Doxycycline is a generic prescription drug used to treat certain types of infections and other conditions. The drug comes as an oral tablet and oral capsule.

Doxycycline is prescribed to:

  • treat certain kinds of infections in adults and some children
  • help prevent malaria in adults and some children
  • treat severe acne in adults and some children
  • treat rosacea in adults

Doxycycline belongs to a group of drugs called tetracycline antibiotics.

This article describes the dosages of doxycycline, as well as its strengths and how to take it. To learn more about the drug, see this in-depth doxycycline article.

The following information describes dosages that are commonly used for doxycycline. But be sure to take the dosage your doctor prescribes for you. They’ll determine the best dosage to fit your needs. In some cases, your doctor may adjust your dosage from those mentioned here.

What are doxycycline’s forms?

Doxycycline is available as oral tablets and oral capsules. The drug comes in other forms as well, but this article covers these forms only. If you’re interested in other forms of the drug, talk with your doctor or pharmacist.

What strengths do doxycycline tablets and capsules come in?

Doxycycline oral tablets and capsules are available in the following strengths:

  • immediate-release tablets: 20 milligrams (mg), 50 mg, 75 mg, 100 mg, 150 mg
  • immediate-release capsules: 50 mg, 75 mg, 100 mg, 150 mg
  • delayed-release tablets: 50 mg, 60 mg, 75 mg, 80 mg, 100 mg, 150 mg, 200 mg
  • delayed-release capsules: 40 mg

Note: Immediate-release medications start working soon after you take a dose. Delayed-release drugs release their contents into your body slowly over time.

What are the usual dosages of doxycycline for adults?

The information below describes dosages that are commonly used or recommended. Your doctor will prescribe the doxycycline dosage that’s right for you based on certain factors, such as the condition the drug is being used to treat or prevent.

Be sure to take the dosage your doctor prescribes for you. In some cases, doctors may adjust your dosage from those shown below.

Dosage for infections

Both types of doxycycline tablets and the immediate-release capsules are used to treat certain types of infections, including:

The typical starting dosage of doxycycline for adults is 200 mg the first day. This is either taken as 100 mg every 12 hours or as 50 mg every 6 hours. After this, the maintenance (long-term) dosage is typically 100 mg per day. This may be taken once daily or in two divided doses of 50 mg every 12 hours.

The recommended maintenance dosage for more severe infections is 100 mg twice per day (every 12 hours).

Doctors typically prescribe doxycycline for 7 to 10 days to treat infections. But in some cases, they may prescribe it for longer periods of time.

For more information about your specific dosage, talk with your doctor.

Dosage for malaria prevention

The doxycycline delayed-release tablet is prescribed to help prevent malaria in adults. The typical dosage is 100 mg taken once daily.

Your doctor will recommend starting doxycycline treatment 1 to 2 days before you travel to the area where malaria may be present. Continue taking doxycycline daily during your travel and for 4 weeks after you leave the area.

Dosage for rosacea

To treat rosacea in adults, the typical dosage of the doxycycline delayed-release oral capsule is 40 mg taken once daily (in the morning) on an empty stomach.

What’s the dosage of doxycycline for children?

Doxycycline is used to treat or help prevent certain conditions in children ages 9 years and older.

Dosage for infections

To treat severe infections in children who weigh less than 45 kilograms (kg), or about 99 pounds (lb), the typical dosage is 2.2 mg per kg of body (mg/kg) weight taken every 12 hours. For reference, 1 kg is about 2.2 lb.

For children with less serious infections who weigh less than 45 kg, the dosage is 4.4 mg/kg of body weight for the first day of treatment. Then, the dosage is 2.2 mg/kg taken as a single daily dose or twice per day in divided doses.

The dosage to treat infections in children who weigh more than 45 kg is the same as the dosage used in adults. For details, see the “What are the usual dosages of doxycycline for adults?” section.

Dosage for malaria prevention

To prevent malaria, the typical dosage used in children is 2 mg/kg taken once daily up to the adult dose. Your child’s doctor will recommend starting doxycycline 1 to 2 days before traveling to the area where malaria may be present. This dose is continued throughout their travel to the area and for 4 weeks after leaving the area.

How to take doxycycline

It’s important to take doxycycline oral tablets or capsules exactly as prescribed by your doctor. Both the tablets and capsules should be taken with plenty of fluids. This helps prevent throat irritation and lowers the risk of ulcers from doxycycline.

Whether you can split or crush doxycycline depends on the form and strength you’re prescribed. You can ask your pharmacist if the strength and form of doxycycline you’re prescribed needs to be swallowed whole.

If you have trouble swallowing pills, talk with your doctor. You can also read this article for tips.

If you’re prescribed either the capsule form or the delayed-release tablets, you need to take your dose on an empty stomach (at least 1 hour before or 2 hours after a meal).

If you have other questions about how to take your dosage of doxycycline, talk with your doctor or pharmacist.

Is doxycycline used long term?

Whether doxycycline is used long term depends on the condition it’s being used to treat. For certain conditions, doxycycline may be used for several weeks or months. However, to treat certain types of infections, it’s typically used for 7 to 10 days.

If you have questions about how long you’ll take doxycycline, talk with your doctor to learn more.

Do not take more doxycycline than your doctor prescribes, as this can lead to harmful effects.

What to do in case you take too much doxycycline

Call your doctor right away if you think you’ve taken too much doxycycline. You can also call 800-222-1222 to reach America’s Poison Centers or use its online resource. But if you have severe symptoms, immediately call 911 (or your local emergency number) or go to the nearest emergency room.

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 another 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.