Highlights for minoxidil

  1. Minoxidil oral tablet is only available as a generic drug. It doesn’t have a brand-name version.
  2. Minoxidil comes as a tablet you take by mouth.
  3. Minoxidil is used to treat high blood pressure.

FDA warnings

  • This drug has black box warnings. A black box warning is the most serious warning from the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that may be dangerous.
  • Chest pain warning: Minoxidil can increase your heart rate and cause or worsen chest pain. Doctors usually prescribe a beta-adrenergic blocking drug with minoxidil to avoid this. If you have new or worsening pain in the chest, arm, or shoulders, tell your doctor right away.
  • Heart function warning: Minoxidil can cause poor heart function or worsen existing heart problems. Your doctor will monitor you for this. Doctors usually prescribe other medications, such as water pills (diuretics) and beta-adrenergic blocking drugs, with minoxidil to help prevent heart problems.
  • Proper usage warning: Minoxidil is a very strong blood pressure-lowering drug. Therefore, your doctor will only have you use minoxidil after you have tried the maximum dose of a diuretic (water pill) and at least two other blood pressure drugs at the same time, with no improvement in your high blood pressure. You should start minoxidil only when you are under close supervision of your doctor.
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Other warnings

  • Salt and water retention: Minoxidil can cause salt and water retention. This can lead to congestive heart failure. To avoid this, your doctor should prescribe a diuretic (water pill) for you to take with minoxidil. Talk to your doctor if you have swelling in your face, hands, ankles, or stomach, or if you gain 5 or more pounds rapidly.

Minoxidil is a prescription drug that’s only available in a generic form. It comes as an oral tablet.

Minoxidil may be taken as part of a combination therapy. It may be used with other drugs used to treat high blood pressure, or drugs used to reduce the side effects of minoxidil.

Doctors usually prescribe a beta-adrenergic blocking drug and a diuretic (water pill) to be taken with minoxidil. These drugs will help lower your blood pressure and reduce the side effects of minoxidil.

You should start minoxidil only when you are under close supervision of your doctor or at the hospital.

Why it’s used

Your doctor will only have you use minoxidil after you have used the maximum dose of a water pill (diuretic) and at least two other blood pressure drugs at the same time, and your high blood pressure has not gotten better.

How it works

Minoxidil belongs to a class of drugs called peripheral vasodilators. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.

Minoxidil works by relaxing and enlarging certain small blood vessels in your body so that blood flows through them more easily. This helps to reduce your blood pressure.

Minoxidil oral tablet doesn’t cause drowsiness, but it can cause other side effects.

More common side effects

The more common side effects that occur with minoxidil include:

  • nausea
  • vomiting
  • changes in facial and body hair, in both men and women (your hair may become darker and thicker, especially on your face and upper body)

If these effects are mild, they may disappear within a few days or a couple of weeks. If they’re more severe or don’t disappear, talk to your doctor or pharmacist.

Serious side effects

Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

  • increased heart rate
  • rapid weight gain of more than 5 pounds
  • trouble breathing, especially when you lie down
  • new or worsening pain in your chest, arms, or shoulders or a feeling of severe indigestion
  • dizziness, lightheadedness, or feeling faint

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.

Minoxidil oral tablet can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.

To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Examples of drugs that can cause interactions with minoxidil are listed below.

Guanethidine

Minoxidil can cause very low blood pressure if you take it with another blood pressure drug called guanethidine. Your doctor should stop your use of guanethidine several days before you start taking minoxidil. If your doctor feels that your use of guanethidine should not be stopped, you should be at the hospital while you take minoxidil for the first time.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.

This drug comes with several warnings.

Allergy warning

Minoxidil can cause a severe allergic reaction. Symptoms include:

  • trouble breathing
  • swelling of your throat or tongue
  • hives

Call 911 or go to the nearest emergency room if you develop these symptoms.

Don’t take this drug again if you have ever had an allergic reaction to it before. Taking it again could be fatal (cause death).

Warnings for people with certain health conditions

For people with an adrenal medulla tumor: Do not take minoxidil if you have an adrenal medulla tumor (pheochromocytoma). It may cause high blood pressure.

Warnings for other groups

For pregnant women: Minoxidil is a category C pregnancy drug. That means two things:

  1. Research in animals has shown adverse effects to the fetus when the mother takes the drug.
  2. There haven’t been enough studies done in humans to be certain how the drug might affect the fetus.

Talk to your doctor if you’re pregnant or planning to become pregnant. This drug should only be used if the potential benefit justifies the potential risk to the pregnancy.

For women who are breastfeeding: Minoxidil may pass into breast milk and can cause serious negative effects in a child who is breastfed. Tell your doctor if you are breastfeeding. A decision should be made to either stop breastfeeding or stop minoxidil.

For seniors: There are no specific recommendations for senior dosage. Older adults may process drugs more slowly. A normal adult dose may cause levels of the drug to be higher than normal. If you’re a senior, you may need a lower dose or you may need a different schedule.

All possible dosages and forms may not be included here. Your dose, form, and how often you take it will depend on:

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

Drug forms and strengths

Generic: Minoxidil

  • Form: oral tablet
  • Strengths: 2.5 mg and 10 mg

Dosage for high blood pressure (hypertension)

Adult dosage (ages 18–64 years)

  • The typical starting dosage is 5 mg, taken once per day.
  • Your doctor may increase your dosage to 10 mg, 20 mg, and then 40 mg, taken once or multiple times per day, as needed.
  • The maximum dosage is 100 mg once a day.
  • Your doctor will likely prescribe a beta-adrenergic blocking drug and a diuretic to be taken with the dose of minoxidil.

Child dosage (ages 12–17 years)

  • The typical starting dosage is 5 mg, taken once per day.
  • Your child’s doctor may increase their dosage to 10 mg, 20 mg, and then 40 mg, taken once or multiple times per day, as needed.
  • The maximum dosage is 100 mg once a day.
  • Your child’s doctor will likely prescribe a beta-adrenergic blocking drug and a diuretic to be taken with the dose of minoxidil.

Child dosage (ages 0–11 years)

  • The typical starting dosage is based on your child’s weight. It is 0.2 mg/kg, taken once per day.
  • The maximum dosage is 50 mg, once per day.

Senior dosage (ages 65 years and older)

Older adults may process drugs more slowly. A normal adult dose may cause levels of the drug to be higher than normal. You may need a lower dose or you may need a different schedule.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always speak with your doctor or pharmacist about dosages that are right for you.

Take as directed

Minoxidil is used for long-term drug treatment. It comes with serious risks if you don’t take it as prescribed.

If you don’t take it at all: Your high blood pressure may get worse. You will have a higher chance of a heart attack or stroke.

If you stop taking it suddenly: Your high blood pressure can rebound (get high again quickly). This may increase your chance for a heart attack or stroke. Do not stop taking minoxidil or any other high blood pressure medication without talking to your doctor.

If you don’t take it on schedule: Your high blood pressure may not get better or may get worse. You may not feel any different, but your blood pressure will not be well controlled. This can increase your chance for a stroke or heart attack.

If you miss doses: Wait until it is time for your next dose, then continue with your regular schedule.

If you take too much: If you take too much, your blood pressure can become dangerously low. Contact your doctor right away.

How to tell if the drug is working: You may not feel a difference after starting minoxidil, but your blood pressure will be better controlled. Be sure to take minoxidil exactly as prescribed. Your doctor can check your blood pressure to see how this drug is working.

Important considerations for taking minoxidil

Keep these considerations in mind if your doctor prescribes minoxidil for you.

General

  • You can cut or crush minoxidil tablets.

Storage

  • Store minoxidil at room temperature between 68°F (20°C) and 77°F (25°C).
  • Do not freeze minoxidil.
  • Keep it away from light.
  • Don’t store this medication in moist or damp areas, such as bathrooms.

Refills

A prescription for this medication is not refillable. You or your pharmacy will have to contact your doctor for a new prescription if you need this medication refilled.

Travel

When traveling with your medication:

  • Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
  • Don’t worry about airport X-ray machines. They can’t hurt your medication.
  • You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled box with you.
  • Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Self-management

You may need to buy a home blood pressure monitor to measure your blood pressure at home.

Clinical monitoring

Your doctor will test you every 6–12 months to make sure minoxidil is working for you. The following test will be done:

  • Electrolyte tests and body weight measurements. Minoxidil can cause salt and water to build up in your body. This can lead to congestive heart failure. Your doctor should prescribe that you take a diuretic with minoxidil to help prevent this.

The following tests may also be done, depending on your overall health when you started taking this drug:

  • A urine test. This makes sure you are getting rid of enough fluids to avoid heart failure.
  • A kidney function test. This makes sure your kidneys are functioning well.
  • Heart function tests. These include chest X-rays, echocardiography, and blood pressure tests.

Hidden costs

You may need to buy a home blood pressure monitor to measure your blood pressure at home.

Prior authorization

Many insurance companies require a prior authorization for this drug. This means your doctor will need to get approval from your insurance company before your insurance company will pay for the prescription.

Are there any alternatives?

There are other drugs available to treat your condition. Some may be better suited for you than others. Talk to your doctor about other drug options that may work for you.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.