
Biome Shield+ contains EpiCor®, a whole postbiotic yeast fermentate with beneficial compounds produced by fermentation. Like eating fermented foods, it supports a healthy gut and microbiome, and feeds your immune defences.
Added vitamin B2 contributes to the health of normal mucous membranes, including the protective surfaces lining your nose, mouth and gut – important for blocking harmful bacteria and viruses from entering the body.
- Provides bioactive compounds that can positively influence your immune system
- Shown to reduce the duration of cold and flu-like symptoms by 17%*
- Vitamin B2 helps protect immune cells from oxidative stress
- Backed by 8 human clinical studies
*Moyad, M. A., et al., Urol Nurs, 2008
The quercetin problem – and how Quercefit® solves it
The form of quercetin you take matters. Swallow a large dose of standard quercetin powder and very little of it will reach your bloodstream and get to work
Quercefit® tackles this absorption problem by combining quercetin from the Japanese pagoda tree with sunflower lecithin to form a phospholipid complex. This passes through your gut wall far more readily.
In a human clinical study, Quercefit® was shown to be up to 20x more bioavailable than standard quercetin (Riva, A et al., 2019). Each capsule of Immunity+ Advanced delivers 250mg, equivalent to 2,500mg of ordinary quercetin powder.
“We understand more and more how closely gut and immunity are connected. This duo supports both, combining EpiCor® postbiotic with Quercefit® quercetin in a form shown to be up to 20 times more bioavailable.”
Ingredient highlights
Quercetin is a flavonoid found in onions, apples and berries, highly valued for its antioxidant, anti-inflammatory and immune-supporting properties. The problem is absorption: in its standard form, very little quercetin will reach your bloodstream, however much you take.
Quercefit® mixes quercetin from the Japanese Pagoda tree with sunflower lecithin, forming a phospholipid complex that reaches the gut far more readily and is up to 20 times more absorbable than standard quercetin, as shown in a human clinical study (Riva et al., 2019).
Each capsule of Immunity+ Advanced provides 250mg Quercefit®, the same daily amount used in human research showing a reduction in hay fever symptoms (Yamada et al., 2022).
EpiCor® is the postbiotic at the heart of Biome Shield+ – a whole yeast fermentate made by fermenting Saccharomyces cerevisiae (baker's yeast) and drying the entire ferment to preserve its complete fingerprint of metabolites. Rather than isolating a single compound, EpiCor® keeps the whole postbiotic profile intact, which is why it's often described as working like a multivitamin for your gut, providing bioactive compounds that can positively influence your immune system.
EpiCor® is one of the most scientifically researched postbiotic ingredients available, shown to reduce the duration of cold and flu-like symptoms by 17% in a human study (Moyad, M. A., et al., Urol Nurs, 2008).
Vitamin C (80mg, 100% NRV) contributes to the normal function of the immune system and to the protection of cells from oxidative stress. Vitamin D (5µg, 100% NRV) contributes to the normal function of the immune system and to the maintenance of normal bones and muscle function – D3 sourced from lichen to be suitable for vegans. Together, vitamins C and D are the immune foundation that the highly absorbable quercetin complements.
Quercetin is a flavonoid found in onions, apples and berries, highly valued for its antioxidant, anti-inflammatory and immune-supporting properties. The problem is absorption: in its standard form, very little quercetin will reach your bloodstream, however much you take.
Quercefit® mixes quercetin from the Japanese Pagoda tree with sunflower lecithin, forming a phospholipid complex that reaches the gut far more readily and is up to 20 times more absorbable than standard quercetin, as shown in a human clinical study (Riva et al., 2019).
Each capsule of Immunity+ Advanced provides 250mg Quercefit®, the same daily amount used in human research showing a reduction in hay fever symptoms (Yamada et al., 2022).
EpiCor® is the postbiotic at the heart of Biome Shield+ – a whole yeast fermentate made by fermenting Saccharomyces cerevisiae (baker's yeast) and drying the entire ferment to preserve its complete fingerprint of metabolites. Rather than isolating a single compound, EpiCor® keeps the whole postbiotic profile intact, which is why it's often described as working like a multivitamin for your gut, providing bioactive compounds that can positively influence your immune system.
EpiCor® is one of the most scientifically researched postbiotic ingredients available, shown to reduce the duration of cold and flu-like symptoms by 17% in a human study (Moyad, M. A., et al., Urol Nurs, 2008).
Vitamin C (80mg, 100% NRV) contributes to the normal function of the immune system and to the protection of cells from oxidative stress. Vitamin D (5µg, 100% NRV) contributes to the normal function of the immune system and to the maintenance of normal bones and muscle function – D3 sourced from lichen to be suitable for vegans. Together, vitamins C and D are the immune foundation that the highly absorbable quercetin complements.
Trusted by thousands
Aine m.
It does prevent you from getting a nasty cold in winter.
Biome Shield + is a wonderful Vitamin everyone should take it all year round it does prevent you from getting a nasty cold in winter.
Lee F.
I haven't had a cold or any other respiratory problems since
It's really difficult to know whether a health supplement is working. However, since I haven't had a cold or any other respiratory problems since I have been taking it leads me to believe that it is doing me good.
Sandra W.
It seems to be holding the 'sniffles' at bay
I have only been taking this product for a month but, so far, it seems to be holding the 'sniffles' at bay
FAQs
What is in the Immunity Duo?
The Immunity Duo pairs two daily supplements: Biome Shield+, a postbiotic for gut support (EpiCor® with vitamin B2 for your gut lining), and Immunity+ Advanced, which combines highly absorbable Quercefit® quercetin with vitamins C and D for normal immune function. You take one capsule of each per day. Bought together as the duo, they work out more cost-effective than buying each separately.
How do the two products work together?
They support two closely connected areas of health. Biome Shield+ looks after your gut - using EpiCor® postbiotic and vitamin B2, which supports the maintenance of your normal gut lining. Immunity+ Advanced looks after your immune system – vitamins C and D contribute to its normal function, alongside highly absorbable quercetin. Because the gut and the immune system are closely linked, supporting both together makes sense as part of a healthy daily routine.
What is a postbiotic, and what is EpiCor®?
A postbiotic is made up of the beneficial compounds produced by fermentation, rather than live bacteria (probiotics) or the fibres that feed them (prebiotics). EpiCor® is the postbiotic in Biome Shield+: a whole yeast fermentate (from Saccharomyces cerevisiae) dried to preserve its unique fingerprint of metabolites, and one of the most researched postbiotic ingredients available. Biome Shield+ provides 500mg of EpiCor® per daily capsule.
Why is the quercetin "20x more absorbable"?
Standard quercetin is poorly absorbed by the body. Immunity+ Advanced uses Quercefit®, a quercetin phospholipid complex that combines quercetin with sunflower lecithin so it passes more easily into the bloodstream. In a human clinical study, Quercefit® was shown to be up to 20 times more absorbable than standard quercetin (Riva A. et al., Eur J Drug Metab Pharmacokinet, 2019) – so each capsule delivers the equivalent of 5,000mg of standard quercetin powder.
How and when do I take the Immunity Duo?
Take one capsule of Biome Shield+ and one capsule of Immunity+ Advanced each day, morning or evening, with or without food. Neither contains stimulants, and both are designed for consistent daily use. Gut and immune support work best maintained steadily over time, so the duo is made to be an everyday, year-round routine.
Is the duo suitable for vegans?
Yes. Both products are suitable for vegans and vegetarians. Biome Shield+ uses EpiCor® (from yeast fermentation) in a plant-based HPMC capsule, and Immunity+ Advanced uses lichen-sourced vitamin D and plant-derived quercetin. Both are gluten-free and lactose-free.
How long before I notice anything?
Immune support is not something you notice from day to day, but you may notice over the months what doesn’t happen. Depending on your starting levels, it can take weeks or months of consistent daily intake to reach optimal levels of nutrients like vitamin D. We'd suggest taking the duo for at least three months before forming a view.
Was Immunity+ Advanced called something else?
Yes – it was previously Quercetin+. Same active ingredient, same Quercefit® quercetin, renamed to reflect that it also provides vitamins C and D. If you took Quercetin+ before, this is the same product.
When will I feel the benefits?
Building daily support
From day one, the duo begins providing complementary support for your gut and immune system. Biome Shield+ supplies 500mg EpiCor® postbiotic plus vitamin B2 to support the gut lining, while Immunity+ Advanced provides vitamins C and D for normal immune function alongside highly bioavailable Quercefit® quercetin. The first month is mainly about consistency and, if your vitamin D status is low, beginning to restore nutritional levels.
Supporting resilience
By the second month, the duo has become a regular part of your routine. Consistent intake matters because gut and immune support are better maintained steadily than taken only when you feel run down. EpiCor® and Quercefit® are both backed by human clinical research, including studies showing shorter cold and flu-like symptoms with EpiCor® and reduced hay fever symptoms with Quercefit®.
When will I feel the benefits?
Ready for the seasons ahead
Immune support is often about what you don’t notice. After three months of regular use, you’ve established a consistent routine supporting both the gut and immune system, while allowing time for nutrients such as vitamin D to build towards healthy levels. The Immunity Duo is designed for ongoing, year-round use, helping you maintain that foundation through changing seasons rather than waiting until you feel under the weather.
Trusted by experts
Dr Max Gowland
Chief Scientific Officer
Max's passion is to help the over 50s stay healthy and stay active. As Chief Scientific Officer, Max works with the team to develop innovative products and is a regular presenter on QVC TV, helping to demystify supplements, health and nutrition.
Dr Miriam Ferrer
Head of Product Development
After her PhD, Miriam spent three years at the Medical Research Council Laboratory of Molecular Biology in Cambridge, before pivoting to supplement development. Her experience helps her to identify high-quality ingredients backed by rigorous research.
Dr Aidan Goggins
Nutritionist and author
Aidan is one of Europe's most influential nutrition experts and author of the award-winning book The Health Delusion and the international bestseller The Sirtfood Diet. He’s passionate about combining medicine with nutrition for better health outcomes.
Mr Peter Kirkpatrick
Medical advisor
Peter is a leading expert on strokes and arterial and vascular disease affecting the brain, and has published more than 200 studies. He is also president of the Cambridgeshire branch of Headway.
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Explore The Immunity Duo and more in our Knowledge Centre
What is Co-enzyme Q10 (CoQ10)?
Co-enzyme Q10 or CoQ10 is also known as 'ubiquinone', is a fat-soluble substance that is similar to a vitamin. Its name derives from “ubiquitous quinone”, as this molecule is found in most of the cell membranes of the body.
What is quercetin?
Quercetin is a natural plant compound with immune-supporting properties and rich in antioxidants. Found in foods like onions and apples, it's also increasingly popular as a supplement.
The story of EpiCor®
A surprising discovery on a dairy farm over 100 years ago led to EpiCor® – a unique fermented ingredient now shown to support gut and immune health in humans.
Reviews
The views expressed below are the opinions of customers who have purchased this product. We do not endorse these views, nor should they be regarded as health claims or medical advice.
