OmneDiem Histamine Digest with DAOgest 20,000 HDU Review
Histamine Digest with DAOgest 20,000 HDU by OmneDiem is a capsule supplement listed on HelloPharmacist with three active ingredients: Vitamin C 30 mg, Catalase 10 mg and DAO 4.2 mg. The label presents it for dietary histamine breakdown support. According to the label text shown on this page, many foods contain histamine or cause its release in the gut, and Diamine Oxidase (DAO) is described as the primary enzyme responsible for breaking down dietary histamine. OmneDiem states that this product delivers natural-source DAO in a designed-release capsule that dissolves in the small intestine, where it acts on dietary histamine. The DAO ingredient is listed on the label as DAOgest Porcine Kidney Extract, and the label notes that DAOgest is a trademark of Bioiberica, S.A.U. The label directs: Take one capsule 15 minutes before meals as needed. The serving size is 1 capsule, with 120 servings per container, and the net contents are 120 capsules. The Supplement Facts list Vitamin C at 30 mg (33% Daily Value), while the Daily Value for Catalase and DAO is not established. Other ingredients are Microcrystalline Cellulose, vegetarian capsule, Hypromellose, DRcaps and Silicon Dioxide. The label states it is Vegetarian Caps and does not contain wheat, gluten, yeast, soy, dairy products, fish, shellfish, peanuts, tree nuts, egg, GMO ingredients, artificial colors, artificial sweeteners or artificial preservatives. The page lists the product as gluten free and dairy free for adults 18 to 50 years. The label was entered into the NIH Dietary Supplement Label Database on January 23, 2025. The page also includes the label statement that the product has not been evaluated by the Food and Drug Administration and is not intended to diagnose, treat, cure, or prevent any disease. HelloPharmacist notes that Vitamin C has interaction records rated moderate, across 207 drugs, most notably a med, estrogens, alkylating agents and antitumor meds. Catalase and DAO have no interaction records on this page. Side effects commonly reported with the Vitamin C component include upset stomach, nausea, stomach cramps, diarrhea, heartburn and headache, with kidney stones noted as a rare but more serious concern at very high or long-term doses. The page states that the research rating reflects the ingredients in general rather than this exact product, and that it is a summary of what is known, not a grade or test of the product.
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Study, Trial or Testing Result Summary
Members Only23 human studies · 5 improved
The main ingredients here, the enzyme diamine oxidase and catalase, have no human studies in the evidence we reviewed, so we cannot say whether they help with gas, bloating or irregularity. The product also has 30 milligrams of vitamin C. No human trial has tested vitamin C on its own for these symptoms. Most controlled studies used vitamin C as part of a bowel-cleansing drink before colonoscopy. One review found that drink cleansed as well as other preps, with less vomiting and no difference in stomach pain [1]. One trial linked it to more bloating [2]. A large UK study linked moderate vitamin C intake, as part of an antioxidant-rich diet, to lower risk of irritable bowel syndrome [3]. Smaller studies of people with irritable bowel syndrome found no link between vitamin C intake and symptoms [4][5]. A study in chronic pancreatitis used 540 milligrams of vitamin C daily inside an antioxidant mix, far more than the 30 milligrams here, and did not test vitamin C alone [6]. Overall, the evidence for this product and this goal is thin. Animal and cell studies are never counted.
See all 23 studies →Hide the studies
- Across six studies of 3,285 adults, a low-volume bowel prep with vitamin C cleansed as well as the comparison prep and caused less vomiting, with no difference in nausea or abdominal pain.Efficacy and safety of split-dose ultra-low-volume polyethylene glycol with ascorbic acid versus sodium picosulfate with…
- In 20 trials of 2,468 children preparing for colonoscopy, a bowel cleanser containing vitamin C was rated adequate but was tested in only one study, and no clear benefit for digestive symptoms was shown.Comparative Cleansing Efficacy, Safety, and Tolerability of Bowel Preparation Agents in Pediatric Patients: A Network an…
- In 206 adults having an afternoon colonoscopy, the 2-liter prep with vitamin C cleansed less well than a 4-liter prep without it and was linked to more bloating (23.1% vs 11.5%).Efficacy of morning-only 4 liter sulfa free polyethylene glycol vs 2 liter polyethylene glycol with ascorbic acid for af…
- In 196 adults with quiet ulcerative colitis, a 1-liter prep with vitamin C cleansed as well as the 2-liter dose (98.6% vs 97.1% success) but caused more nausea.One-liter polyethylene glycol with ascorbic acid provides comparable cleansing quality to two-liter regimen in bowel pre…
- In 168 adults, 1 liter of the vitamin C prep plus a suppository cleansed as well as the 2-liter prep, with similar abdominal pain and nausea but less sleep disturbance and anal discomfort.Combination of bisacodyl suppository and 1 L polyethylene glycol plus ascorbic acid is a non-inferior and comfortable re…
- In 55 people, the vitamin C bowel prep alone cleansed poorly in those with spinal cord injury (50% acceptable) versus 89% in able-bodied people, and adding neostigmine raised acceptable cleansing to 85%.Neostigmine Administered With MoviPrep Improves Bowel Preparation for Elective Colonoscopy in Patients With Spinal Cord …
- In 40 adults over 4 weeks, a hydration drink containing vitamin C among other ingredients was well tolerated, with only mild bloating and cramping changes and no meaningful harm versus placebo.Randomized Trial to Assess the Safety and Tolerability of Daily Intake of an Allulose Amino Acid-Based Hydration Beverag…
- In 313 people with chronic pancreatitis treated with a medical plan that included an antioxidant mix with 540 mg vitamin C daily, 84.7 percent had significant abdominal pain relief at one year, though vitamin C was not tested alone.Long-term pain relief with optimized medical treatment including antioxidants and step-up interventional therapy in pati…
- In 14 patients after upper gut surgery given 1500 mg vitamin C daily by feeding tube for 5 days, the high-dose feed was well tolerated, with flatulence in only 3 of 14 people.Safety and intestinal tolerance of high-dose enteral antioxidants and glutamine peptides after upper gastrointestinal su…
- In a large UK study of 157,900 adults followed for about 13 years, moderate intake of vitamin C within an overall antioxidant diet was linked to lower risk of irritable bowel syndrome, while very high intake gave no added protection.Nonlinear association between composite dietary antioxidant index and irritable bowel syndrome: insights from UK Biobank…
- In a national survey of 7042 American women, higher blood vitamin C levels were linked to a lower prevalence of gallbladder disease and gallstones, but no link was found in men.Serum ascorbic acid and gallbladder disease prevalence among US adults: the Third National Health and Nutrition Examinat…
- In a case-control study of Iranian adults, a nutrient pattern high in antioxidants including vitamin C was linked to lower odds of irritable bowel syndrome, but this was an association and vitamin C was not tested alone.The Relationship of Dietary Nutrient Patterns and Irritable Bowel Syndrome: A Multicenter Case-Control Study.
- In a case-control study of 775 Lebanese adults, lower vitamin C intake was linked to food hypersensitivity (including gut symptoms), but this was an association and not a test of vitamin C.Nutritional Profile, Lifestyle Characteristics, and Intestinal Inflammation in Lebanese Adults Suffering from Food Hyper…
- In 555 young women, higher vitamin C intake and mid-range blood vitamin C levels were linked to more premenstrual appetite changes and bloating or swelling.Associations Between Dietary Vitamin C, Serum Ascorbic Acid, and GSTT1 Genotype and Premenstrual Symptoms.
- In a questionnaire survey of Romanian adults with anemia, vitamin C had mixed results in easing treatment side effects such as stomach discomfort.Impact of Side Effects on Anemia Therapy Compliance.
- Women with endometriosis had more gastrointestinal symptoms such as flatulence and constipation than controls and lower dietary vitamin C intake, but the study did not test vitamin C as a treatment.Different nutrient intake and prevalence of gastrointestinal comorbidities in women with endometriosis.
- People with irritable bowel syndrome ate more vitamin C from food than matched controls, but vitamin C intake was not linked to symptom severity or bowel subtype.Nutrient intake in patients with irritable bowel syndrome compared with the general population.
- In 155 adults with irritable bowel syndrome, vitamin C intake was low in many participants, but the study did not link vitamin C intake to bowel symptoms.Intake of fiber and micronutrients in patients with IBS.
- In a retrospective study of 146 children, an oral sulfate tablet worked as well as a polyethylene glycol and ascorbate bowel prep for colonoscopy, with less abdominal pain. This tested bowel-cleansing products, not vitamin C as a digestive aid.Efficacy and safety of oral sulfate tablet vs. polyethylene glycol and ascorbate for bowel preparation in children.
- In 53 people with irritable bowel syndrome, vitamin C intake was high from diet, and higher fiber intake was linked to fewer general symptoms. Vitamin C itself was not linked to symptoms.[Dietary intake of a group of patients with irritable bowel syndrome; relation between dietary fiber and symptoms].
- In a 1988 study of 45 people (chronic pancreatitis patients, epilepsy patients on enzyme-inducing drugs, and controls), vitamin C intake was one of several factors that separated the groups, but no vitamin C supplement was given and no digestive symptoms were measured.Antioxidants, enzyme induction, and chronic pancreatitis: a reappraisal following studies in patients on anticonvulsants…
- In a 1985 dietary survey of gastroenterology outpatients, women with functional bowel and reflux disorders had lower vitamin C intake than women with inflammatory bowel disease. No vitamin C supplement was tested and symptoms were not linked to vitamin C.Nutritional status of gastroenterology outpatients: comparison of inflammatory bowel disease with functional disorders.
- In a retrospective study of people with irritable bowel syndrome, a low FODMAP diet group had greater symptom relief than a regular diet group and higher vitamin C intake, but vitamin C itself was not tested as the cause of the benefit.Impact of low-FODMAP diet on symptom relief in irritable bowel syndrome patients.
Review Totals and Summary
Members Only6 reviews · 57% positive
Buyers are split, though more lean positive than negative. Several say these capsules worked when other DAO brands did not, while others saw no benefit or reported a quality problem with recent bottles. **What buyers say it did for them:** The happiest reviewers say it helps with histamine reactions to food. One says it is "The only brand of DAO that works for me." Another reports, "Taking daily for histamine intolerance and it is helping." A third says "These do work well for me," and adds that timing matters: take the capsules about 15 minutes before a meal and within half an hour of eating. Two people compare it with other brands and say it did better, though one adds that "everyone is different." **What they complain about:** The main complaint is that it simply did not work. One reviewer says it "did zero good" even after finishing the whole bottle and following the instructions. Another says it "doesn't work for me" and had "much better results" with a different DAO brand. A third complaint is about quality: a long-term user says recent bottles have "a bad burned smell and taste" that earlier ones did not, and wants an explanation from the company. That reviewer says they no longer trust the product. **Taste, smell, pill size or form:** Only one reviewer comments on this, and it is negative. They describe a burned smell and taste in recent bottles of capsules, which they did not notice before. Nobody else mentions taste, smell or capsule size. Reviews of other forms of this product were left out, and this summary covers the capsules only. **Value for money:** Opinions are mixed. One buyer tried four cheaper brands first and found that "None of them helped much," which suggests the higher price was worth it for them. Another says they got more of the active ingredient, DAO, than in any other product they found, and notes it is "Not full of unnecessary fillers." On the other side, the reviewer who saw no benefit calls it "What a waste of money!" and will not buy again. **Who it seems to suit and who it did not:** It seems to suit people with histamine intolerance who have tried other DAO products without success, and who will take the capsules shortly before meals. It did not suit people who felt no change, including some who had had better results with another brand. It also did not suit a long-time user who was put off by the change in smell and taste. As one reviewer puts it, results differ from person to person. **Bottom line:** If you are considering it, the reviews suggest it can work well for some people, but there is no guarantee. Your own response and the freshness of the bottle you receive may matter. Check the smell of a new bottle, since one long-term customer reports a recent decline.
Biohacker Summary
Members Only7 of 10 recommend it
Most of the panel recommends or uses vitamin C, with six of ten giving a latest position of recommends and one more saying he takes an extra gram a day. The most common reasons are collagen support for skin, joints and connective tissue, immune support, and antioxidant protection. Several pair it with collagen, one suggests taking it about an hour before a workout, and some prefer food sources or a liquid liposomal form. Doses people mention include 250 milligrams, 500 milligrams to 1 gram, about a gram a day split into divided doses, and 2 to 4 grams for inflammation. One panelist notes that the best dose is unclear and that high doses might blunt some of the benefits of exercise, and another stopped using 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.
- Is interested in the catalase enzyme as a potential addiction treatment protocol or enzyme, noting its effect on brain function related to alcohol addiction.
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.
- 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 that histamine intolerance arises primarily from a deficiency in the enzyme diamine oxidase (DAO) that breaks down histamine, which can be supplemented if necessary.
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.
- Explains that onion increases an enzyme called catalase, which helps get rid of hydrogen peroxide, a substance that bleaches hair and makes it look older and gray.
- Sauerkraut also contains vitamin C and beneficial bacteria that may support digestive health.
- Suggests consuming foods rich in catalase to slow the accumulation of hydrogen peroxide in the hair shaft, which can cause a bleaching effect.
- Mentions that diamine oxidase (DAO) is an enzyme located in the small intestine and kidney that helps dismantle and break down histamines, especially those from foods.
- When you’re low in zinc, you’ll have a lowered amount of specific antioxidants, including catalase.
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.
- Notes that gray hair follicles have low activity of catalase, an antioxidant enzyme that normally neutralizes hydrogen peroxide, contributing to oxidative stress.
- Recommends taking DAO (diamine oxidase) as a supplement to help metabolize histamine out of the body, especially if experiencing brain fog after eating certain foods, noting it can increase levels by up to 60%.
- Recommends a diamine oxidase (DAO) supplement as a last resort to help metabolize extra histamine, noting that studies show it can increase DAO in the body by 61%.
- Recommends taking DAO (diamine oxidase) as a supplement during periods when food causes extra inflammation, but advises against taking it all the time.
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.
- 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.
- Mentions catalase as how the body breaks down harmful hydrogen peroxide inside cells, which is an antioxidant system that weakens with age and needs support.
- Recommends supplementing with diamine oxidase as an initial step for mast cell stabilization.
- Explains that catalase can convert hydrogen peroxide into water in other parts of cells, but not in most mitochondria except the liver and heart.
- Cautions against taking exogenous catalase transmucosally, stating it's an important signaling molecule and playing with fire; he believes the body should upregulate its own production.
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 taking DAO (diamine oxidase) as a supplement before meals when food-derived histamine might be a problem, as it is an enzyme that degrades histamine in the gut.
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.
- The activity of catalase increased in supplemented participants' neutrophils, indicating enhanced neutrophil function.
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 4 for Digestion and Bloating
The ineffective grade rests on vitamin C, a 30 mg minor ingredient studied mostly inside bowel-cleansing drinks, while the main ingredients, diamine oxidase and catalase, have no human studies at all. So it is graded Tier 4, as the studies disagree.
- Emerging: not enough evidence to rank higher yet.
Where the evidence disagrees: 13 of the 23 human studies found no effect.
More Details
Members OnlyBody systems · Combine with · Possible side effects
Body systems: Digestive system
Combine with: For histamine-related digestive sensitivity, DAO is best taken 10-15 minutes before meals. It may pair well with quercetin and vitamin C, which help stabilize mast cells and support histamine metabolism, and with vitamin B6, copper, and magnesium, which act as cofactors for DAO and histamine pathways. If the real goal is fast post-meal upper-abdominal comfort, consider a broad-spectrum digestive enzyme blend with lipase, amylase, and protease, plus ginger or peppermint oil, and betaine HCl only if low stomach acid is suspected and no ulcer or reflux is present. Probiotic strains with low histamine production, such as Bifidobacterium infantis or Lactobacillus rhamnosus, may help gut balance. Consult a healthcare provider, especially if taking meds (bromelain) or if symptoms are persistent.
Possible side effects: No major side effects reported for this product. In one trial, a vitamin C bowel-cleansing drink was linked to more bloating, but that use is very different from this small dose.
Supplement Facts
Vitamin C 30 mg · Catalase 10 mg · DAO 4.2 mg
| Vitamin C | 30 mg | |
| Catalase | 10 mg | † |
| DAO | 4.2 mg | † |
Other ingredients: Microcrystalline Cellulose, Vegetarian capsule, Hypromellose, DRcaps, Silicon Dioxide.
Directions: Directions: Take one capsule 15 minutes before meals as needed.
Barcode (UPC) 850023777256 · Label source: NIH label database · Report a label change
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Graded November 4, 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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