£19.99
£19.99

Great for: immune support, reducing fatigue, skin health, bones & joints, protecting against oxidative stress


Ester-C® 1400mg is an advanced, patented formulation providing a 1000mg dose of vitamin C, proven to deliver higher amounts of vitamin C into cells, with faster absorption and superior duration of action. Though Ester-C is especially beneficial for boosting the immune system because of its unusually high uptake and duration of action in immune cells, its strong bioavailability makes it the ideal supplement to support vitamin C levels for a range of health benefits.


10x GREATER ABSORPTION

Ester-C’s unique makeup of calcium ascorbate and vitamin C metabolites boosts absorption from the gut. Subsequent uptake into immune cells, where you need vitamin C most, is 10x greater

HIGH STRENGTH 1-A DAY DOSE PLUS 24-HOUR ACTION

Fast absorption, enhanced bioavailability and superior retention offer all-day coverage in one convenient 1400mg tablet. A break line is provided for easier swallowing

SUPPORTS OPTIMAL HEALTH

Ester-C makes it simple to benefit from all of vitamin C’s scientifically proven health benefits - from protecting cells against oxidative stress, reducing fatigue, supporting iron absorption and boosting collagen formation to supporting the immune system, nervous system and healthy blood vessels

GENTLE ON THE STOMACH

Unlike ascorbic acid, this buffered, non-acidic formula does not irritate the digestive tract

CONSISTENT PRODUCT QUALITY GUARANTEED

GMP manufactured - quality standards that medicines manufacturers must meet in their production processes to ensure products are of consistent high quality

FREE FROM

Dairy, gluten, lactose, soya, yeast; suitable for vegans; halal & kosher

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Ester-C 1400mg is an advanced, patented formulation providing a 1000mg dose of vitamin C, proven to deliver higher amounts of vitamin C into cells, with faster absorption and superior duration of action. Ester-C’s absorption into immune cells is 10x greater than standard vitamin C; it's also unique in offering 24-hour nutrient coverage in one daily dose. Though Ester-C is especially beneficial for boosting the immune system because of its unusually high uptake and duration of action in immune cells, its strong bioavailability makes it the ideal supplement to support vitamin C levels for a range of health benefits. 


Vitamin C’s many roles in the body include protecting against oxidative stress caused by free radicals, increasing iron absorption, supporting the nervous system, reducing fatigue, and supporting cartilage production, as well as skin, gums and teeth and blood vessel tissue. Unlike ascorbic acid, Ester-C won’t irritate the stomach as it’s non-acidic. 

Each bottle contains 60 tablets, which is a 2-months supply at the standard dose of 1 tablet daily.

Adults: take 1 tablet daily. Children aged 8 years and over: 1/2 tablet daily (tablet provided with a break line). 


Take with food for optimal absorption. Do not exceed the recommended daily dose unless advised by a healthcare practitioner.

Ingredients: Calcium Ascorbate-Threonate (Ester-C); bulking agent: microcrystalline cellulose; anti-caking agents: magnesium stearate, silicon dioxide; coating agents: hydroxypropyl methylcellulose; glycerine.

   * % Reference Intake

This product should not be used as a substitute for a balanced diet. Pregnant or breastfeeding women should consult their doctor before taking any food supplement. Keep out of the reach of children and store in a cool, dry place away from direct sunlight.

  • Dairy
  • Gluten
  • Lactose
  • Soya
  • Wheat
  • Yeast
  • Artificial colours & flavours

Not tested on animals; non-GMO; suitable for vegetarians & vegans; halal & kosher

Customer feedback

Ester-c enhanced bioavailability.. perfect

I love this Ester-c! After stress and illness, out of nowhere I ended up struggling with so many food, supplement and environmental sensitivities. Different types of vitamin c, including ascorbic acid and liposomal did not agree with me, but this is perfect! I take 1 to 2 a day! They are large so I have to break them in half to swallow them, but that’s not a problem.

Amazon review

Great brand & products

Great product, great brand, their products are well researched & intelligently formulated. I take with iron to maximise absorption & also to manage my autoimmune disease, seems to working, certainly easier on the stomach than cheaper forms of vitamin c & hopefully more bioavailable.

Amazon review

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Vitamin C in the diet – why our needs are increasing

Vitamin C’s essential role in health is widely recognised, and perhaps best known for its crucial role in the immune system. Like all nutrients, it plays a number of roles and, since it is a water-soluble nutrient and doesn’t get stored in the body, we need to consume it daily. So why do we often benefit from supplementation when it’s widely found in fruit and vegetables? Not only are nutrient levels in our food declining (few of us eat locally and seasonally and soil nutrient content is often depleted) but many of us are not achieving the recommended minimum '5-a-day'. All the while our nutrient intake is suboptimal, we’re being exposed to increasing levels of environmental pollutants, and everyday stresses generate higher and higher levels of free radicals in the body, increasing our need for vitamin C to combat oxidative stress. The body’s requirements for this important antioxidant have never been higher.

Vitamin C in the diet – why our needs are increasing

Vitamin C’s essential role in health is widely recognised, and perhaps best known for its crucial role in the immune system. Like all nutrients, it plays a number of roles and, since it is a water-soluble nutrient and doesn’t get stored in the body, we need to consume it daily. So why do we often benefit from supplementation when it’s widely found in fruit and vegetables? Not only are nutrient levels in our food declining (few of us eat locally and seasonally and soil nutrient content is depleting) but many of us are not achieving the recommended 5-a-day. All the while our nutrient intake is suboptimal, we’re being exposed to increasing levels of environmental pollutants, and everyday stresses generate higher and higher levels of free radicals in the body, increasing our need for vitamin C to combat oxidative stress. The body’s requirements for this important antioxidant have never been higher.

Vitamin C in the diet – why our needs are increasing

Vitamin C’s essential role in health is widely recognised, and perhaps best known for its crucial role in the immune system. Like all nutrients, it plays a number of roles and, since it is a water-soluble nutrient and doesn’t get stored in the body, we need to consume it daily. So why do we often benefit from supplementation when it’s widely found in fruit and vegetables? Not only are nutrient levels in our food declining (few of us eat locally and seasonally and soil nutrient content is depleting) but many of us are not achieving the recommended 5-a-day. All the while our nutrient intake is suboptimal, we’re being exposed to increasing levels of environmental pollutants, and everyday stresses generate higher and higher levels of free radicals in the body, increasing our need for vitamin C to combat oxidative stress. The body’s requirements for this important antioxidant have never been higher.

Standard vitamin C absorption is poor with doses higher than 200mg

Vitamin C uptake is regulated according to its levels present in the blood; once vitamin C levels reach a certain amount, they do not increase further. Some forms of vitamin C are absorbed well into the bloodstream but struggle to enter white blood cells to exert health benefits, so it can be difficult to boost levels in cells unless you can optimise movement out of the bloodstream. Any excess vitamin C in the blood is flushed out of the body. This is why standard vitamin C (as ascorbic acid) is ineffective in doses greater than 200mg, unless you take several doses throughout the day to achieve the levels needed to support immune function. In order to increase cellular vitamin C levels effectively, we need to improve its absorption in the gut, which is dependent on the form of vitamin C.

Vitamin C in the diet – why our needs are increasing

Vitamin C’s essential role in health is widely recognised, and perhaps best known for its crucial role in the immune system. Like all nutrients, it plays a number of roles and, since it is a water-soluble nutrient and doesn’t get stored in the body, we need to consume it daily. So why do we often benefit from supplementation when it’s widely found in fruit and vegetables? Not only are nutrient levels in our food declining (few of us eat locally and seasonally and soil nutrient content is depleting) but many of us are not achieving the recommended 5-a-day. All the while our nutrient intake is suboptimal, we’re being exposed to increasing levels of environmental pollutants, and everyday stresses generate higher and higher levels of free radicals in the body, increasing our need for vitamin C to combat oxidative stress. The body’s requirements for this important antioxidant have never been higher.

Standard vitamin C absorption is poor with doses higher than 200mg

Vitamin C uptake is regulated according to its levels present in the blood, and once vitamin C levels reach a certain level, they do not increase further. Some forms of vitamin C are absorbed well into the bloodstream but struggle to enter white blood cells to exert health benefits, so it can be difficult to boost levels in cells unless you can optimise movement out of the bloodstream. Any excess vitamin C in the blood is flushed out of the body. This is why standard vitamin C (as ascorbic acid) is ineffective in doses greater than 200mg, unless you take several doses throughout the day to achieve the levels needed to support immune function. In order to increase cellular vitamin C levels effectively, we need to improve its absorption in the gut, which is dependent upon the form of vitamin C.

Ester-C - calcium ascorbate & vitamin C metabolites

  • Ester-C is a patented formulation combining vitamin C with calcium in a chemical-free, water-based process. This results in a pH-neutral blend of calcium ascorbate and vitamin C metabolites, mainly dehydroascorbate and calcium threonate. Dehydroascorbate is the form of vitamin C able to cross the blood-brain barrier
  •  Calcium ascorbate delivers all the standard vitamin C benefits; however, vitamin C metabolites make Ester-C unique
  •  As Ester-C contains different forms of vitamin C, it is absorbed quickly and efficiently through different pathways into the blood. This may benefit those genetically predisposed to decreased vitamin C absorption. The different forms are also absorbed optimally in different parts of the gut, which may benefit those with absorption issues
  • Vitamin C metabolites boost the uptake of vitamin C into immune cells. Ester-Cmaintains high levels of vitamin C in cells for 24 hours, making 1-a-day dosing effective

Superior absorption & 24-hour action

  • For vitamin C to perform its functions and exert its health benefits, it is essential for it to be absorbed from the bloodstream into the cells. While some vitamin C products may be reasonably well absorbed from the gut into the bloodstream, they struggle to enter cells because of the vitamin C structure. Once vitamin C levels in the blood reach a certain level, they do not increase further, no matter how much vitamin C is consumed. To increase levels in the body, there needs to be increased movement of vitamin C out of the blood into the cells, which is what the vitamin C metabolites found in Ester-C enable
  •  Ester-C is the only form of vitamin C which shows unprecedented uptake into and retention in immune cells for 24 hours. It boasts an impressive 10x greater white blood cell bioavailability than standard vitamin C

How is Ester-C better than standard vitamin C?

  • Ester-C has been studied for decades, and is better researched than all other forms of buffered vitamin C
  •  Standard vitamin C is absorbed from the gut into the bloodstream fairly well at low doses (up to 200mg), but mega-dosing on standard vitamin C will not lead to raised levels in the blood after a certain level is reached. Standard vitamin C struggles to enter the cells of the body because of its structure, so it is quickly flushed from the body
  • Large doses of standard vitamin C are acidic and can irritate the gut, especially at a high dose, causing abdominal cramps, nausea and diarrhoea. Ester-C combines vitamin C with calcium in a chemical-free, water-based process, resulting in a pH-neutral blend so it’s gentle on the stomach
  • Achieving high levels in the body with standard vitamin C doses would require dosing repeatedly throughout the day and night. Ester-C, however, can be taken as 1 tablet per day as it gets into and stays at high levels in immune cells for 24 hours

Why choose Ester-C over other forms of optimised vitamin C?

Ester-C vs slow-release vitamin C

Studies do not support significant benefits of slow-release vitamin C compared to even standard vitamin C.  

Ester-C vs liposomal vitamin C

Ester C is superior to liposomal vitamin C in terms of its uptake and retention in immune cells. Although liposomal vitamin C does raise levels of vitamin C in the bloodstream effectively, it is the absorption of vitamin C into cells which is the crucial factor for it to perform its function.

Our Ester-C vs other Ester-C products

Some other Ester-C products use a bovine capsule shell. Our Ester-C tablets contain no animal products.

Ester-C® - calcium ascorbate & vitamin C metabolites

  • Ester-C® is a patented formulation combining vitamin C with calcium in a chemical-free, water-based process. This results in a pH-neutral blend of calcium ascorbate and vitamin C metabolites, mainly dehydroascorbate and calcium threonate. Dehydroascorbate is the form of vitamin C able to cross the blood-brain barrier. 
  •  Calcium ascorbate delivers all the standard vitamin C benefits; however, vitamin C metabolites make Ester-C unique. 
  •  As Ester-C® contains different forms of vitamin C, it is absorbed quickly and efficiently through different pathways into the blood. This may benefit those genetically predisposed to decreased vitamin C absorption. The different forms are also absorbed optimally in different parts of the gut, which may benefit those with absorption issues. 
  • Vitamin C metabolites boost the uptake of vitamin C into immune cells. Ester-C maintains high levels of vitamin C in cells for 24 hours, making 1-a-day dosing effective.

Superior absorption & 24-hour action

  • For vitamin C to perform its functions and exert its health benefits, it is essential for it to be absorbed from the bloodstream into the cells. While some vitamin C products may be reasonably well absorbed from the gut into the bloodstream, they struggle to enter cells because of the vitamin C structure. Once vitamin C levels in the blood reach a certain level, they do not increase further, no matter how much vitamin C is consumed. To increase levels in the body, there needs to be increased movement of vitamin C out of the blood into the cells, which is what the vitamin C metabolites found in Ester-C enable. 
  •  Ester-C® is the only form of vitamin C which shows unprecedented uptake into and retention in immune cells for 24 hours. It boasts an impressive 10x greater white blood cell bioavailability than standard vitamin C.

Ester-C® - calcium ascorbate & vitamin C metabolites

  • Ester-C® is a patented formulation combining vitamin C with calcium in a chemical-free, water-based process. This results in a pH-neutral blend of calcium ascorbate and vitamin C metabolites, mainly dehydroascorbate and calcium threonate. Dehydroascorbate is the form of vitamin C able to cross the blood-brain barrier. 
  •  Calcium ascorbate delivers all the standard vitamin C benefits; however, vitamin C metabolites make Ester-C unique. 
  •  As Ester-C® contains different forms of vitamin C, it is absorbed quickly and efficiently through different pathways into the blood. This may benefit those genetically predisposed to decreased vitamin C absorption. The different forms are also absorbed optimally in different parts of the gut, which may benefit those with absorption issues. 
  • Vitamin C metabolites boost the uptake of vitamin C into immune cells. Ester-C maintains high levels of vitamin C in cells for 24 hours, making 1-a-day dosing effective.

Superior absorption & 24-hour action

  • For vitamin C to perform its functions and exert its health benefits, it is essential for it to be absorbed from the bloodstream into the cells. While some vitamin C products may be reasonably well absorbed from the gut into the bloodstream, they struggle to enter cells because of the vitamin C structure. Once vitamin C levels in the blood reach a certain level, they do not increase further, no matter how much vitamin C is consumed. To increase levels in the body, there needs to be increased movement of vitamin C out of the blood into the cells, which is what the vitamin C metabolites found in Ester-C enable. 
  •  Ester-C® is the only form of vitamin C which shows unprecedented uptake into and retention in immune cells for 24 hours. It boasts an impressive 10x greater white blood cell bioavailability than standard vitamin C.

How is Ester-C® better than standard vitamin C?

  • Ester-C® has been studied for decades, and is better researched than all other forms of buffered vitamin C. 
  •  Standard vitamin C is absorbed from the gut into the bloodstream fairly well at low doses (up to 200mg), but mega-dosing on standard vitamin C will not lead to raised levels in the blood after a certain level is reached. Standard vitamin C struggles to enter the cells of the body because of its structure, so it is quickly flushed from the body. 
  • Large doses of standard vitamin C are acidic and can irritate the gut, especially at a high dose, causing abdominal cramps, nausea and diarrhoea. Ester-C combines vitamin C with calcium in a chemical-free, water-based process, resulting in a pH-neutral blend so it’s gentle on the stomach. 
  • Achieving high levels in the body with standard vitamin C doses would require dosing repeatedly throughout the day and night. Ester-C®, however, can be taken as 1 tablet per day as it gets into and stays at high levels in immune cells for 24 hours.

Why choose Ester-C® over other forms of optimised vitamin C?

Ester-C® vs slow-release vitamin C

Studies do not support significant benefits of slow-release vitamin C compared to even standard vitamin C.  

Ester-C® vs liposomal vitamin C

Ester C® is superior to liposomal vitamin C in terms of its uptake and retention in immune cells. Although liposomal vitamin C does raise levels of vitamin C in the bloodstream effectively, it is the absorption of vitamin C into cells which is the crucial factor for it to perform its function.

Our Ester-C® vs other Ester-C® products

Some other Ester-C® products use a bovine capsule shell. Our Ester-C® tablets contain no animal products.

How is Ester-C® better than standard vitamin C?

  • Ester-C® has been studied for decades, and is better researched than all other forms of buffered vitamin C. 
  •  Standard vitamin C is absorbed from the gut into the bloodstream fairly well at low doses (up to 200mg), but mega-dosing on standard vitamin C will not lead to raised levels in the blood after a certain level is reached. Standard vitamin C struggles to enter the cells of the body because of its structure, so it is quickly flushed from the body. 
  • Large doses of standard vitamin C are acidic and can irritate the gut, especially at a high dose, causing abdominal cramps, nausea and diarrhoea. Ester-C combines vitamin C with calcium in a chemical-free, water-based process, resulting in a pH-neutral blend so it’s gentle on the stomach. 
  • Achieving high levels in the body with standard vitamin C doses would require dosing repeatedly throughout the day and night. Ester-C®, however, can be taken as 1 tablet per day as it gets into and stays at high levels in immune cells for 24 hours.

Why choose Ester-C® over other forms of optimised vitamin C?

Ester-C® vs slow-release vitamin C

Studies do not support significant benefits of slow-release vitamin C compared to even standard vitamin C.  

Ester-C® vs liposomal vitamin C

Ester C® is superior to liposomal vitamin C in terms of its uptake and retention in immune cells. Although liposomal vitamin C does raise levels of vitamin C in the bloodstream effectively, it is the absorption of vitamin C into cells which is the crucial factor for it to perform its function.

Our Ester-C® vs other Ester-C® products

Some other Ester-C® products use a bovine capsule shell. Our Ester-C® tablets contain no animal products.

Be kind to your health

“We are living in a rapidly changing world that challenges us in new and unexpected ways. We believe evidence-based nutrition has an important role to play in helping us to protect and boost our wellbeing. At Igennus we empower people who are committed to investing in their health with high impact nutrition to lead a healthier and fuller life. Our supplements are expertly formulated by our in-house nutrition scientists to achieve superior bioavailability for maximum impact on your health."

Dr Jav Nazemi

CEO & Co-Founder 

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