Corticosteroid Equivalence Calculator
Dexamethasone vs Prednisone Converter
This tool helps convert doses between dexamethasone and prednisone based on their relative potency. Dexamethasone is approximately 9-10 times more potent than prednisone on a milligram-for-milligram basis.
When doctors prescribe corticosteroids for inflammation or autoimmune conditions, two names come up again and again: dexamethasone and prednisone. Both work similarly-suppressing the immune system and reducing swelling-but they’re not interchangeable. Choosing between them isn’t just about which one is stronger; it’s about how long it lasts, what side effects you’re likely to get, and whether you’re treating a sudden flare-up or a long-term condition.
How Much Stronger Is Dexamethasone?
Dexamethasone isn’t just a little stronger than prednisone-it’s dramatically more potent. On a milligram-for-milligram basis, dexamethasone is about 9 to 10 times more powerful. That means if you take 1 mg of dexamethasone, you’re getting the same anti-inflammatory punch as 9 to 10 mg of prednisone. This isn’t theoretical. A 2020 study in Blood showed that dexamethasone triggered cell death in cancerous B-cells at much lower concentrations than prednisone. The reason? The dexamethasone-glucocorticoid receptor complex binds to DNA more tightly and stays attached longer, turning off inflammatory genes more effectively.
The National Adrenal Diseases Foundation rates prednisone’s potency at 5 (with hydrocortisone as 1), and dexamethasone’s at 25 to 50, depending on the body system. So if you’re treating severe swelling in the brain from a tumor, or nerve pain from cancer, dexamethasone’s strength makes it the go-to. A 1995 study cited by the American Academy of Family Physicians found dexamethasone improved pain relief in terminal cancer patients 35% more than prednisone.
Duration: One Dose vs. Five Days
Potency isn’t the only difference-duration matters just as much. Prednisone lasts about 12 to 36 hours in your body. Dexamethasone? It sticks around for 36 to 72 hours. That’s why dexamethasone is often given as a single dose or just one or two doses, while prednisone usually requires daily dosing for days or weeks.
This difference changed how we treat kids with asthma and croup. A 2006 study in the Journal of Pediatrics found that one dose of dexamethasone (0.6 mg/kg) worked better than five days of prednisolone for croup. Kids went back to the ER 24% less often. For asthma, a 2014 review in Pediatrics confirmed that two doses of dexamethasone were just as effective as a full five-day course of prednisone. That’s huge for parents trying to get their child to take medicine without daily battles.
Even in adults, this matters. A single 10 mg dose of dexamethasone delivers glucocorticoid exposure equal to five days of 60 mg prednisone. That’s why dexamethasone became a lifesaver during the COVID-19 pandemic. The RECOVERY Trial in 2020 showed that a 6 mg daily dose for 10 days cut death rates in hospitalized patients on oxygen by one-third. Prednisone wouldn’t have worked as well-its shorter half-life wouldn’t maintain consistent suppression of the cytokine storm.
Side Effects: Same Risks, Different Patterns
Both drugs can cause the same side effects: high blood sugar, mood swings, trouble sleeping, weight gain, bone thinning, and increased infection risk. The FDA gives both black box warnings for these dangers. But because dexamethasone is so much stronger and lasts longer, the way side effects show up can be different.
Here’s the twist: because you need less dexamethasone to get the same effect, you might actually get fewer side effects from the lower dose. But because it stays in your system longer, the effects can be more prolonged. A 2021 meta-analysis in Diabetes Care found that at equipotent doses, dexamethasone caused 18% more spikes in blood sugar than prednisone. That’s critical for diabetics or people at risk.
Psychiatric side effects also vary. A 2019 study in the Journal of Clinical Psychiatry tracked insomnia and mood changes in patients on both drugs. Insomnia hit 29% of dexamethasone users versus 22% on prednisone. Mood swings? 24% vs. 19%. And real-world data from Drugs.com backs this up: 37% of dexamethasone users reported trouble sleeping, compared to 29% on prednisone. Mood swings were reported by 33% vs. 26%.
On the flip side, prednisone users report more visible side effects. The same Drugs.com data showed 42% of prednisone users noticed “moon face” (facial swelling), compared to 31% on dexamethasone. Weight gain was reported by 58% of prednisone users versus 45% on dexamethasone. Why? Prednisone often requires higher total doses over longer periods. More total exposure = more fat redistribution and fluid retention.
When Do Doctors Choose One Over the Other?
It’s not about which is “better.” It’s about fit.
Dexamethasone shines in short-term, high-impact situations:
- Acute asthma attacks in children
- Croup (single dose works better than a 5-day course)
- Brain swelling from tumors or injury
- Severe allergic reactions
- COVID-19 pneumonia (as shown in the RECOVERY Trial)
Its long half-life means fewer doses, better compliance, and consistent drug levels. That’s why the Global Initiative for Asthma (GINA) guidelines now recommend dexamethasone as the preferred option for pediatric asthma exacerbations.
Prednisone is the standard for chronic conditions where you need to fine-tune the dose:
- Rheumatoid arthritis
- Lupus
- Chronic inflammatory bowel disease
- Polymyalgia rheumatica
The American College of Rheumatology still recommends prednisone for these because its shorter half-life lets doctors adjust daily. If a patient’s symptoms flare, you can bump the dose. If side effects creep in, you can drop it quickly. With dexamethasone, even a small daily dose lingers for days, making fine control harder.
Cost and Accessibility
On paper, prednisone is cheaper. A 30-tablet supply of generic 20 mg prednisone costs about $8.47. Dexamethasone 4 mg tablets run around $12.89. But here’s the catch: you need far less dexamethasone. For asthma, one 6 mg dose of dexamethasone replaces a 5-day course of 40 mg prednisone (200 mg total). So the actual cost per treatment is often similar.
And for hospital use? Dexamethasone is usually stocked because it’s more practical. One IV dose replaces multiple daily pills. That’s why it’s the default in ERs and ICUs.
What About Long-Term Use?
Neither drug is ideal for long-term therapy. The American Geriatrics Society’s 2022 Beers Criteria warns that corticosteroids above 7.5 mg prednisone-equivalent daily for more than three months are potentially inappropriate for older adults. Why? Bone loss, muscle wasting, diabetes, and infection risk pile up.
If you’re on either drug for months, your doctor should monitor your blood sugar, bone density, and infection signs. Switching from prednisone to dexamethasone for long-term use isn’t recommended-its long half-life makes it harder to taper safely. Prednisone’s shorter action gives you more control during withdrawal.
Bottom Line: It’s Not About Strength Alone
Dexamethasone is stronger and lasts longer. Prednisone is weaker but easier to control. The best choice depends on your condition, how long you need treatment, and what side effects you can tolerate.
For a sudden flare-asthma, croup, brain swelling, or severe infection-dexamethasone wins. One dose. Fast relief. Less hassle.
For chronic disease-arthritis, lupus, or inflammatory bowel disease-prednisone is still the go-to. Daily dosing lets you adjust. Easier to stop. Fewer lingering effects.
And if you’re worried about side effects? Talk to your doctor. Dexamethasone might mean less weight gain and facial swelling. But it might also mean more sleepless nights. Neither drug is harmless. But both, when used right, can be life-changing.
Is dexamethasone stronger than prednisone?
Yes, dexamethasone is about 9 to 10 times more potent than prednisone on a milligram-for-milligram basis. This means a much smaller dose of dexamethasone can produce the same anti-inflammatory effect as a larger dose of prednisone. For example, 0.75 mg of dexamethasone equals roughly 7.5 mg of prednisone.
Can I switch from prednisone to dexamethasone?
Switching is possible but must be done under medical supervision. Because dexamethasone is longer-acting and more potent, simply replacing prednisone dose-for-dose can lead to overdose or severe side effects. Doctors typically reduce the dose significantly-often by 80-90%-when switching to dexamethasone. This is common in hospital settings or for short-term use, but rarely done for long-term management.
Which one has fewer side effects?
It depends. Dexamethasone may cause less weight gain and facial swelling because lower doses are used. But it’s more likely to cause insomnia and mood swings due to its long half-life and stronger binding to brain receptors. Prednisone, taken at higher doses over longer periods, often leads to more visible side effects like moon face and fat redistribution. Neither is side-effect-free.
Why is dexamethasone used for COVID-19 but not prednisone?
Dexamethasone was proven in the 2020 RECOVERY Trial to reduce death rates in hospitalized COVID-19 patients on oxygen or ventilators. Its long half-life allows sustained suppression of the dangerous cytokine storm with once-daily dosing. Prednisone’s shorter duration would require multiple daily doses, which is less practical in critically ill patients and hasn’t been shown to have the same survival benefit.
Is dexamethasone safe for children?
Yes, dexamethasone is often preferred for children with asthma attacks or croup. A single dose is as effective as a five-day course of prednisone, improving compliance and reducing hospital readmissions. Studies show no significant increase in side effects like vomiting or behavioral changes compared to prednisone in pediatric use.
Can I stop taking dexamethasone suddenly?
No. Like all corticosteroids, dexamethasone suppresses your body’s natural cortisol production. Stopping suddenly can trigger adrenal crisis-low blood pressure, nausea, confusion, and even death. Tapering must be done slowly under medical supervision, especially after more than a few days of use. Even short courses can cause temporary suppression.