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Catalase Enzyme: Roles & Functions + Supplements

Written by | Last updated:
Puya Yazdi
Medically reviewed by
Puya Yazdi, MD | Written by | Last updated:

Catalase is produced by almost every living creature. It helps remove hydrogen peroxide, which can damage cells. This remarkable enzyme helps prevent aging and chronic conditions. On the other hand, catalase supplements have no science to back them up. Read on to learn about catalase roles and factors that increase/decrease it.

What Is Catalase?

Catalase is an enzyme, a protein made by a living organism to help facilitate a chemical reaction. Specifically, catalase is an incredibly important and diverse antioxidant enzyme. Despite its importance, few people have heard of catalase.

What Does It Do?

Catalase and Hydrogen Peroxide

Catalase’s main ‘job’ is to remove hydrogen peroxide (H2O2) by converting it into water and oxygen [1].

Hydrogen peroxide is produced during aerobic respiration, the process by which cells generate usable energy by breaking down glucose and oxygen. However, it is considered reactive and can damage just about every part of the cell – so, it’s necessary for cells to remove excess hydrogen peroxide [1].


Since hydrogen peroxide is a powerful oxidizing agent, catalase is considered one of the more important antioxidant enzymes [2].

It’s worth noting that more complex organisms – including humans – have evolved to rely on hydrogen peroxide to some degree. It can activate the immune system, and immune cells can kill bacteria by bombarding them with oxidants like hydrogen peroxide [1, 3, 4].

Catalase helps regulate these systems and ensure that the toxic by-products don’t do too much damage to cells, but, as with many aspects of biology, this is a ‘Goldilocks’ scenario – ideally, catalase prevents damage without interfering with important signaling processes [1].

Some types of catalase, particularly those found in mammals, can also help break down other potentially toxic compounds, like alcohol [1, 5].



  • May increase lifespan and reduce aging
  • May protect against cancer
  • May help prevent inflammatory bowel disease, diabetes, and Alzheimer’s disease


  • Studies in humans are mostly correlational – they hint at links, not causes
  • No evidence that catalase supplements actually affect catalase levels in the body

Where Is It Found?

Just about every living thing that comes in contact with oxygen, from bacteria to animals, produces some version of catalase [1].

Human catalase is produced by cells in every organ of the human body [6].

The liver and kidneys, which help the body remove toxins, produce a particularly high amount of catalase. Red blood cells also make a lot of the enzyme since their job is to transport oxygen, a process that generates a lot of hydrogen peroxide [6].

Within cells, catalase can be present in several different cellular compartments, such as the mitochondria (the powerhouse of the cell) and peroxisomes (cellular organelles that break down fatty acids and hydrogen peroxide) [7, 8].

Catalase Roles in Health and Disease

Please note: the beneficial roles of catalase as a naturally occurring enzyme may not translate to the benefits of catalase supplementation.

1) Longevity

Mice engineered to produce more catalase live about 20% longer than normal mice. Conversely, mice lacking catalase have shorter lifespans than normal [9, 10, 11, 4].

Notably, this effect depends on the location of catalase within the cell: catalase in mitochondria had these protective effects, but catalase in peroxisomes didn’t [9, 12+].

On the other hand, more catalase doesn’t increase lifespan in fruit flies, though it can make the flies slightly more resistant to stresses like high temperatures [13, 14].

Catalase can prevent some of the cellular damage that comes from aging in mice. This includes protecting cells of the heart, thymus, and reproductive organs. However, overactive catalase may have paradoxically aging effects in young mice, even though it’s protective in older ones [15, 16, 17, 12, 18].

Catalase can help prevent aging-related damage in animals, which may, in turn, increase lifespan. This link has not yet been investigated in humans.

2) Hair Greying

Studies have consistently shown that grey hair-growing follicles have lower levels of catalase and higher levels of oxidants like hydrogen peroxide [2, 19, 20, 21].

These data support the idea that lower levels of catalase in hair follicles are responsible, at least in part, for hair going grey.

However, there isn’t any evidence that taking catalase supplements actually changes catalase levels in hair follicles in a meaningful way. Companies making such claims have found themselves in legal trouble [22].

3) Protection Against Excessive Dietary Fat

Mice engineered to have higher catalase levels have less heart, muscle, and liver damage after being fed a high-fat diet. Other aspects, like the development of obesity, were not changed [23, 24, 25].

Normal mice fed a high-fat diet tend to produce more catalase, suggesting that this enzyme might be part of the natural response to excessive dietary fat [26].

4) Cancer

Very broadly speaking, catalase can protect cells from potential damage. This makes the role of catalase in cancer a bit paradoxical since it can protect healthy cells from cancer-causing mutations, but it can also protect cancer cells from drugs used for treatment [27, 28, 29, 30].

A study of 246 people with prostate, lung, and colon cancer found that early-stage tumors and metastases had low levels of catalase. However, more advanced tumors had high catalase levels, illustrating this paradox [28].

Some studies suggested a genetic variation in catalase – C-262T (rs1001179), which is associated with decreased catalase activity – may correlate with increased cancer rates [31, 32, 33].

However, the results haven’t been consistent between studies, with some finding no link between this genotype and cancer [31, 34, 32].

In mice, higher catalase levels can prevent the development of tumors. On the other hand, high catalase levels make tumor cells in dishes and tumors in mice more resistant to chemotherapy and other cancer-killing drugs [29, 27, 35, 30, 36, 37, 38].

Treatment strategies based on this have been proposed, such as therapies to reduce catalase levels in tumors, thus making them more susceptible to traditional treatment. These strategies have shown some promise in mice; however, there haven’t yet been studied in humans [7, 39].

Catalase may protect healthy cells from cancer-causing mutations, but it may also protect cancer cells from anticancer drugs. Further research should cast more light on the paradoxical roles of catalase in cancer development and treatment.

5) Inflammatory Bowel Disease

Several studies in humans and in mice have suggested a link between decreased levels of antioxidants like catalase and IBD (Crohn’s disease and ulcerative colitis) [40, 41, 42].

Prior to the 1980s, enemas using hydrogen peroxide – which is removed by catalase – were used to treat constipation. However, this practice was discontinued after reports that this could lead to colon inflammation, further supporting this link [40, 43].

An analysis including over 1,500 people found that the C-262T variation (rs1001179) near the catalase gene may be associated with IBD [44, 45].

6) Acatalasemia

Acatalasemia is a rare genetic condition specifically caused by the lack of a functional catalase gene [46, 47].

When accompanied by ulcers and tissue death in the mouth, the condition is also known as Takahara disease – although this has become rarer in recent years, likely due to better mouth hygiene practices [46].

Typically, acatalasemia is a fairly benign disease that doesn’t require treatment – however, it may predispose those affected to more serious conditions, like type 2 diabetes and atherosclerosis [46, 48, 49, 47, 50].

7) Vitiligo

Vitiligo is a skin condition characterized by patches of depigmented (very pale) skin. In a study comparing 10 people with vitiligo and 7 controls, people with vitiligo had lower catalase levels in their skin [51+].

Additionally, an SNP rs769217 linked to the catalase gene (that likely reduces the enzyme’s function) may be associated with developing vitiligo [46, 52, 53].

8) Diabetes

The link between diabetes and catalase is not a straightforward one.

Positive Roles

As mentioned above, the lack of functional catalase can predispose people to diabetes. Additionally, some genetic variations in the catalase gene are associated with higher diabetes rates [46].

In a study on mice, low blood catalase levels were associated with the development of diabetes [54].

In diabetic mice, injections with catalase helped prevent diabetic retinopathy – a complication of diabetes that affects the eyes. Increased catalase levels also protected heart cells from damage caused by diabetes in mice [55, 56].

Negative Roles

In studies including over 100 people with diabetes, catalase levels were higher in diabetic people. Furthermore, higher catalase levels were associated with an increased risk of diabetes-related complications [57, 58].

In one study on mice, high catalase levels in the pancreas accelerated the progression of diabetes [59].

The roles of catalase in diabetes are contradictory and not fully understood, but there’s more evidence of its protective effects. High levels in diabetic patients might be a defense mechanism.

9) Alzheimer’s Disease

Broadly speaking, increased levels of oxidative molecules like hydrogen peroxide are associated with the development of Alzheimer’s disease. However, the role of catalase isn’t totally clear.

Several studies analyzing catalase activity in the brain have found lower activity in brains from people with Alzheimer’s, but other studies have found no such correlation. This may be due in part to the small sample size of these studies [60, 61, 62, 63].

In a slightly larger study of 25 people with Alzheimer’s and 25 controls, blood catalase activity was higher in those with Alzheimer’s – though it’s not entirely clear whether measuring the enzyme in the blood is indicative of its activity in the brain [64].

A study of over 250 people found no association between the C-262T variant of the catalase gene and the risk of developing Alzheimer’s disease [46, 65].

In mice, increased catalase levels reduced the frequency of Alzheimer’s-associated plaques in the brain [66, 67].

Conversely, inhibiting catalase in brain cells in dishes made these cells more susceptible to Alzheimer’s-related damage [68].

Limitations and Caveats

Most of the studies examined catalase that the body is naturally producing, not supplements. There isn’t any scientific evidence that catalase supplements have any effect on catalase levels in the body.

Furthermore, many of the studies – particularly those in humans – are correlational; they only point to certain connections but don’t prove a causative role of catalase levels.

The studies that did experimentally change catalase levels were done in rodents. Results from animals should be extrapolated to humans with caution.

Factors That Increase Catalase

Catalase levels are a marker of antioxidant status. Low or high levels don’t necessarily indicate a problem if there are no symptoms or if your doctor tells you not to worry about it. Improving your catalase levels won’t necessarily improve antioxidant protection, but it can be used as a biomarker.

The following is a list of complementary approaches to improve antioxidant status that may also balance low catalase levels. Though studies suggest various dietary and lifestyle factors, additional large-scale studies are needed. Remember to talk to your doctor before making any major changes to your day-to-day routine.

Catalase levels naturally vary from person to person. This is affected by many factors, including genetic differences, age, and diet [69, 70].

Additionally, catalase levels can vary within a single individual – the body naturally makes less catalase as it ages, and as discussed above, different tissues in the body naturally make different amounts of catalase [6+].

Although diet can undoubtedly affect catalase levels, the data in humans are scarce. This is, at least in part, due to the difficulty of measuring catalase activity in people without being too invasive.

In rats, extracts from cruciferous vegetables – like broccoli and cabbage – increased the activity of catalase in the liver. Vitamin C and alpha-lipoic acid increased the activity of catalase in the liver of diabetic rats [71, 72, 73].

Catechins – molecules found in green tea – also increased liver catalase levels in rats [74].

On the other hand, a high-sugar diet decreased catalase levels in rats [75].

Catalase Inhibitors & Test

Studies in cells using pure enzymes have shown that flavonoids, vitamin C, and some catechins actually inhibit the activity of catalase, even though these compounds can increase catalase levels in animals [76, 77, 78].

Remember that various forms of catalase exist and that some bacteria also make this enzyme. So it could be that these plant-based antioxidants may kill some bacteria in the gut (or on the skin if applied topically) by inhibiting catalase [79].

For example, fluoride (added to toothpaste or water) can kill bacteria by inhibiting catalase [79].

In fact, the catalase test has been used for many years to identify different species of bacteria (aerotolerant strains of Clostridium don’t make catalase and Bacillus species do) [80].

Catalase Side Effects & Safety

Due to the lack of studies, it’s hard to say what the side effects or safety concerns might be.

Since catalase is present in just about every food we eat, it’s reasonable to suppose that consuming additional amounts of the enzyme probably won’t do much harm – but, as always, it’s best to consult your healthcare provider about your specific situation before supplementing.

Catalase Supplements

Catalase supplements have not been approved by the FDA for medical use. In general, regulatory bodies aren’t assuring the quality, safety, and efficacy of supplements. Speak with your doctor before supplementing.

Supplements that contain the enzyme are available. However, there isn’t any scientific evidence that these supplements actually affect catalase levels.

Despite this, catalase has found its way into numerous formulations on the market. Catalase-only products come in various forms: capsules, liquids, and powder.

More commonly, this enzyme is combined with other enzymes, nutrients, or herbs – depending on the intended health benefit.

Many supplements advertised for reversing hair greying also contain horsetail and saw palmetto or biotin and folic acid.

In other cases, catalase is combined with digestive enzymes and/or probiotics. These combinations are intended to support gut health.

Products claiming to offer protection against free radicals combine catalase with various vitamins, minerals, or plant-based antioxidants.

As with catalase-only supplements, the evidence to support the use of this enzyme in combination with any other substance is completely lacking.


Because catalase is not approved by the FDA for any condition, there is no official dose. Users and supplement manufacturers have established unofficial doses based on trial and error. Discuss with your doctor if catalase may be useful as a complementary approach in your case and which dose you should take.

Dosages for catalase supplements vary, but they typically contain 250-500 mg of the enzyme per serving.

Where to Buy Catalase


Catalase is a powerful antioxidant enzyme responsible for removing hydrogen peroxide. It can help protect cells, preventing damage related to aging and chronic conditions.

Despite many beneficial roles of catalase in the body, there isn’t any evidence that taking supplements with this enzyme will have the same effects.

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