Serc (Betahistine)

1. What Is Serc?

Serc is a brand name for betahistine dihydrochloride, usually called betahistine.

It is a medication most often used in patients with Ménière’s disease.

Ménière’s disease is a disorder of the inner ear that can cause repeated attacks of:

• Vertigo (a spinning or moving sensation)
• Hearing loss that may come and go
• Tinnitus (ringing, buzzing, or other sounds heard in the ear)
• Pressure or fullness in the affected ear

Betahistine is mainly used to try to reduce the number or severity of vertigo attacks. It is generally used as a preventive treatment. It is taken regularly over time. It should not used to stop a severe vertigo attack once the attack has already started

*** It is important to understand that vertigo is a symptom, not a diagnosis. Many different conditions can cause vertigo, and betahistine is NOT the correct treatment for EVERY type of dizziness. Evidence mainly shows efficacy for Ménière’s disease. Unfortunately, betahistine is often prescribed for any patient with unclear or nonspecific vertigo. 

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2. How Does Betahistine Work?

Betahistine affects histamine, a natural chemical messenger found in the body.

Histamine is involved in many body functions, including the nervous system, blood vessels, allergies, and inflammation.

Betahistine acts on special proteins called histamine receptors. Receptors are structures on cells that respond to chemical signals.

H1 agonist and H3 antagonist

Betahistine mainly works on two types of histamine receptors.

• It acts as an H1 receptor agonist, which means that it activates H1 histamine receptors.

• It also acts as an H3 receptor antagonist, which means that it blocks H3 histamine receptors.

H3 receptors normally act somewhat like a brake on the release of histamine in the nervous system. By blocking these receptors, betahistine may allow more histamine to be released in areas of the brain involved in balance.

At the same time, its effect on H1 receptors may help widen very small blood vessels in the inner ear.

How could this help Ménière’s disease?

Ménière’s disease is associated with abnormal regulation of fluid within the inner ear, leading to fluid build-up and high pressures. You can read more about Menière's and endolymphatic hydrops here.

One theory is that betahistine may improve blood flow through the very small blood vessels that supply the inner ear. This may help the inner ear regulate its fluid environment more effectively, and reduce pressure.

Betahistine may also influence the way balance signals are processed in the brain.

The inner ears continuously send information about movement and balance to the brainstem. Betahistine may change activity in the vestibular nuclei, which are areas of the brainstem that receive and process this balance information.

In simple terms, betahistine may work in two main ways:

• By influencing blood flow and fluid regulation in the inner ear, reducing inner ear pressure
• By changing how balance information is processed in the brain

These effects provide a reasonable explanation for why betahistine might help some patients with Ménière’s disease.

However, understanding how a medication may work in the body does not automatically prove that it prevents vertigo attacks.

This is particularly important with betahistine because the biological explanation for how it works is stronger than the clinical evidence showing how much it actually helps patients.

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3. What Doses of Serc Are Available?

In Canada, Serc is commonly available as:

• 16 mg tablets
• 24 mg tablets

The usual total dose is between 24 mg and 48 mg per day.

The daily dose is usually divided into two or three doses.

Common examples include:

• 8 mg three times per day
• 16 mg three times per day
• 24 mg twice per day

The exact dose depends on the patient, their symptoms, and how well they tolerate the medication.

Betahistine can usually be taken with or without food. Taking it with food may reduce stomach upset.

What about higher doses?

Some doctors have used higher doses of betahistine, especially in patients with difficult-to-control Ménière’s disease.

For example, doses as high as 144 mg per day have been studied.

One major study, called the BEMED trial, compared:

• Placebo
• Betahistine 48 mg per day
• Betahistine 144 mg per day

A placebo is an inactive treatment used in research to determine whether a medication works better than no active medication.

The study found that vertigo attacks became less frequent in all three groups.

However, patients taking betahistine did not improve more than patients taking placebo.

Higher doses also did not clearly work better than standard doses.

For this reason, taking more betahistine does not automatically mean that it will work better.

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4. When Is Betahistine Used?

Ménière’s disease

The main reason betahistine is prescribed is to help control repeated vertigo attacks related to Ménière’s disease.

The goal is to reduce how often attacks occur or how severe they are.

Betahistine is usually taken regularly over time, in order to PREVENT an attack from happening.  It is not normally considered a fast-acting medication, so it should not be used for stopping an attack that is already happening.

Other types of vertigo

Betahistine is sometimes prescribed for other causes of vertigo.

However, the evidence is less clear.

This matters because not all vertigo has the same cause.

For example, one of the most common causes of vertigo is benign paroxysmal positional vertigo, usually called BPPV.

BPPV happens when tiny calcium crystals inside the inner ear move into the wrong part of the balance system. You can learn more about BPPV in this article.

It commonly causes brief spinning attacks when the head changes position.

The main treatment for BPPV is not medication such as Serc, but a repositioning maneuver, such as the Epley.

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5. Does Betahistine Actually Work?

This is one of the most important questions about Serc.

Betahistine has been prescribed around the world for many years.

Many patients report that they feel better while taking it.

However, scientific studies have not consistently shown that betahistine works better than placebo.

The evidence is therefore mixed.

Earlier studies

Some older studies suggested that betahistine could reduce vertigo.

However, many of these studies had important limitations.

For example:

• Some included only a small number of patients
• Different studies included different causes of dizziness
• Different studies measured improvement in different ways
• Some older studies were not designed as carefully as modern clinical trials

Because of these problems, it is difficult to know how much confidence to place in some of the earlier results.

The BEMED study

One of the most important studies of betahistine was the BEMED trial.

It was published in the British Medical Journal in 2016.

The study included 221 patients with definite Ménière’s disease.

Patients received:

• Placebo
• Betahistine 48 mg per day
• Betahistine 144 mg per day

They were treated for nine months.

Vertigo attacks became less frequent over time in all three groups.

However, there was no important difference between the placebo group and either betahistine group.

In simple terms:

Patients taking betahistine improved, but patients taking placebo improved by a similar amount.

This is especially important in Ménière’s disease because symptoms naturally change over time.

Patients may have periods with frequent attacks followed by long periods with very few attacks.

So, if someone starts betahistine and then improves, it does not always mean that the medication caused the improvement.

What do larger reviews show?

A systematic review is a scientific study that collects and evaluates the results of many studies on the same topic.

A review published in 2021 looked specifically at betahistine in Ménière’s disease.

The authors found that available research did not clearly show that betahistine worked better than placebo for controlling vertigo.

There was also no strong evidence that betahistine clearly improved:

• Hearing
• Tinnitus
• Quality of life

This does not mean that betahistine never helps anyone.

It means that researchers have not clearly proven that it provides a reliable benefit compared with placebo.

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6. Why Do Doctors Still Prescribe Betahistine?

There are several reasons.

First, betahistine is generally safe and well tolerated.

Second, Ménière’s disease is difficult to study because symptoms naturally come and go.

Third, some patients report significant improvement after starting treatment.

In an individual patient, however, it may be difficult to know whether improvement is due to:

• Betahistine
• The natural course of Ménière’s disease
• Other treatments
• Lifestyle changes
• A placebo effect

A placebo effect means that symptoms improve after treatment even when the treatment itself does not have a specific effect on the disease.

Because betahistine is generally safe and may help some patients, clinical guidelines still consider it a reasonable treatment option for Ménière’s disease.

However, patients should understand that its effectiveness has not been firmly proven.

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7. Does Betahistine Improve Hearing or Tinnitus?

Hearing

There is no strong evidence that betahistine restores hearing or prevents hearing loss caused by Ménière’s disease.

Some patients with Ménière’s disease have fluctuating hearing loss, meaning their hearing may improve and worsen over time.

This can happen whether or not they are taking betahistine.

Tinnitus

There is also no strong evidence that betahistine reliably improves tinnitus.

Tinnitus means hearing a sound when there is no outside sound producing it. You can learn more about tinnitus here.

Tinnitus may continue even when vertigo attacks are well controlled.

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8. Getting the Diagnosis Right

One of the most important parts of treating vertigo is determining what is causing it.

There is no single medication that treats every type of dizziness or vertigo.

If you were prescribed Serc for a condition other than Ménière's disease, such as "labyrinthitis" or any other type of non specific dizziness that has not been formally diagnosed, there is minimal evidence showing any efficacy in helping your symptoms. 

A proper assessment usually begins with a detailed discussion of the symptoms and a physical examination.

A hearing test is particularly important when Ménière’s disease is suspected because hearing changes are part of the condition.

Additional balance tests, imaging such as an MRI, or blood tests may occasionally be required if the diagnosis is unclear or another condition is suspected.

For a more detailed discussion of how vertigo is investigated, please see our article on vertigo.

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9. Side Effects of Betahistine

Betahistine is usually well tolerated.

The most common side effects include:

• Nausea
• Indigestion
• Stomach discomfort
• Headache

Taking betahistine with food may help reduce stomach symptoms.

Serious allergic reactions are uncommon but possible. Seek medical attention in that event.

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10. Who Should Not Take Serc?

Betahistine may not be appropriate for everyone.

It should not be used in people who are allergic to betahistine.

Betahistine may also require caution in patients with:

• Asthma, a condition that causes narrowing and inflammation of the breathing tubes
• A current or previous stomach ulcer

Patients who are pregnant, planning pregnancy, or breastfeeding should discuss betahistine with their doctor because safety information is limited.

Betahistine is also not routinely recommended for children because there is limited information about its safety and effectiveness in younger patients.

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11. Drug Interactions

Betahistine can interact with certain medications.

Patients should tell their doctor and pharmacist about all prescription medications, over-the-counter medications, vitamins, and supplements they are taking before starting Serc.

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12. How Long Should Betahistine Be Tried?

There is no single correct treatment length for every patient.

Betahistine is usually used as a preventive medication.

Taking it for only a few days may not be enough to determine whether it is helping.

In many cases, the response is evaluated over several weeks or months.

Keeping a vertigo diary

A vertigo diary can be very useful.

Patients can record:

• The date of each attack
• How long the attack lasted
• How severe it was
• Whether hearing changed
• Whether tinnitus changed
• Whether there was pressure in the ear
• Whether additional medication was needed

The important question is not simply:

“Do I feel better?”

The more useful question is:

“Are my vertigo attacks clearly becoming less frequent, shorter, or less severe?”

If the medication does not appear to be helping, the need to continue it should be discussed with the treating physician.

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13. Can Betahistine Be Stopped?

In most patients, betahistine does not need to be taken forever.

If vertigo has been well controlled for a long period, your doctor may eventually suggest reducing or stopping the medication.

This decision depends on:

• The diagnosis
• How long the patient has been stable
• How severe previous attacks were
• Other treatments being used
• The patient’s overall medical situation

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14. Conclusion

Serc, or betahistine, is a medication commonly used to help prevent vertigo attacks in people with Ménière’s disease.

It affects the histamine system and may influence blood flow, fluid regulation in the inner ear, and the way balance information is processed in the brain.

It is generally safe and well tolerated.

However, the scientific evidence is not as strong as many patients may expect.

The best large clinical studies have not clearly shown that betahistine prevents Ménière’s vertigo attacks better than placebo.

This does not mean that no patient can benefit from it.

It means that the benefit is uncertain and should be assessed carefully in each patient.

The most important part of treating recurrent vertigo is making the correct diagnosis.

Patients with repeated vertigo, hearing changes, tinnitus, or pressure in one ear should be properly assessed, including a hearing test when appropriate.

An ENT physician, particularly one with experience in hearing and balance disorders, can help determine the cause of the symptoms and decide whether betahistine or another treatment is appropriate.

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References

1. BGP Pharma ULC. SERC (betahistine dihydrochloride) Product Monograph. Health Canada. Revised March 25, 2026.

https://pdf.hres.ca/dpd_pm/00083994.PDF

1. Adrion C, Fischer CS, Wagner J, Gurkov R, Mansmann U, Strupp M, et al. Efficacy and safety of betahistine treatment in patients with Meniere’s disease: primary results of a long-term, multicentre, double-blind, randomised, placebo-controlled, dose-defining trial (BEMED trial). BMJ. 2016;352.

https://www.bmj.com/content/352/bmj.h6816

1. Van Esch B, van der Zaag-Loonen HJ, Bruintjes TD, van Benthem PPG. Betahistine in Meniere’s disease or syndrome: a systematic review. Audiology and Neurotology. 2022;27(1):1-33.

https://pubmed.ncbi.nlm.nih.gov/34233329/

1. Murdin L, Hussain K, Schilder AGM. Betahistine for symptoms of vertigo. Cochrane Database of Systematic Reviews. 2016;6.

https://pubmed.ncbi.nlm.nih.gov/27327415/

1. Basura GJ, Adams ME, Monfared A, Schwartz SR, Antonelli PJ, Burkard R, et al. Clinical Practice Guideline: Meniere’s Disease. Otolaryngology-Head and Neck Surgery. 2020;162(2 Suppl).

https://pubmed.ncbi.nlm.nih.gov/32267799/