Minoxidil | Side Effects, Dosage, Uses & More

Generic Name:

minoxidil, Oral tablet

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  • Loniten (Discontinued)
A discontinued drug is a drug that has been taken off the market due to safety issues, shortage of raw materials, or low market demand.
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Highlights for minoxidil

Oral tablet
1

Minoxidil is used to treat high blood pressure.

2

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.

3

The most common side effects of using minoxidil include nausea, vomiting, and changes in body hair. Your hair may become darker and thicker, especially the hair on your face and upper body. This occurs in men and women.

4

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

5

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

IMPORTANT INFORMATION

FDA warning

This drug has a Black Box Warning. This is the most serious warning from the Food and Drug Administration (FDA). A black box warning alerts doctors and patients to potentially dangerous effects.

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, inform your doctor immediately.

Heart function warning. Minoxidil can cause poor heart function or worsen existing heart problems. Your doctor will monitor your for this. Doctors usually prescribe other medications, such as water pills (diuretics) and beta-adrenergic blocking drugs, with minoxidil to help prevent heart problems.

Since minoxidil is a very strong blood pressure-lowering drug, 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. You should start minoxidil only when you are under close supervision of the doctor.

Salt and water retention

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

Drug features

Minoxidil is a prescription drug that is only available in its generic form. It is an oral tablet. It may be taken as part of a combination therapy with other drugs used to treat high blood pressure or drugs used to reduce the side effects of minoxidil.

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 vasodilator. A class of drugs refers to drugs that work similarly. They are often used to treat similar conditions.

More Details

How it works

Minoxidil belongs to a class of drugs called peripheral vasodilator. A class of drugs refers to drugs that work similarly. They 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.

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minoxidil Side Effects

Oral tablet

Most Common Side Effects

The most common side effects that occur with minoxidil include:

  • Nausea

  • Vomiting

  • Changes in facial and body hair. Your hair may become darker and thicker, especially on your face and upper body. This occurs in men and women.

  • Rash

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

If you experience any of these serious side effects, call your doctor right away. If your symptoms are potentially life-threatening or if you think you’re experiencing a medical emergency, call 9-1-1.

  • Increased heart rate

  • Rapid weight gain of more than 5 lb

  • 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

Pharmacist's Advice
Healthline Pharmacist Editorial Team

Minoxidil does not cause drowsiness.

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.
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minoxidil May Interact with Other Medications

Oral tablet

Minoxidil can interact with other medications, herbs, or vitamins you might be taking. That’s why your doctor should manage all of your medications carefully. If you’re curious about how this drug might interact with something else you’re taking, talk to your doctor or pharmacist. Note: You can reduce your chances of drug interactions by having all of your prescriptions filled at the same pharmacy. That way, a pharmacist can check for possible drug interactions.

Medications that might interact with this drug

Other blood pressure drugs

Minoxidil can cause very low blood pressure when 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.

People with adrenal medulla tumor

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

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 fetus.

Women who are breast-feeding

Minoxidil may pass into breast milk and can cause serious adverse effects. 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 dosing. 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.

Allergies

Minoxidil can cause a severe allergic reaction. Symptoms include:

  • Trouble breathing
  • Swelling of your throat or tongue
  • Hives

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).

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How to Take minoxidil (Dosage)

Oral tablet

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

What are you taking this medication for?

High blood pressure (hypertension)
Form: Oral tablet
Strengths: 2.5 mg and 10 mg
Adult dosage (ages 18–64 years)
  • The starting dose is 5 mg, taken once per day.
  • Your doctor may increase your dose to 10 mg, 20 mg, and then 40 mg, taken once per day, as needed.
  • The maximum dose is 100 mg once a day.
  • Doctors usually prescribe that a beta-adrenergic blocking drug and a water pill (diuretic) be taken with the dose of minoxidil.
Child dosage (ages 0–12 years)
  • The starting dose is based on your child’s weight. It is 0.2 mg/kg, taken once per day.
  • The maximum dose is 50 mg, once per day.
Child dosage (ages 12–17 years)
  • The starting dose is 5 mg, taken once per day.
  • Your doctor may increase your dose to 10 mg, 20 mg, and then 40 mg, taken once per day, as needed.
  • The maximum dose is 100 mg once a day.
  • Doctors usually prescribe that a beta-adrenergic blocking drug and a water pill (diuretic) be taken with your dose of minoxidil.
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 to speak with your doctor or pharmacist about dosages that are right for you.
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Minoxidil comes with serious risks if you don't take it as prescribed.

If you don't take it at all

If you decide not to take this medication, 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

If you stop taking it suddenly, your high blood pressure can rebound. 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

If you forget to take your dose, 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 immediately.

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.

Minoxidil is a long-term drug treatment for high blood pressure.

Minoxidil must be stored at the right temperature

  • Store minoxidil at room temperature between 68°F (20°C) and 77°F (25°C).
  • Do not freeze minoxidil.
  • Keep it away from light.
  • Keep it away from high temperature.
  • Keep your drugs away from areas where they could get wet, such as bathrooms. Store these drugs away from moisture and damp locations.

Travel

When traveling with your medication:

  • Always carry your medication with you or 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.
  • Do not put this medicine in your glove compartment or leave it in the car, especially when the temperature is hot or freezing.

Self-management

You may need to buy a home blood pressure machine 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 water pill (diuretic) with minoxidil to help prevent this.

The following tests may 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 appropriately.
  • Heart function tests. These include chest x-ray exams, echocardiography, and blood pressure tests.

Hidden costs

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

Insurance

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 possible alternatives.

What does the pill look like?

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How Much Does minoxidil Cost?

Oral tablet

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Lowest price for minoxidil

Walmart $11.75
Sams Club $11.75
Kroger Pharmacy $16.29
These prices represent the lowest priced national pharmacies for minoxidil on GoodRx. They may be lower than your insurance.

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These prices represent the lowest priced national pharmacies for minoxidil on GoodRx. They may be lower than your insurance.

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Content developed in collaboration with University of Illinois-Chicago, Drug Information Group

Medically reviewed by Creighton University, Center for Drug Information and Evidence-Based Practice on September 3, 2015

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.
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