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When Do Prednisone Side Effects Start?

When Do Prednisone Side Effects Start?

Tick tock, tick tock, tick tock! When do prednisone side effects start? Can we predict it? Is it based on your dosage?

When Do Prednisone Side Effects Start?

Prednisone side effects can start as soon as you have taken the first dose. Some side effects are a little more delayed. Read this article to find out the factors that affect when prednisone side effects start.

Check out this video explaining the answer to the question, “When do Prednisone 💊 side effects start? ⌛”

Watch now!

Is predicting prednisone side effects like telling time?

So prednisone side effects start immediately? Is it like looking at a clock and saying, “well, it’s three o’clock”? I can tell you exactly what time it is by looking at a clock.

Is that how prednisone side effects are?

Darn it, no.

I wish I could say, “You will experience insomnia at nine o’clock tonight.”

But I can’t because prednisone side effects are so dependent on you! …Your individual situation. When taking prednisone you should consider the following:

  1. DNA: your genetics
  2. Dose: how much prednisone you’re taking
  3. Duration: how long you’re taking Prednisone
  4. Indication: what you’re taking it for


First, timing of prednisone has to do with your genetics. Prednisone actually inserts itself into your DNA. Prednisone is a prescription drug that mimics a naturally occurring hormone in your body. So when your doctor is giving you prednisone, what they’re trying to do is trick your body into thinking you have an extra of this really important hormone called Cortisol.


How high of a dose of prednisone your doctor prescribes is critical to understanding when side effects start. The higher the dose, the more likely the greater number and severity of side effects. For example, the higher the dose, the worse the mood changes and dementia.

Duration: How Long You’ve been taking Prednisone

Another factor that we should consider is the duration that you’re on prednisone. This drug is a great help for us but it comes with a price and that is experiencing the horrible side effects that it gives. You may experience the short-term side effects or the long-term side effects…which are both undesirable!

For example, the longer you take prednisone, the more likely you are to have eye complications like glaucoma or cataracts.

Indication: What You’re Taking Prednisone for

What’s the reason you’re taking prednisone? Is it for your immune system? for pain relief? We should keep in mind that we are taking prednisone for a specific diagnosis and often the side effects can overlap with or worsen symptoms of that condition. It can be tricky to tell whether it’s a side effect or a new symptom of a disease.

For example, when I took prednisone, I took it for a bleeding disorder, which shows up with strange, painless bruises (ecchymoses) and little red dots (petechiae). But those are also possible side effects to prednisone! So it was tricky to tell whether my autoimmune condition was flaring or whether it was just a side effect of prednisone.

Reason why you're taking prednisone

When Do those Prednisone Side Effects Start?

Some of them start instantly; within hours of the first dose. Some of them are a little more delayed. I’ve got an article and video about short-term prednisone side effects, and I’ve got another article about long-term prednisone side effects. This is part of my Prednisone Timing Series so that you can understand a little bit of what to expect.

Watch the videos below!

Unpredictable Timing

Like I said, I can’t completely predict for you. I can’t tell when prednisone side effects start. I can tell you the trends, what the literature has shown.

Even One Dose Can Cause Prednisone Side Effects

The first thing to understand is there is no dose too low, nor time short enough, to say you won’t have side effects.

If your doctor told you, “Oh, you’re only on it for five days, you won’t have any side effects.” That’s wrong! That’s just completely wrong.

Any dose, just one dose is enough to give you side effects. You might not experience them, but then again, you might. It’s unpredictable.

How Soon do Prednisone Side Effects Start?

So what can you expect?

Short-Term Prednisone Side Effects

First of all, short-term: you can get anxiety, jitteriness, and insomnia. It’s as if you’re really stimulated; maybe even euphoria. Learn more about that in my short-term video and article above.

Long-Term Prednisone Side Effects

Then the long-term side effects don’t happen immediately, like your stereotypical moon face.

When does Moon Face (Prednisone Side Effect) Start?

Moon Face doesn’t usually start at the beginning. It usually is delayed a little bit. Moon face usually happens when you’ve been on prednisone for more than three weeks. It can happen sooner if you take a high dose, such as over 40 mg per day. The main principle to understand is that moon face from prednisone is worse the higher the dose. The fat deposits worsen the higher the dose.

When does Osteoporosis (Prednisone Side Effect) Start?

Osteoporosis starts in the first three months of therapy with prednisone and other glucocorticoids. The most pronounced bone loss happens within those first three months. One study showed a 27% loss in bone density within the first year of treatment. The higher the dose of prednisone, the greater the risk of osteoporosis.


Some side effects start immediately. Some side effects take more time.

Because you’re reading this article, it’s pretty safe to assume you’re taking prednisone, right?

I created the Prednisone Checklist to help you cope with the top 15 side effects of prednisone. I don’t want you to make the top seven mistakes that prednisone users make. So sign up and get it so you can avoid as much misery as possible and feel as empowered and successful as possible while you take prednisone.

Free Prednisone Checklist

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Dr. Megan Milne, PharmD, BCACP

Dr. Megan Milne, PharmD, BCACP, is an award-winning clinical pharmacist board certified in the types of conditions people take prednisone for. Dr. Megan had to take prednisone herself for an autoimmune condition so understands what it feels like to suffer prednisone side effects and made it her mission to counteract them as the Prednisone Pharmacist.

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