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Prednisone Half-Life: When Will it Be Out of My System?

Prednisone Half-Life: When Will it Be Out of My System?

What is Prednisone’s Half-Life?

Prednisone’s half-life is 2-3 hours. It takes 2-3 hours for about half of your prednisone dose to leave your system.

What in the world is a half-life, and why does it matter when you’re taking prednisone? I’m Dr. Megan, the Prednisone Pharmacist, and I’m here to explain today what a prednisone half-life is and why you should care. First of all, when you might be looking up the term prednisone half-life, what are you really wanting to know? Scroll down to know more!


What is Prednisone’s Half-life?

The short answer is the half-life of prednisone is two to three hours. But what does that even mean?

What is a Half-Life?

A half-life is how long it takes for half of something to be gone. So if an atomic bomb goes off, how long will it take for half of the radiation to disappear? And they do calculations, using the term t1/2, to figure out all sorts of really fancy, scientific things.

What you really probably want to know is, when am I going to feel better?

When is it going to be out of my system?

And that’s the question we will answer in this article.

Prdnisone Half life

For example, if you took prednisone 40 milligrams, you took two of these. If you took that at 8:00 in the morning, it’ll take two to three hours for half of it to be gone out of your system.

So let’s just round it up to three. There are a lot of factors that could be changing how well your body breaks it down, but we’ll just round it up just for easy rounding sake.

So if it’s three hours and you took 40 milligrams, three hours after you take it, so from 8:00 until 11:00, you’ll be down to 20 milligrams.

Three hours after that, from 11:00 until 2:00, you’ll be down to 10 milligrams still active in your system. From 2:00 until 5:00, you’ll be down to five milligrams, and we’re getting smaller and smaller here, right?

But how many half-lives matter?

The Half-Life Calculation

When you’re calculating, it’s really only about five and a half half-lives that you need to count until you can say it’s pretty much close to zero.

So you could say after about 18 hours, somewhere, give or take, your body is free of the act of prednisone.

So what difference does that make? I took it in the morning, and 18 hours later, it’s gone. Well, it has a lot of things that can affect it. First of all, if you’re taking prednisone at 8:00 AM versus 8:00 PM, that changes how much is active in your system during different times of the day.

For example, if you are taking it and it’s causing side effects like insomnia, you would want to be taking it as early as could, like 5:00 or 6:00 in the morning even, so that it could wear off completely by the time you need to fall asleep at night. That can help you get more restful sleep.

When Should You Take Prednisone?

So that’s the first thing it can affect is the side effects, but what about when else could you take it?

Some doctors will prescribe prednisone to be taken every other day, so you take five milligrams on Monday, skip, take nothing on Tuesday, five milligrams on Wednesday, and that can be happening because of the half-life.

It’s giving your body a day off to hopefully help your adrenal glands recover. They haven’t really shown that it necessarily makes much of a difference, but it’s a strategy your doctor can use to help you cope and hopefully recover from taking prednisone.

How Long Does Prednisone Last?

Other things that are worth understanding is prednisone is a medium length of time drug, so it lasts two to three hours. Whereas methyl prednisone lasts less time, and then dexamethasone lasts way more time.

It lasts almost like a whole day, its half-life, so it takes a long time for the dexamethasone to get out of your system. Whereas hydrocortisone is often used when people are trying to get off of prednisone, and it’s got a way shorter half-life, so it needs to be taken multiple times a day.

You can usually reliably only have to take prednisone once a day, but hydrocortisone, since it only lasts a few hours, it needs to be taken, for example, right before breakfast, at lunch, and at dinner maybe, or it might be four times a day. It really depends on when you need it, and you work that out with your doctor.

how long prednisone last

How Long Does Prednisone Stay In Your System?

So, I promised the answer to the real question. If you’re asking,

“Well, what is prednisone’s half-life?”, the real question I think you’re asking is,

“When will it be out of my system?” And the real question behind that is,

“When am I going to feel better? There are so many side effects.”

The prednisone molecule is going to be out of your system in about a day, the drug itself, but the side effects aren’t necessarily gone in a day.

Prednisone Side Effects Like a Tornado

For example, let’s pretend like prednisone is a tornado. A tornado might be a great way to get rid of a building. If your disease is a building that you didn’t want anymore, it would be a great way to do it.

It just goes in and immediately that building is gone, but what about all the collateral damage? What about all the other buildings? Oh, and your landscaping, and all of the people and their things that could have been affected.

Those are the side effects. You didn’t want to just take out one building. I mean, you probably only wanted to take out one building, but it took out a whole city or a whole street or a lot more. It had all of this damage.

When the prednisone is out of your system, that’s like the tornado passed through town. It’s gone. The tornado’s no longer there, but its consequences are. There’s still all of that damage that isn’t disappearing anytime soon.

Somebody’s got to build those buildings back up. Somebody has to plant those trees again. Somebody has to find all of the things that blew away in the storm, and so prednisone side effects do not instantly go away.

prednisone side effects

Some of them might, like for example, hunger, It might suddenly just instantly be gone. You might just suddenly have your normal appetite back when you stopped taking it.

When Does Prednisone Anxiety Go Away?

But side effects like psychiatric ones–anxiety, and mood changes–might not go away very quickly, and why is this?

Because this is the actual drug itself in your system when it’s gone, but it changes things in your body, like the consequences to your brain, to your adrenal glands, to all over can be very long-term.

And for some people, it can take up to a year to really recover back to their formal adrenal-sufficient self.

Talk to your Doctor

talk to your doctor-prednisone

If you are feeling terrible after taking prednisone, then you need to talk to your doctor. You need to say, “Hey, I don’t feel so good. You took me off the prednisone, but I still need some help. Can you help me?”

You should definitely talk to your doctor about it because you shouldn’t feel awful after taking prednisone. You should be able to have the dose taken down slowly enough that you can recover. If you have any other real burning questions behind prednisone half-life, let me know below. I love to know what those are, so I can answer them in either comments or in a future video.

And if you need help recovering from prednisone, I have a prednisone checklist, and I will link that below that you can get. It has ways to cope with prednisone while you’re taking it and to help you recover after you’ve stopped taking it. Signing off as Dr. Megan, the Prednisone Pharmacist. And don’t forget to get your checklist by signing up below!

  • Free Prednisone Checklist

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  • 9+ Nutrients Depleted  by Prednisone
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