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Pronunciation: Kam-zai-ōs

Generic name: mavacamten
Dosage form: capsules (2.5mg, 5mg, 10mg, 15mg)
Drug class: Miscellaneous cardiovascular agents

Medically reviewed by Melisa Puckey, BPharm. Last updated on Aug 10, 2023.

What is Camzyos?

Camzyos (mavacamten) is used for obstructive hypertrophic cardiomyopathy (HCM) to improve shortness of breath and the ability to be active. Camzyos works by allowing your heart muscle to relax, which reduces the obstruction and improves overall heart function. Obstructive hypertrophic cardiomyopathy (HCM) occurs when the walls of the heart become excessively thickened, leading to an obstruction in the outflow of the left ventricle which reduces the heart's ability to pump blood effectively.

Camzyos is an allosteric and reversible inhibitor selective for cardiac myosin. Myosin is a protein in the heart muscle that is involved in making the heart muscle contract and relax. When Camzyos binds to myosin, the heart muscle relaxes more, so the heart fills with blood and is able to pump more effectively.

Camzyos became an FDA-approved medicine on April 28, 2022, for the treatment of adults with symptomatic New York Heart Association (NYHA) class II-III obstructive hypertrophic cardiomyopathy (HCM) to improve functional capacity and symptoms.


Camzyos may cause serious side effects, including:

Heart failure:

Heart failure is a condition where the heart cannot pump with enough force. Heart failure is a serious condition that can lead to death. You must have echocardiograms before you  take the first dose and also during your treatment with this medicine. This is important to help your healthcare provider understand how your heart is responding to this medicine. People who develop a serious infection or irregular heartbeat have a greater risk of heart failure during treatment.

Call your doctor at once if you have shortness of breath, chest pain, tiredness, swelling in your legs, rapid weight gain, or racing or pounding heartbeats.

The risk of heart failure is also increased when Camzyos is taken with certain other medicines. Tell your healthcare provider about the medicines you take, both prescribed and obtained over-the-counter, before and during treatment.

Because of the serious risk of heart failure, this medicine is only available through a restricted program called the Camzyos Risk Evaluation and Mitigation Strategy (REMS) Program.

See Camzyos side effects for information about side effects.

Before taking this medicine

Some drugs should not be used with Camzyos. Your treatment plan may change if you also use:

Tell your doctor if you have ever had:


Camzyos may harm an unborn baby. You may need a pregnancy test to make sure you are not pregnant for using this medicine. Use effective birth control while using this medicine and for at least 4 months after your last dose. Tell your doctor if you become pregnant.

Camzyos can make birth control pills less effective. Ask your doctor about other birth control options such as an injection, implant, skin patch, vaginal ring, condom, diaphragm, cervical cap, or contraceptive sponge.


Ask a doctor if it is safe to breastfeed while using Camzyos.

How should I take Camzyos?

  • Take Camzyos capsules exactly as your healthcare provider tells you to take it.
  • Do not change your dose without talking to your healthcare provider first.
  • Take Camzyos once a day.
  • Swallow the capsule whole. Do not break, open, or chew the capsule.
  • You will start with and initial dose and over weeks your Doctor will increase your dose depending how you respond to the medicine.
  • Your healthcare provider may change your dose, temporarily stop, or permanently stop your treatment if you have certain side effects.
  • If you miss a dose, take it as soon as possible and take your next dose at your regularly scheduled time the next day. Do not take 2 doses on the same day to make up for a missed dose.
  • If you take too much or overdose, call your healthcare provider or go to the nearest hospital emergency room right away.

Dosing information

Usual Adult Dosage for Hypertrophic Cardiomyopathy

Starting dose: 5 mg orally once a day

Allowable subsequent doses with titration: 2.5, 5, 10, or 15 mg orally once a day


  • Patients may develop heart failure while taking this drug; regular left ventricular ejection fraction (LVEF) and Valsalva left ventricular outflow tract (LVOT) gradient assessment is needed for careful titration to achieve an appropriate target Valsalva LVOT gradient, while maintaining LVEF at least 50% and avoiding heart failure symptoms.
  • When initiating or titrating this drug, LVEF should be considered first, then the Valsalva LVOT gradient and patient clinical status should be considered to guide appropriate dosing; the algorithms for INITIATION and MAINTENANCE should be followed for appropriate dosing and monitoring schedules.
  • If LVEF is less than 50% during therapy, this drug should be interrupted; the algorithm for INTERRUPTION should be followed for guidance on interrupting, restarting, or discontinuing this drug. If interrupted at 2.5 mg, the patient should either restart at 2.5 mg or permanently discontinue this drug.

Available Strengths 

  • 2.5mg, 5mg, 10mg, 15mg capsules.

Camzyos side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Camzyos may cause serious side effects. Call your doctor at once if you have:

  • heart failure symptoms eg shortness of breath, chest pain, tiredness, swelling in your legs, rapid weight gain, or racing or pounding heartbeats.

Common side effects of Camzyos may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Camzyos?

Tell your doctor about all your other medicines, especially:

  • Moderate to strong CYP2C19 inhibitors or strong CYP3A4 inhibitors
  • Moderate to strong CYP2C19 inducers or moderate to strong CYP3A4 inducers

This list is not complete. Other drugs may affect Camzyos, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Click on the link below to check for interactions with Camzyos.


Store at room temperature between 68°F to 77°F (20°C to 25°C).


Active ingredient: mavacamten

Inactive ingredients: croscarmellose sodium, hypromellose, magnesium stearate (non-bovine), mannitol, and silicon dioxide. The capsule contains black iron oxide, gelatin, red iron oxide, titanium dioxide, and yellow iron oxide.


Bristol-Myers Squibb Company, Princeton, NJ 08543 USA

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.