Ebselen is a drug that contains selenium and has anti-inflammatory and antioxidant properties. It may prevent and improve memory, arthritis, and cancer. But, did you know that it is currently being examined in clinical trials as a treatment for bipolar disorder? Keep reading to find out more about the uses, side effects, and dosage of ebselen.

Disclaimer: By writing this post, we are not recommending this drug. Some of our readers who were already taking the drug requested that we commission a post on it, and we are simply providing information that is available in the scientific and clinical literature. Please discuss your medications with your doctor.

What Is Ebselen?

Ebselen is a drug containing the element selenium [1].

It has multiple effects on the body, such as preventing inflammation and protecting cells against the harmful effects of oxidants [2].

Ebselen was initially tested as a treatment for stroke and is now under investigation in a clinical trial as a potential treatment for bipolar disorder [3, 4, 5].

Mechanism of Action

Oxidants (hydroxyl radicals and hydrogen peroxide) can damage proteins, fats, and DNA. This speeds up aging and leads to age-related diseases, including stroke, Parkinson’s and Alzheimer’s disease [2].

Ebselen blocks the activity of oxidants and reduces cell damage via multiple mechanisms, such as the following:

  • Mimics activity of an antioxidant enzyme (glutathione peroxidase): Ebselen converts harmful products made by oxidants back to harmless products (such as converting selenic acid to selenol). It also converts oxidants, such as hydrogen peroxide to water [2].
  • Prevents cell death (apoptosis) caused by injury or toxic exposure by blocking proteins involved in apoptosis (thiol groups) [2].
  • Crosses the blood-brain barrier and blocks an enzyme in the brain involved in the breakdown of acetylcholine (acetylcholinesterase), which may improve memory [2, 6].
  • Irreversibly blocks an enzyme involved in cell communication and growth (Inositol Monophosphatase) in a similar way to lithium (approved treatment for bipolar disorder) [4].
  • Prevents the spread of brain cancer cells (glioblastoma cells) by [7, 8]:
  • Decreasing the production of pro-inflammatory compounds (cytokines IL-6, IL-8)
  • Disrupting the cancer cells’ resistance to death
  • Blocks an enzyme that helps tumors survive (glutamate dehydrogenase).
  • Prevents iron overload in the heart, a major cause of heart failure [9].
  • Decreases production of proteins involved in Alzheimer’s disease (amyloid precursor protein and β-secretase) and reduces toxic protein accumulation (amyloid plaques) in the brain [10].
  • Increases serotonin production, which prevents the formation of tumors in the gut and affects mood [11].

Potential Uses of Ebselen

1) May Help with Stroke Recovery

In a study, 300 stroke patients were given either ebselen or placebo for 2-weeks. Ebselen greatly improved stroke symptoms compared to placebo after 1 month, if patients received it within 24 hours of the stroke [3].

In two other studies, ebselen reduced brain damage from a stroke (ischemic and hemorrhagic stroke)The effect was greater if the patients received ebselen within 6 hours of the stroke [12, 13].

In a study, 286 stroke patients received either ebselen or placebo for 2 weeks. Ebselen prevented brain damage from stroke 2 weeks, 1 month, and 3 months after treatment [12].

Intravenous ebselen decreased damage to gray and white matter in mice with stroke by reducing the damage caused by oxidants (free radical species) in the brain [14, 12].

In rabbits, ebselen protected the brain from damage when it was given shortly after stroke [15].

2) May Help With Bipolar Disorder

Lithium is an effective treatment for bipolar disorder but has unwanted side effects and can be toxic even with normal doses [4].

In the first study of 16 healthy participants, ebselen mimicked the effects of lithium in the brain (by reducing levels of an enzyme, Inositol Monophosphatase). It also increased the recognition of emotions like disgust and happiness, reduced impulsivity, and improved decision-making, all important for bipolar disorder [5].

In another study of 20 healthy participants, ebselen reduced the glutamate and the enzyme Inositol Monophosphatase in the brain in a similar way to lithium [16].

Ebselen increased the recognition of positive emotions and decreased impulsive behavior in a study on 20 healthy participants, highlighting its potential to be used for bipolar disorder [17].

3) May Prevent Noise-Induced Hearing Loss

In a study, 83 healthy adults received ebselen at 200 mg, 400 mg, and 600 mg or placebo twice daily for 4 days before listening to music for 4 hours. Ebselen prevented noise-induced hearing loss better than placebo, with the most effective dosage being 400 mg [18].

In rats, treatment with ebselen before and immediately after exposure to noise decreased the loss of sound-sensing cells of the ear and prevented hearing loss [19, 20].

4) May Reduce Impulsivity

Ebselen decreased impulsive actions during a gambling task in a study on 20 healthy participants. Ebselen-treated participants recognized positive emotions more than negative emotions, compared to placebo-treated participants, suggesting that ebselen may be used in impulsive and mood disorders [21].

5) May Improve Memory and Help With Alzheimer’s Disease

Ebselen shows potential both for the prevention and treatment of memory impairment diseases. In mice with symptoms of Alzheimer’s disease, ebselen improved learning and memory [22, 10].

An imbalance between the antioxidants and oxidants is another early marker of Alzheimer’s disease. Ebselen decreased oxidative stress in mice. It also decreased the production of toxic proteins in the brain (by reducing the compounds needed to make Aβ proteins) [10].

6) May Help With Arthritis

Ebselen decreased the movement of white blood cells (polymorphonuclear leukocytes, T-lymphocytes) to joints and reduce inflammation in rats. These effects can be beneficial in treating arthritis, where joint inflammation can cause serious damage [23, 24, 25].

7) May Help With Diabetes

Diabetes can lead to various complications, including hardening of arteries (atherosclerosis) and kidney damage [26].  

In mice with diabetes, ebselen protected against artery hardening and kidney damage by reducing oxidative stress [27, 28].

8) May Protect Against Osteoporosis

Osteoporosis is a disease where bones become fragile and more susceptible to damage.

In mice, ebselen reduced the breakdown of bone tissue by decreasing the production of cells that degrade bones [29].

9) May Help Fight Cancer

Ebselen reduced tumor growth by a remarkable 58% in mice with human pancreatic tumors [30].

In breast cancer cells, the use of ebselen and radiation therapy increased cancer cell death and stopped cancer progression [31].

Ebselen increased cancer cell death by increasing the production of harmful oxidants (reactive oxygen species). It also decreased tumor growth and invasion in kidney and pancreatic cancer cells [32, 30].

10) May Prevent Inflammation

Inflammation results in the production of harmful oxidants (free radicals) in the body. Since ebselen is an antioxidant, it can also help reduce inflammation [33].

Ebselen prevented fluid buildup in the lungs and reduce inflammation of the lungs and airways (bronchi) in rats and mice [34, 35, 36, 37].

It reduced inflammation in muscles and restored the function of small blood vessels in rats [38].

11) May Protect the Liver

Ebselen prevented liver injury caused by a bacterial toxin (staphylococcal enterotoxin B) by reducing inflammation and cell death in mice [39].

In multiple rat studies, ebselen prevented:

  • Alcohol-induced liver damage by reducing oxidative stress and inflammation [40].
  • Liver injury caused by activated liver immune cells (Kupffer cells) by decreasing the production of pro-inflammatory cytokines and oxidants [41, 42].
  • Bile acid-induced liver injury [43].

12) May Protect Male Reproductive Organs

Manganese Toxicity

Manganese increases sperm abnormalities and decreases sperm motility and count. It also reduces the levels of testosterone and luteinizing hormone.

In rats, ebselen reversed the toxic effects of manganese on male fertility, thus protecting male reproductive organs [44].

Cadmium Toxicity

Ebselen reduced cadmium-induced damage to testes in mice by decreasing oxidative stress [45].

13) May Prevent the Spread of Zika Virus

ZIKA virus infection increases oxidative stress and inflammation in mouse testes.

In mice, ebselen reduced oxidative stress and pro-inflammatory response in the testes. It also prevented the sexual spread of the ZIKA virus [46].

14) May Reduce Chemotherapy Side Effects

In rats, ebselen reduced toxicity in the kidneys caused by cisplatin, a type of chemotherapy. Cisplatin reduces the kidneys’ antioxidant defense, which ebselen helps to restore [47, 48].

15) May Protect Against Malaria

In human cells, ebselen blocked the growth of a mosquito species that causes malaria (Plasmodium falciparum) [49].

In rat cells, ebselen reduced the ability of a mosquito species to cause malaria in mice (P. berghei) [49].

16) May Help Fight Bacterial Infections

In roundworms, ebselen was effective in treating a drug-resistant bacterial infection (methicillin-resistant S. aureus) better than current antibiotics (vancomycin and linezolid). It also showed increased the effects of antibiotics, helping to combat the infection [50, 51].

17) May Help Fight Fungal Infections

Ebselen was effective in rapidly killing fungi within 2 hours of treatment, including [52]:

  • Candida
  • Cryptococcus, which can be especially dangerous in people with a very weak immune response

In fact, it was more effective than common antifungal drugs (fluconazole, flucytosine, and amphotericin) in killing fungi in roundworms [52].

18) May Help Fight Viruses

In cells, ebselen blocked the activity of the following viruses [53, 54]:

  • Herpes simplex type 1, which often causes cold sores (and more rarely genital herpes)
  • Hepatitis C
  • Vesicular stomatitis, which humans often contract from animals

19) May Preserve Stem Cells

Ebselen preserved the survival, shape, and function of stem cells in low temperatures by protecting them from harmful oxidants. It also improved stem cell function in human cornea tissues (the transparent part of the eye), indicating that ebselen is a useful preservative agent during cornea transplantations [55].

Side Effects

Ebselen is listed as a safe drug but without proven use by the National Institute of Health Clinical Collection [4].

Few patients in clinical trials reported drowsiness [21].

Most clinical studies did not report any side effects [56, 57, 14, 19].


Ebselen can break down skin pigments and reduce melanin in the body, which may increase the risk of cancer [58].

In yeast, ebselen may damage DNA and turn off genes that help reduce the damage [59].

High doses of ebselen can kill specific cells (HepG2 cells, hybridoma cells) [60].

Ebselen causes calcium release from the mitochondria, disrupting mitochondrial function. This results may result in loss of energy and quicker aging [2, 61, 62].

It can release zinc in the body, which reduces DNA repair [2].  

Drug Interactions

In rabbits, ebselen enhanced the activity of tissue plasminogen activator (tPA), the current treatment for stroke [63].

Ebselen contains selenium, which can interact with different medications in various ways, listed below [64]:

  • Selenium stimulates the immune system, so drugs such as corticosteroids that suppress the immune system should be avoided.
  • Selenium reduces blood clotting, so taking it with other anticoagulants like aspirin can increase bruising and bleeding.
  • Selenium taken with beta-carotene, Vitamin C, and Vitamin E may decrease the effectiveness of medications that lower cholesterol levels (statins and niacin).
  • Selenium may slow down how fast the body breaks down sedatives, increasing their effects and side effects.

Ebselen In Combination With Other Compounds

Ebselen and silver helped to overcome bacterial infections caused by drug-resistant bacteria [65].


The dose in patients with stroke was 150 mg of ebselen granules in water twice daily [12, 3].

For the prevention of hearing loss, patients were given 200 mg, 400 mg, or 600 mg twice daily [18].

Ebselen was administered as capsules at a total dose of 3600 mg in the span of 24 hours in clinical trials in healthy volunteers. This should not be taken as the therapeutic dose, as higher doses are used in healthy volunteers to investigate how safe the drug is and how it is metabolized in the body [16, 21].

Limitations and Caveats

Most studies on ebselen were done on animals.

There have been very few clinical trials performed to test this drug. They were small-scale and most have not moved past phase 1 or 2 of the drug development process [4, 18, 3, 5].

Although ebselen is a clinically safe drug, there is no real proof of use yet.

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