Catalase is produced by almost every living creature. It helps remove hydrogen peroxide, which can damage cells. Read on to learn how this remarkable enzyme might help slow aging and prevent diseases like cancer – and how catalase supplements have no science to back them up.

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 enzymeDespite its importance, few people have heard of this enzyme.

What Does Catalase Do?

Catalase and Hydrogen Peroxide

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

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

Why Is Catalase Important?

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

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 [R+, R, R].

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 [R+].

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

Where Is Catalase Found?

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

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

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 [R+].

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) [R+, R+].

Snapshot of Catalase


  • 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

Health Benefits

1) Increasing Lifespan and Preventing Aging

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

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 [R, R+].

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 [R, R].

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 [R, R, R, R+, R].

To sum it up, 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) Stopping Hair Greying

Several studies have compared human hair follicles growing grey hair to those growing regular. These studies have consistently shown that grey hair-growing follicles have lower levels of catalase and higher levels of oxidants like hydrogen peroxide [R+, R, R, R].

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 [R*].

3) Protecting Against Damage Caused By Dietary Fat

Mice engineered to have higher catalase levels have less heart, muscle, and liver damage after being fed a high-fat diet, although other aspects, like the development of obesity, weren’t changed [R, R, R].

Normal mice fed a high-fat diet tend to produce more catalase, suggesting that this enzyme might be part of the natural response to the damage a diet with a lot of fat can cause [R].

4) Cancer and Chemotherapy Side Effects

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 [R+, R, R, R].

A study of 246 people with prostate, lung, and colon cancer found that early stage tumors had low levels of catalase. Metastases – when tumor cells spread and start growing in other organs – also had low catalase levels. However, more advanced tumors had high catalase levels, illustrating this paradox [R].

Studies of thousands of people suggested a genetic variation in catalase – a SNP before the start of the gene (in the promoter, the region of DNA that helps control how much of a gene is made) called C-262T (rs1001179), which is associated with decreased catalase activity – may lead to an increased risk of cancer [R+, R, R].

However, the results haven’t been consistent between studies, with some finding no link between this genotype and cancer risk [R+, R, R].

Analyses on whether this variation has any prognostic value for predicting survival in people with cancer have been similarly mixed: some studies have found associations, but others haven’t [R, R].

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 [R, R+, R, R, R, R, R+].

Treatment strategies based on this have been proposed, such as therapies to reduce catalase levels in tumor, thus making them more susceptible to traditional treatment. These strategies have shown some promise in mice; however, there haven’t yet been studies in people [R+, R].

In mice, higher levels of catalase protected muscles from damage caused by a common chemotherapeutic drug [R].

5) Inflammatory Bowel Disease

Several studies in humans and in mice have suggested a link between decreased levels of antioxidants, like catalase, and inflammatory bowel disease (Crohn’s disease and ulcerative colitis) [R+, R, R].

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 [R+, R].

An analysis including over 1,500 people found that the C-262T variation (rs1001179) near the catalase gene increases the risk of developing inflammatory bowel disease [R, R].

6) Acatalasemia

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

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 [R+].

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 hardening of the arteries, which can increase the risk of heart attacks and strokes [R+, R, R, R, R].

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 [R+].

Additionally, a SNP (rs769217 in the protein-coding region) linked to the catalase gene that likely reduces the enzyme’s function is associated with developing vitiligo [R+, R, R].

8) Diabetes

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

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 [R, R].

As mentioned above, a lack of functional catalase can predispose people to diabetes. Additionally, some genetic variations in the catalase gene are associated with an increased risk of developing diabetes [R+].

In one study in mice, high catalase levels in the pancreas accelerated the progression of diabetes. However, in another study, low blood catalase levels were associated with the development of diabetes [R, R].

Yet another study found that mice lacking catalase developed diabetes-like symptoms [R].

On the other hand, administering catalase was actually beneficial in animals with diabetes.

In diabetic mice, injections with catalase helped prevent diabetic retinopathy – a complication of diabetes that affects the eyes [R+].

Increased catalase levels also protected heart cells from damage caused by diabetes in mice [R].

What does this all mean?

The Bottom Line

All in all, the data on catalase in diabetes is a little contradictory – lower levels predispose to diabetes, but diabetic people tend to have more catalase activity.

It’s possible that the changes that occur during diabetes lead the body to produce more catalase to try to compensate. People with diabetes may also have a less functional catalase.

But since the studies in humans are only measuring correlations, it’s hard to say with certainty whether altered catalase levels help cause diabetes or the other way around.

9) Alzheimer’s Disease

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

Several studies analyzing catalase activity in the brain have found less catalase 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 – generally only around 10 [R, R, R, R].

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 [R].

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 [R+, R].

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

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

How to Boost Catalase

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

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 [R+].

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

In a study including 82 healthy volunteers, an extract from ginseng had no effect on catalase levels in the blood [R].

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 in diabetic rats [R, R+, R].

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

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

In short, a diet that’s relatively high in vegetables and low in sugar may promote catalase activity – and a glass of tea now and then might help, too.

Catalase Inhibitors & Catalase 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 [R, R, R].

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 [R].

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

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) [R].

Catalase Supplements

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.


Dosages for catalase supplements vary, but they typically contain 250 – 500 mg of the enzyme. Again, though, there’s no data on what effects such supplements have.

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.

Limitations and Caveats

Most of the studies discussed above examined catalase that the body is already producing naturally, not supplements. Once more for the folks in the back, 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, showing associations between catalase activity and various health and disease factors. It’s important not to assume that one thing causes something else just because the two are correlated.

The studies that did experimentally change catalase levels were done in rodents and used more invasive approaches – i.e. genetic engineering – to alter the levels of this enzyme. Rodents and humans are different, so results from animals should only be extrapolated to humans with caution.


Reviews of catalase supplements – primarily those that are marketed for the treatment of greying hair–are decidedly mixed. While a few users do report that such supplements worked for them, just as many, if not more, say that the product had no effect on keeping their hair from greying.

Buy Catalase Supplements


Catalase is a powerful antioxidant enzyme that’s responsible for removing hydrogen peroxide. This enzyme can help protect cells, preventing damage related to aging as well as diseases like cancer.

Although there’s a fair amount of evidence for many of the health benefits of catalase, there isn’t any evidence that taking supplements with this enzyme will have any effect whatsoever.

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