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What to know about taking prednisone: How long does it take to work?

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What is it?How long it takesSide effectsWhat to expectStopping prednisoneSummary
Prednisone helps treat inflammation, but there can be various side effects depending on your dose and how long you take it. It’s generally fast-acting, getting to work within 1–2 hours.
Medically reviewed by Philip Ngo, PharmD
Written by Lily Frew
Updated on

If you’ve ever had an arthritis flare or come into contact with poison ivy, chances are that you’ve had experience with prednisone and that it provided fast relief.

But while it’s an effective medication, there can be some negative side effects, particularly if you take it for a long period of time.

As prednisone can take effect quickly, you may notice improvements in a matter of hours, but might not experience the full benefits for a few days.

Knowing more about prednisone, how it works, and its possible effects can help you feel confident in your medication.

What is prednisone?

An older woman sitting down taking a prednisone pill, wondering how long it will take to work.

Prednisone is a generic medication that is a type of steroid that helps treat a range of conditions, particularly those related to inflammation.

According to the Centers for Disease Control and Prevention (CDC), it’s a first-line treatment for lupus, and doctors also use it to treat multiple sclerosis and the inflammatory effects of some cancers.

Its anti-inflammatory effects can also be helpful for allergic conditions like eczema and asthma and inflammatory conditions like Crohn’s disease and arthritis. The drug lowers your body’s immune system activity, which, in turn, helps reduce symptoms like inflammation and itching.

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How long does it take for prednisone to work?

One of the main benefits of prednisone is that it’s fast-acting. According to the American College of Rheumatology, the medication can get to work 1–2 hours after taking it. But you might not see the full effects until around 1–4 days afterward.

There is also a delayed-release oral version of prednisone available under the brand name Rayos. It releases the drug around 4 hours after taking it.

What are some of the side effects of prednisone?

While this medication can have many benefits, it does have side effects. These will depend on the dose and how long you take it. The risk becomes higher with a higher dosage of 40 milligrams per day or more and long-term usage. Some of the most common side effects include:

  • weight gain
  • gastrointestinal issues like nausea or diarrhea
  • mood changes
  • insomnia

Prednisone can also trigger or worsen certain conditions, such as:

  • osteoporosis
  • high blood pressure (hypertension)
  • high blood sugar

There’s no limit on how long you can take prednisone. It depends on the condition you’re treating and the dosage. But if you’re likely to take the medication long term, be aware of side effects and speak with a doctor if you have any concerns.

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What can you expect when taking prednisone?

Prednisone works fast, so you’ll probably get some relief from your symptoms right away, depending on your condition. If you’re taking it to treat an allergic reaction, you can expect quick relief from any uncomfortable itching you might be feeling.

Some mild side effects may begin to appear within the first week of taking it. You may be able to avoid these by:

  • Taking prednisone with food: This will help you avoid gastrointestinal symptoms.
  • Trying a low salt diet: This can help prevent some of the fluid retention and swelling associated with prednisone.
  • Taking your whole dose when you wake up: Prednisone can make you feel jittery, which can lead to insomnia. If possible, taking it early in your day can help ease those symptoms by bedtime.
  • Eating a balanced diet: That means plenty of fruits, veggies, whole grains, and reduced-fat milk and cheeses. This will help you stay at a moderate weight and prevent high blood sugar, which can sometimes happen when you take prednisone.

If you’re taking prednisone for only a week or two, the prescribing doctor will most likely start you on a high dose and then gradually lower it to minimize side effects. This is known as tapering.

But if you have symptoms, talk with the doctor about dropping your dose even more.

If you’re taking prednisone for more than a couple of weeks, long-term side effects can start to appear.

Some things to be aware of include:

  • Infections: Prednisone suppresses your immune system, so you’re at a higher risk of infection. Look out for symptoms of flu or sores that don’t heal.
  • Cataracts: Long-term prednisone use raises the risk of developing cataracts (clouding of the eye) that can affect vision. Regular eye exams are important.
  • High blood sugar: Since prednisone may raise your blood sugar, it can increase the risk of developing or worsening type 2 diabetes. You can speak with a doctor about checking your blood sugar.
  • Osteoporosis: Due to the risk of osteoporosis, you’re more likely to experience a bone fracture. You can speak with a doctor about bone density screening and starting osteoporosis treatment if necessary.

How do I stop taking prednisone?

If you need to stop taking this medication — due to side effects or you’re pregnant, for example — it’s important to talk with a doctor as you may experience withdrawal symptoms like fatigue, weakness, and pain.

You can usually stop short-term prednisone treatment immediately, but you should speak with a doctor before doing so to avoid any risks. If you’ve been taking it for longer, you might need to slowly taper off the medication to avoid withdrawal symptoms.

A doctor can talk with you about how to taper off prednisone. Experts agree that it should be gradual — it may start fast and slow down as you proceed through lower doses. If you experience any negative effects, you can return to your initial dosage and then follow a slower tapering schedule.

There is no universal tapering regimen, so this guidance could vary between healthcare professionals.


Depending on your particular condition, you may benefit greatly from taking prednisone. One of the main advantages of prednisone is how quickly it works. You can notice some improvements to symptoms almost straight away, and you’re likely to receive the full benefits within a week.

It is important to be aware of possible short- and long-term side effects and alert a healthcare professional immediately if you have any concerns.

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