Thorne Vitamin C with Flavonoids Review
THORNE Vitamin C 500 mg from Citrus Bioflavonoids from Oranges is a 90 count capsule supplement sold on Amazon. The listing highlights its formulation of vitamin C with natural citrus bioflavonoids, which the page says offers added antioxidant benefits for better cellular protection against free radicals within the body. The page groups the product benefits into immune support, healthy skin, and detox support. Under Healthy Skin, the listing states that vitamin C promotes collagen production, which enhances skin, nail, and hair health and supports healthy tissue and cartilage formation. Under Detox Support, the page says the product promotes the body's natural ability to eliminate toxins and benefits liver health by helping increase glutathione and other potent antioxidants. The item highlight reads: Supports Optimal Immune Function, Collagen Production and Liver Detoxification, Antioxidant Properties, NSF Contents Certified. The listing states the product has been third-party tested and certified to verify that what is in the package matches what is on the label and to confirm it contains no unsafe levels of contaminants. The page also says Thorne is trusted by 100 plus professional sports teams and describes it as the number one most recommended clinical brand by consumers and health-care practitioners, based on a 2026 independent survey of US supplement consumers and health-care practitioners. Item details list the item form as capsule, primary supplement type as vitamin C, diet type as gluten free, and flavor as unflavored. The dosage form is capsule, the unit count is 90 count, and the item weight is 2.88 ounces. The item dimensions are 2.58 by 2.58 by 4.5 inches. The manufacturer is listed as Thorne Research, with model number C154 and manufacturer part number C154. The specific use listed is skin, the age range is adult, and the special ingredient listed is citrus bioflavanoids. The best sellers rank shows number 1,668 in Health and Household and number 9 in Vitamin C Supplements. The page shows a price of 23.00 dollars for the one-time purchase, with a Subscribe and Save price of 21.85 dollars or 20.70 dollars with 10 percent savings on repeat deliveries. The item is sold by Pattern and ships from Amazon, and it is non-returnable due to food safety reasons unless it arrives damaged or defective. The page also lists related Thorne products, including Thorne Iron Bisglycinate, Thorne Vitamin D-5,000, and Thorne Vitamin C 1,000 mg, but these are separate listings.
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Study, Trial or Testing Result Summary
Members Only39 human studies · 15 improved
2 of these 39 human studies gave the ingredient by injection, not by mouth.
At the daily amount on this label, 1,500 milligrams, vitamin C is well above the 200 milligrams that worked in studies. A pooled review of 29 placebo-controlled trials with 11,306 people found that colds were not less common in the general public. They were about half as common in marathon runners, skiers and soldiers, and colds were 8 percent shorter in adults and 14 percent shorter in children [1]. A review of 10 trials found cold severity was 15 percent lower with at least 1 gram daily [2]. Another pooled analysis found a 4 percent lower risk of respiratory infections and 9 percent shorter symptoms [3]. In 1,444 army recruits taking 6,000 milligrams daily, cold risk was 20 percent lower than with placebo [4]. However, a review of eight reviews concluded vitamin C does not prevent catching colds [5]. An older trial in marine recruits found colds were no less common or shorter [6]. The citrus bioflavonoids are a mix, and the daily 225 milligrams is below the 292 milligrams of hesperidin tested in the only human study. That small trial found no change in immune cells or immune activity [7]. Animal and cell studies are never counted.
See all 39 studies →Hide the studies
- Across 29 placebo-controlled trials with 11,306 people taking at least 0.2 g of vitamin C daily, colds were not less common in the general public but were about half as common in marathon runners, skiers and soldiers, and colds lasted 8% shorter in adults and 14% shorter in children.Vitamin C for preventing and treating the common cold.
- A review of eight systematic reviews covering 31 randomized trials concluded that taking vitamin C does not prevent people from catching a common cold.Does vitamin C prevent the common cold?
- In a pooled analysis of randomized trials in adults, vitamin C slightly lowered the risk of respiratory infections by 4% and shortened symptoms by 9%, with a stronger prevention effect in men and in middle-income countries.Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic revie…
- In 10 placebo-controlled trials of healthy people taking at least 1 g of vitamin C daily, cold severity was 15% lower than with placebo, with a clear benefit on severe symptoms but not on mild ones.Vitamin C reduces the severity of common colds: a meta-analysis.
- Five small, low-quality trials with 2,655 children and adults gave vitamin C at 125 mg to 2 g daily, and the evidence was too weak to tell whether it prevents or treats pneumonia.Vitamin C supplementation for prevention and treatment of pneumonia.
- A review of 39 randomized trials of eight supplements, including vitamin C, in healthy people under stress found some signs of benefit but too many gaps to draw firm conclusions about immune protection.Select Dietary Supplement Ingredients for Preserving and Protecting the Immune System in Healthy Individuals: A Systemat…
- A review of 13 studies in healthy adults found alternative vitamin C forms often raised white blood cell vitamin C and were better tolerated, with one study showing fewer colds, but more research is needed to confirm immune benefits.Enhanced Vitamin C Delivery: A Systematic Literature Review Assessing the Efficacy and Safety of Alternative Supplement …
- In 1,444 army recruits taking 6,000 mg of vitamin C daily for 30 days, the risk of getting a common cold was 0.80 times that of those taking placebo.Vitamin C supplementation reduces the odds of developing a common cold in Republic of Korea Army recruits: randomised co…
- In 868 Navajo schoolchildren given vitamin C or placebo, there was no difference in how many got ill (133 vs 129), number of illness episodes, or illness length, though blood vitamin C levels were higher.Vitamin C and acute illness in Navajo schoolchildren.
- In a randomized trial of 688 adult women, 1 gram of vitamin C daily produced a small reduction in chest colds but no effect on simple colds.A randomized controlled trial of vitamin C in the prevention and amelioration of the common cold.
- In 674 marine recruits given 2 grams of vitamin C or placebo daily for eight weeks, colds were no less common or shorter, though the vitamin C group rated their colds as less severe.Vitamin C prophylaxis in marine recruits.
- In 595 critically ill surgical patients, early antioxidant supplementation with vitamin C and vitamin E did not significantly reduce lung complications compared with standard care, but it reduced multiple organ failure and shortened time on the ventilator and in intensive care.Randomized, prospective trial of antioxidant supplementation in critically ill surgical patients.
- In a 5-year double-blind trial of older Japanese adults, 500 mg of vitamin C daily cut the number of people with three or more colds, compared with 50 mg daily, but did not shorten or lessen the colds.Effect of vitamin C on common cold: randomized controlled trial.
- In 275 people with early COVID-19, a 10-day combination therapy including vitamin C was safe and well tolerated, but the study did not test whether it improved immune health.Read the study on PubMed (41693032) →
- In 311 National Institutes of Health employees taking 3 g of ascorbic acid daily for nine months (with extra doses at cold onset), the vitamin had at best a minor effect on the duration and severity of colds, and the results could be explained by a break in blinding.Ascorbic acid for the common cold. A prophylactic and therapeutic trial.
- In a double-blind study of 95 identical twin pairs over 100 days, vitamin C shortened cold episodes by about 19% but had no other significant effect compared with placebo.Vitamin C and the common cold: using identical twins as controls.
- In 120 stroke patients with swallowing difficulty, vitamin C stimulation added to routine swallowing training improved swallowing tests, nutrition markers and antibody levels compared with routine training alone.Effects of vitamin C stimulation on rehabilitation of dysphagia after stroke: a randomized trial.
- In 98 adults with mild to moderate coronavirus illness, 1000 mg of vitamin C daily for 14 days had no effect on symptom progression or quality of life compared with placebo.A Pilot of a Randomized Control Trial of Melatonin and Vitamin C for Mild-to-Moderate COVID-19.
- In 60 children prone to recurrent respiratory infections, a daily orange juice providing 70 mg of vitamin C was associated with a drop in infection episodes from about 6.75 to 2.62 per child.Beneficial therapeutic effects of vitamin C on recurrent respiratory tract infections in children: preliminary data.
- In 28 people recovering from COVID-19, a single 1000 mg dose of vitamin C reduced one type of immune-related reactive oxygen species by 45% but did not raise nitric oxide levels.A Plant-Based Dietary Supplement Exhibits Significant Effects on Markers of Oxidative Stress, Inflammation, and Immune R…
- In 24 patients receiving stem cell transplants for myeloma or lymphoma, high-dose vitamin C (20 g daily for 10 days, then 500 mg twice daily until day 100) was linked to rising natural killer and CD3 immune cell counts from day 30 to day 100 and fewer infections, compared with standard care alone.Effect of vitamin C on immune reconstitution after bone marrow transplantation.
- In 24 healthy men in a crossover study, taking 292 mg of hesperidin daily or drinking 500 mL of orange juice for 4 weeks did not change immune cell counts, natural killer cell activity, neutrophil ROS production or cytokine production compared with placebo.Orange juice and its major polyphenol hesperidin consumption do not induce immunomodulation in healthy well-nourished hu…
- In 20 children having surgery, ascorbate before premedication did not change neutrophil mobility during anaesthesia or surgery, and no infections occurred.Neutrophil mobility during anaesthesia in children. A trial of ascorbate premedication.
- In 12 adults who exercised for about two hours in heat, 1500 mg of vitamin C daily for 12 days lowered the stress hormone cortisol after exercise, but did not change salivary antibody levels or cold-like symptoms compared with placebo.Vitamin C supplementation and salivary immune function following exercise-heat stress.
- In healthy adults aged 55 and older, a 12-week multivitamin and mineral supplement raised blood vitamin C and zinc levels but did not change measured immune function compared with placebo.The Effect of a Multivitamin and Mineral Supplement on Immune Function in Healthy Older Adults: A Double-Blind, Randomiz…
- In older adults, a 30-day course of a multi-ingredient supplement that also contained vitamin C lowered inflammatory blood markers and improved lymphocyte levels, though they did not reach the levels seen in younger people; the vitamin C dose was not stated.Use of Nutraceuticals in Elderly to Fight Inflammation and Immuno-Senescence: A Randomized Case-Control Study.
- In a randomized trial of ultramarathon runners and sedentary controls, taking 600 mg of vitamin C daily was linked to fewer upper airway infection symptoms in the two weeks after a race than placebo, with 33% of supplement takers developing symptoms versus 68% of placebo takers among runners.Vitamin C supplementation reduces the incidence of postrace symptoms of upper-respiratory-tract infection in ultramarath…
- In two trials of 8-9 year old children (172 and 642) given 1000 mg vitamin C daily, cold duration and severity seemed lower but cold incidence stayed the same or rose, and the total sick days were fewer only in the smaller pilot study.Vitamin C as a preventive medicine against common colds in children.
- In about 210 students (three groups of about 70) taking 1 gram daily for 15 weeks, the D-isoascorbic acid group had 34% fewer colds than the other two groups, which included the L-ascorbic acid group, so regular vitamin C showed no clear benefit.L-Ascorbic acid and D-isoascorbic acid in a common cold survey.
- In a large double-blind trial, 1 g of vitamin C daily gave a small, non-significant reduction in colds, but more people stayed illness-free and vitamin takers had about 30% fewer days of disability from illness than placebo takers.Vitamin C and the common cold: a double-blind trial.
- In older adults, 500 mg of vitamin C injected daily for one month improved T-lymphocyte response and skin test reaction compared with placebo, but did not change antibody levels.Effect of vitamin C supplements on cell-mediated immunity in old people.
- In a small feasibility study of people with a new common cold, 250 mg of vitamin C daily for 5 days was used only as the comparison arm against a warm humidified air treatment, and the abstract reports no benefit from vitamin C itself.Randomised controlled trial of rhinothermy for treatment of the common cold: a feasibility study.
- In a study of 433 women followed for a year, those with the highest dietary vitamin C intake were less likely to have a persistent human papillomavirus infection than those with the lowest intake.Dietary intake and risk of persistent human papillomavirus (HPV) infection: the Ludwig-McGill HPV Natural History Study.
- In hospital records of patients with upper respiratory tract infection, adding vitamin C injection to Xiyanping injection did not improve cure rates compared with Xiyanping alone.[Analysis of actual effects of combining xiyanping injection with vitamin C injection in treatment of upper respiratory …
- In rats given hesperidin for 15 days before endotoxin exposure, endotoxemia, inflammatory cytokines and oxidative stress were reduced; no human participants were studied.Hesperidin prevents lipopolysaccharide-induced endotoxicity in rats.
- In infected rabbits, hesperidin methyl chalcone, a citrus flavonoid derivative, reduced granuloma formation and lowered inflammatory signals over 10 weeks; no human participants were studied.Hesperidin methyl chalcone alleviates spinal tuberculosis in New Zealand white rabbits by suppressing immune responses.
- In laboratory and mouse tests, a Petasites japonicus extract slowed malaria parasite growth and reduced platelet clumping linked to the infection; no human participants were studied.Petasites japonicus extract exerts anti-malarial effects by inhibiting platelet activation.
- In mice infected with Helicobacter pylori, Cudrania tricuspidata leaf extract, which contains rutin, reduced inflammatory cytokines and stomach inflammation over 6 weeks; no human participants were studied.Protective Effects of Cudrania tricuspidata Against Helicobacter pylori-Induced Inflammation in C57BL/6 Mice.
- A rutin-containing hydrogel dressing reduced inflammatory markers in macrophage cells and sped wound healing in mice; no human participants were studied.Chitosan/rutin multifunctional hydrogel with tunable adhesion, anti-inflammatory and antibacterial properties for skin w…
Review Totals and Summary
Members Only3,765 reviews · 98% positive
This summary draws on reviews from iHerb and a smaller sample from the retailer Fuel Goods. The sample is limited and the retailer reviews skew positive, so treat it as a partial picture. Customers most often praise Thorne's quality and trustworthiness. Many say they chose it because of the brand's reputation. They like that it has no unnecessary fillers or additives, and several mention the third-party certification as a reason they trust it. A recurring theme is gentleness on the stomach. Some buyers say it does not cause the upset they got from other vitamin C supplements. Several see the added flavonoids as a worthwhile extra that makes the capsule feel more effective than plain ascorbic acid. People also report subjective benefits. They mention noticeable skin improvements, immune support, and relief from seasonal allergy symptoms. Some say they can feel a difference compared with other brands. Practical points get positive comments too. Reviewers like the convenient 500 mg capsule, the practical packaging, and the 90-count bottle as good value for regular use. Criticism is much rarer in the material I could read. The main reservation is that some users notice no effect at all. One reviewer wrote that they didn't notice anything, which is common with a nutrient whose benefits are preventive and subtle. The premium price is the other likely complaint. I did not see it come up directly in the sample, so that part is an inference. Overall, customers describe a reliable, clean, well-tolerated vitamin C. Its appeal rests on brand trust and gentle digestion more than on dramatic, immediately felt results.
Biohacker Summary
Members Only8 of 10 recommend it
Most of the panel recommends or uses vitamin C, though a few stayed neutral and one stopped. The most common reasons are collagen support for skin, joints and connective tissue, and immune support, with several suggesting taking it together with collagen, one saying to take it about an hour before a workout. Doses vary: one panelist takes 250 milligrams, another suggests about a gram a day split into divided doses, one takes an extra gram, one mentions 500 milligrams at the first sign of a cold, and one cites 2 to 4 grams for inflammation. Forms mentioned include liquid liposomal, natural food sources, and topical serums for skin. The caution comes from one panelist who warned that high doses might not always help and could blunt the benefits of exercise, and one who stopped a vitamin C serum because of its smell.
See all 10 biohackers →Hide the biohackers
Ben Greenfield · Vitamin C · recommends
- States that vitamin C is extremely important for collagen turnover and cites orthopedic data showing that 500 mg to 1 g of vitamin C can reduce the rate of complex regional pain in total knee replacements and wrist fractures.
- Mentions vitamin C as part of a bare-minimum protocol.
- Notes that while vitamin C has significant value, the optimal dose is a vexed question, and high doses might not always be beneficial, potentially blunting the hormetic effects of exercise.
- Notes that IV vitamin C has been used for decades for cancer patients with almost no standardization and that he receives many questions about its effectiveness and combination with chemo.
- Recommends Vitamin C for skin repair post-tattoo.
- Does not agree that ascorbic acid is vitamin C, comparing it to calling chaff wheat, and notes that it is made from genetically modified cornstarch or corn syrup byproducts using solvents.
- Warns against ascorbic acid, stating that it does not cure scurvy and that the world has been led astray by the deception around it versus the whole food vitamin C complex.
- Warns against taking 1,000 mg of vitamin C immediately after a workout for individuals under 50, as it can dull the body's natural adaptation signal.
- Warns that using high-dose antioxidants like vitamin C directly before or after a hyperbaric session is not a great idea, as it could impair some of the effects by reducing reactive oxygen species.
- Warns that taking a whole bunch of antioxidants like vitamin C after a workout can suppress the body's inflammatory response, which is necessary for benefits like mitochondrial proliferation and satellite cell generation for new muscle.
- Notes that citrus fruits (lemon, orange, mango) are among the fruits most associated with decreased risk of colorectal cancer.
- Recommends including a lot of citrus fruits in the diet for their importance in epithelial support.
- Says he is focusing on bioflavonoids from pomegranate, blueberry, and cranberry to activate beneficial bacteria to grow.
- Ben Greenfield, having predominantly northern European ancestry, says he would not necessarily benefit from a large intake of citrus fruits.
Siim Land · Vitamin C · recommends
- Recommends taking vitamin C with collagen to support joint collagen synthesis.
- States that vitamin C is needed for initiating collagen synthesis and that higher vitamin C intake appears to increase vitamin C content in the skin.
- Lists sauerkraut and fruit as sources of Vitamin C.
- Notes that Vitamin C is one of several supplements with human evidence.
- Notes that researchers found vitamin C alleviates ferro-aging, a process of iron overload and lipid peroxidation that drives aging, and that it directly inhibited ACSL4, a protein driving ferro-aging.
- States that Vitamin C has a central role in aging and longevity, and that in monkeys, oral vitamin C slowed ovarian aging during a 3.3-year study.
- States that vitamin C is one of the most important vitamins for staying healthy and aging well, and that intakes of 200 to 400 mg a day from food or supplements largely saturates plasma and neutrophils in most healthy adults. He also recommends spreading out the vitamin C across the day to avoid oversaturation.
- Recommends citrus fruits for skin health.
- Mentions vitamin C in comparison to topical melatonin for oxidative defense, stating that melatonin would compete but is not as broadly validated clinically.
- Was found to be vitamin C deficient by True Health and Mayo Clinic tests, and now addresses this by eating one extra kiwi fruit daily.
- States that the biggest evidence for multivitamin is that it improves cognition and enhances episodic memory in elderly people, who tend to have worse diets and are more likely to be deficient.
- States he eats watermelon and other citrus fruits quite regularly because they contain citrulline, which increases nitric oxide production.
Dr. Eric Berg · Vitamin C · neutral
- Mentions that lemon is loaded with vitamin C, and when combined with coffee, vitamin C significantly increases the bioavailability of antioxidants in the coffee.
- Dr. Berg states that Vitamin C helps fight biofilms and is essential for making collagen in gums, teeth, and capillaries.
- Recommends Vitamin C as a cofactor, especially for collagen.
- States that high doses of vitamin C, like 2 to 4 grams, can greatly reduce inflammation and support the immune system.
- Highly recommends taking natural food vitamin C, about 500 mg, at the first sign of a cold.
- Recommends consuming foods high in vitamin C to block the effects of grains.
- Recommends ensuring that collagen supplements come with vitamin C.
- Vitamin C works as an antioxidant that supports skin and artery health.
- Recommends pairing collagen with vitamin C to support absorption.
- Recommends consuming citrus fruits to increase nitric oxide.
- Sauerkraut also contains vitamin C and beneficial bacteria that may support digestive health.
- Recommends citrus fruits like lemon, lime, and grapefruit for their vitamin C, which supports the immune system in cancer prevention, and flavonoids that strengthen the liver's ability to turn carcinogens into harmless particles, decreasing the risk for certain types of cancer, especially of the digestive system.
- Recommends consuming the white part and outer peel of lemons or limes to get a tremendous amount of bioflavonoids (P factor), which are part of the vitamin C complex and can help tighten vascular junctions, preventing symptoms like bleeding gums and reducing complications from diabetes.
- Identifies bioflavonoids as one of the two compounds isolated from hawthorne berry extract that create the most effect, specifically relaxing the coronary artery.
Thomas DeLauer · Vitamin C · recommends
- Recommends taking vitamin C along with collagen about an hour before a workout for connective tissue benefits.
- Uses vitamin C as part of their immunity duo, stating it is important for boosting the immune system, especially during cold and flu season.
- Recommends consuming vitamin C to aid in NADPH recycling, which is necessary for glutathione to be reused after neutralizing oxidative stress.
- Takes Purity's liquid liposomal vitamin C for immune support and overall wellness, finding it easy to add to water, juice, or take straight up due to its good taste.
- Compares the Vitamin C content of oranges (53mg) to guava (228mg), noting guava has 4x more.
- States that collagen synthesis is vitamin C dependent, in the context of glowing skin.
- Recommends Vitamin C for sleep, noting that intake in the range of 125 to 200 mg per day is associated with a lower risk of sleep disorders and sleep apnea, with the benefit plateauing beyond this range.
- Recommends consuming a little bit of vitamin C, such as a couple of berries or kiwi, along with flavanol-rich cocoa to help the delicate flavanols hold up and prevent oxidation in the gut.
- Explains that vitamin C improves the ability of neutrophils to engulf bacterial infections, and that they have a greater ability to engulf larger infections.
- Recommends using a multivitamin to ensure adequate micronutrient intake, especially when wholesome food is less available.
- Warns that citrus fruits are heavy histamine liberators, meaning they trigger immune cells to release histamine, which can lead to brain fog by binding to the H3 receptor.
Dave Asprey · Vitamin C · recommends
- Recommends taking vitamin C for better skin health.
- States that currently, he is only taking vitamin C and vitamin D.
- Dave Asprey reflects on how new research clarifies the mechanism behind IV vitamin C's anti-cancer effect, vindicating a decades-old idea that was dismissed for the wrong reasons.
- Notes that plain Vitamin C isn't enough and that most people never think to check for a specific ingredient that makes it work.
- Dave Asprey recommends taking maybe a gram of vitamin C a day in divided doses, noting that plasma levels peak around 250 milligrams twice a day.
- Recommends Qualia Vitamin C Plus, highlighting its combination of seven forms of vitamin C with 250 mg of citrus bioflavonoids, which helps with absorption and use for building collagen and a strong immune system.
- Recommends Qualia Vitamin C Plus, highlighting its combination of seven forms of vitamin C with 250 mg of citrus bioflavonoids, which helps with absorption and use for building collagen and a strong immune system.
- Warns that taking too much vitamin C can raise oxalate levels, emphasizing that everything has risk and reward.
- Recommends Vitamin C as the real biological fix for deep focus issues, explaining how the brain hoards it at levels 100 times higher than blood and how to bypass the blood-brain barrier.
- States that Ensure is like SlimFast but worse, and that its ingredients, including synthetic vitamins, guar gum, maltodextrin, high fructose corn syrup, and seed oils, are disgusting and should not be given to sick or well people.
- Recommends IV Vitamin C, or even oral versions, for helping the body heal and for cells to remain supple and fluid.
- Warns that citrus fruits can be problematic for those with histamine sensitivity.
Dr. Mark Hyman · Vitamin C · recommends
- Recommends vitamin C as a basic supplement during detoxification to help with inflammation and detoxification.
- Dr. Hyman mentions vitamin C as an advanced therapy for skin repair.
- Mentions topical vitamin C as an antioxidant that can help skin with aging.
- Mentions that what they do when a cold comes on is not just vitamin C.
- Recommends ensuring adequate vitamin C intake on a regular basis for immune support, stating it's important for healthy immune function despite mixed data on its effectiveness for colds.
- Mentions that vitamin C was the very first vitamin discovered, isolated, and synthesized in 1932, and its deficiency caused scurvy.
- Recommends nutrient-dense foods rich in vitamin C, such as guavas and parsley, to reduce inflammation.
- Used intravenous vitamin C cocktails to help him detoxify and recover from chronic fatigue.
- Recommends vitamin C for immune system support and modulation.
- Relies on Big Bold Health's HTB Immune Energy Chews, which deliver 1000mg of sprouted Himalayan tardy buckwheat, along with vitamin C, D, magnesium, and zinc, to support immune balance, resilience, energy, and focus.
- Recommends citrus fruits as a source of polyphenols to help stay ahead of the cold and flu season.
- Mentions oranges and other citrus fruits as sources of vitamin C.
- Recommends oranges and other citrus fruits as a source of Vitamin C, but warns against juice due to high sugar content.
- Recommends bioflavonoids like quercetin, found in colorful plant foods, orange peels, and onions, for circulation and the lymph system.
Dr. Rhonda Patrick · Vitamin C · neutral
- Lutein and zeaxanthin can also be obtained from certain multivitamins.
- Recommends nutrients like vitamin C for men to prioritize sperm mitochondrial health.
- Dr. Rhonda Patrick's daughter chugs an Emergency fizzy drink in the morning to ensure she gets some vitamin C and micronutrients before school.
- Choosing a multivitamin that includes lutein and zeaxanthin ensures you get meaningful amounts every day.
- Notes that ~35% of Americans are low in vitamin C.
- Recommends increasing vitamin C intake if concerned about skin aging, noting it is an essential cofactor for collagen synthesis.
- Suggests avoiding a multivitamin if it contains biotin before a testosterone blood test to prevent confounding results.
- Multiple randomized controlled trials show older adults taking a standard multivitamin (like Centrum Silver) had measurable improvements in processing speed, cognition, and episodic memory.
- Currently takes the Pure Encapsulations O.N.E Multivitamin.
- Rhonda's current supplement routine includes Vitamin C.
Andrew Huberman · Vitamin C · uses
- Takes a multivitamin every day for longevity.
- Recommends AG1, a vitamin, mineral, and probiotic drink, and notes that for a limited time, a subscription comes with additional supplements.
- Takes an extra gram of vitamin C a day for its effects on immunity and potential synergy with collagen.
- Found the Met RX Big 100 Bar to be 'magic' on the trail because it's a hunk of calories with protein and fortified with vitamins and minerals, despite being something they would never eat in normal life.
- Started taking AG1 in 2012 and still takes it every single day to ensure he meets his quota for daily vitamins and minerals and to support gut health, which is critical for proper brain function, immune system, and neurotransmitter production.
- Has been taking AG1 daily since 2012 because it is the highest quality and most complete foundational nutritional supplement, ensuring he gets all necessary vitamins, minerals, and micronutrients for daily health.
- Has been drinking AG1 since 2012, finding it difficult to get enough vitamins, minerals, micronutrients, and adaptogens from diet alone. He finds that taking AG1 daily improves all aspects of his health, including physical and mental health, performance, recovery from exercise, and immune system strength, and also notices more mental clarity and energy.
- Recommends AG1 as the highest quality and most complete foundational nutritional supplement, containing vitamins, minerals, probiotics, prebiotics, and adaptogens to cover dietary gaps and support a demanding life.
- States that AG1 is the highest quality and most complete foundational nutritional supplement available, containing vitamins, minerals, probiotics, prebiotics, and adaptogens, and that he has been taking it daily since 2012, often twice a day, to bolster his energy, immune system, and gut microbiome.
- Huberman mentions that vitamin C seems to help with the absorption or utilization of collagen protein.
Peter Attia · Vitamin C · stopped
- Recommends vitamin C as an important molecule for skin, noting its role as a precursor for collagen synthesis, a powerful antioxidant, and a regulator of complexion for even skin tone.
- Tried a vitamin C serum mixed with ferulic acid but stopped using it because she hated the smell. She notes that topical application of vitamin C far exceeds the levels achievable by ingestion for skin benefits.
- States that vitamin C deficiency is associated with an elevated risk of cataract, but supplementation to supranormal levels has not been shown to protect against cataract formation.
- Mentions the elimination of scurvy through the work of James Lind and the eventual understanding that it was due to vitamin C, initially thought to be just citrus.
- Notes that while vitamin C deficiency is associated with an elevated risk of cataract, supplementation to supranormal levels has been conclusively shown not to protect against cataract formation.
- Mentions that a survey of doctors showed they recommend Vitamin C for COVID-19, but notes there is no real evidence behind it.
- Expresses skepticism about 'panacea treatments' for cancer, specifically mentioning a 'twenty thousand dollars of vitamin C' treatment, implying it's an example of something he's 'squirrely' about due to cost and unproven claims.
- Asks if vitamin C matters for immune function, suggesting a need for a definitive study.
- Warns against the "total nonsense" of taking excessive amounts of vitamin C, especially in specific forms like liposomal vitamin C, for immunity, stating that it is idiotic and potentially dangerous to think it will offer immunity.
- Would love to see more research done on mega dose intravenous vitamin C for viral infections, noting some interesting but not followed-through research from the 1960s.
Bryan Johnson · Vitamin C · neutral
- Uses Vitamin C as an example of how it would be great if people knew that when they took it, it had a measurable amount and wasn't polluted, which is what Brian ensures with his products.
- Applies vitamin C after showering.
- Takes 250 milligrams of Vitamin C.
- Recommends Vitamin C for skin health, noting it's good to pair with collagen peptides and is included in the Blueprint stack.
- Bryan Johnson takes Vitamin C daily as part of his Longevity Mix, which is an antioxidant-rich essential vitamin that supports immune function and metabolic energy.
- He uses Vitamin C, typically in a serum, in the morning for skin health.
RAL Summary
Members OnlyTier 2 for Immune Health
More Details
Members OnlyBody systems · Combine with · Possible side effects
Body systems: Immune system, Respiratory system
Combine with: For immune and antioxidant support, Vitamin C pairs well with zinc, vitamin D3 with K2, and quercetin, which work synergistically with vitamin C. Vitamin E and glutathione or NAC support antioxidant recycling, and iron absorption improves when vitamin C is taken with non-heme iron if needed. For post-meal upper-abdominal comfort, look at separate products with broad-spectrum digestive enzymes, ginger, peppermint oil, or bitters such as gentian or artichoke leaf. Consider taking vitamin C with food, or choosing a buffered form, if it causes stomach upset.
Possible side effects: No major side effects reported.
Supplement Facts
Vitamin C 500 mg · Citrus Bioflavonoids 75 mg
| Vitamin C | 500 mg | |
| Citrus Bioflavonoids | 75 mg | † |
Other ingredients: Cellulose, Powder, Hypromellose, Calcium Laurate.
Directions: Suggested Use: Take 1 capsule one to three times daily or as recommended by your health-care practitioner.
Barcode (UPC) 693749012481 · Label source: NIH label database · Report a label change
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Graded November 5, 2026 by the Reverse Age Lab evidence engine, from human studies, real reviews and our biohacker panel. How we grade. Is this medical advice? No. Rala organizes the published evidence; go over any change with your doctor, especially if you take meds.
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