Steroid Dose Converter
Dexamethasone is 9-10 times more potent than prednisone. One milligram of dexamethasone equals approximately 9-10 milligrams of prednisone. Use this tool to calculate equivalent doses based on your medication needs.
Dose Conversion Calculator
This is where the equivalent dose will appear.
When doctors prescribe steroids for inflammation or autoimmune issues, two names come up more than any others: dexamethasone and prednisone. They’re both powerful, but they’re not the same. One isn’t just a stronger version of the other-it works differently, lasts longer, and can change your experience in ways you might not expect.
How Strong Is Dexamethasone Compared to Prednisone?
Dexamethasone is not just a little stronger-it’s a whole lot stronger. On a milligram-for-milligram basis, dexamethasone is about 9 to 10 times more potent than prednisone. That means if you take 1 mg of dexamethasone, you’re getting roughly the same anti-inflammatory punch as 9-10 mg of prednisone. This isn’t guesswork. Studies using molecular binding tests show dexamethasone sticks to the glucocorticoid receptor more tightly and for longer, turning off inflammation genes more effectively.
That’s why dosing looks so different. A typical prednisone dose might be 20 mg or 40 mg a day. The equivalent dexamethasone dose? Just 2 to 4 mg. For kids with croup, a single 0.6 mg/kg dose of dexamethasone works better than five days of prednisone. In asthma flare-ups, one shot of dexamethasone can replace a full week of pills. It’s not magic-it’s pharmacology.
How Long Do They Last?
Prednisone lasts about 12 to 36 hours in your body. Dexamethasone? 36 to 72 hours. That’s why dexamethasone is called a long-acting steroid, and prednisone is intermediate-acting. This difference changes how you take them.
If you’re being treated for a short-term problem-like a bad allergic reaction, a flare-up of multiple sclerosis, or swelling from a brain tumor-dexamethasone’s long life means fewer doses. One or two pills can do the job. That’s why it became a go-to during the COVID-19 pandemic: hospitalized patients got one daily dose, and it cut death rates by about one-third.
Prednisone, on the other hand, needs to be taken daily, sometimes multiple times a day, especially for chronic conditions like rheumatoid arthritis or lupus. Why? Because its shorter half-life lets doctors fine-tune the dose. If your joint pain flares up, you can bump up the prednisone. If your blood sugar spikes, you can cut back. With dexamethasone, once it’s in your system, it’s there for days. That’s helpful for some things, risky for others.
Side Effects: Are They the Same?
Both drugs can cause the same side effects-weight gain, mood swings, trouble sleeping, high blood sugar, weakened bones, increased infection risk. But because dexamethasone is so much stronger, even small doses can pack a punch.
Here’s where it gets interesting: because you take less dexamethasone, you might actually get fewer side effects overall. For example, a 2017 study in kids with asthma found no real difference in vomiting or nausea between dexamethasone and prednisone. But when you look at long-term patterns, the picture changes.
People on prednisone report more moon face and weight gain. Why? Because they’re taking higher daily doses for longer. One patient might be on 30 mg of prednisone a day for months. That’s a lot of steroid flooding the system. With dexamethasone, you might only take 4 mg a day for a few days. Less total exposure, less fat redistribution.
But dexamethasone wins the insomnia contest. A 2019 study showed 29% of people on dexamethasone had trouble sleeping, compared to 22% on prednisone. Mood swings were also more common-33% vs 26%. That’s likely because dexamethasone stays in your brain longer, affecting neurotransmitters like serotonin and dopamine.
And then there’s blood sugar. Dexamethasone raises glucose levels more sharply. A 2021 meta-analysis found a 18% higher risk of hyperglycemia at equivalent doses. That’s why diabetics need to monitor closely if they’re switched to dexamethasone, even if the dose seems low.
Which One Is Better for Kids?
For children, dexamethasone is often the clear winner. In croup-a condition that causes a barking cough and breathing trouble-dexamethasone cuts hospital readmissions by 24% compared to prednisolone. It’s given as a single swallow or injection. Parents don’t have to fight to get a 5-day course of bitter liquid down their kid’s throat.
Same with asthma. A single dose of dexamethasone works as well as five days of prednisone. Fewer missed school days. Fewer trips to the ER. Fewer bottles to remember. The American Academy of Pediatrics and GINA guidelines both recommend dexamethasone for acute childhood asthma because it’s simpler and just as safe.
What About Chronic Conditions?
If you have lupus, rheumatoid arthritis, or another long-term autoimmune disease, prednisone is still the standard. Why? Control. You need to be able to adjust the dose slowly-lower it when things calm down, raise it when they flare. Dexamethasone’s long half-life makes that hard. If you take it daily for weeks, the drug builds up. You can’t easily dial it back.
Also, long-term steroid use increases osteoporosis risk. The American Geriatrics Society says both drugs are risky for older adults if taken over 7.5 mg prednisone-equivalent daily for more than three months. But because dexamethasone is so potent, even 1.5 mg a day can hit that threshold. That’s why doctors avoid using it for years unless absolutely necessary.
Cost and Accessibility
Prednisone is dirt cheap. A 30-day supply of 20 mg tablets costs around $8.50. Dexamethasone? About $13 for 4 mg tablets. At first glance, prednisone wins. But look closer. You might need only one dexamethasone tablet a day for five days instead of five prednisone tablets a day for five days. That’s 25 pills vs 5. Suddenly, the cost difference shrinks-or even flips.
Plus, fewer pills mean fewer mistakes. Missed doses? Less likely with a single-dose dexamethasone regimen. That’s a hidden benefit, especially for elderly patients or those managing multiple medications.
Real-World Experiences
On Drugs.com, over 1,200 people have reviewed prednisone. More than 40% reported moon face. Almost 60% said they gained weight. For dexamethasone, only 31% saw moon face, and 45% gained weight. But 37% of dexamethasone users said they couldn’t sleep. That’s 8 percentage points higher than prednisone users. Mood swings? 33% vs 26%.
These aren’t just random complaints. They match the science. Dexamethasone’s long action hits the brain harder and longer. Prednisone’s shorter ride gives your body time to reset between doses.
When Do Doctors Choose Which?
It’s not about which is better. It’s about which fits the situation.
- Choose dexamethasone for short-term, high-impact needs: severe asthma attacks, croup, brain swelling, allergic reactions, or as a single dose in the ER. Also preferred for cancer-related pain or nerve compression.
- Choose prednisone for long-term control: rheumatoid arthritis, inflammatory bowel disease, chronic skin conditions. It gives you room to adjust.
Doctors also consider age. For older adults, prednisone is often safer because it’s easier to taper. For kids, dexamethasone is easier to give and just as effective.
What Should You Watch For?
Whether you’re on dexamethasone or prednisone, you need to know the red flags:
- Sudden mood changes, anxiety, or hallucinations
- Unexplained fever, cough, or skin sores (signs of infection)
- Extreme thirst, frequent urination, blurry vision (high blood sugar)
- Severe back or hip pain (possible bone fracture)
- Swelling in ankles or face
Never stop either drug suddenly. Your body gets used to the steroid and stops making its own. Stopping cold can cause adrenal crisis-low blood pressure, vomiting, confusion, even death. Always taper under medical supervision.
Bottom Line
Dexamethasone is the heavyweight: stronger, longer-lasting, perfect for quick, powerful interventions. Prednisone is the workhorse: flexible, familiar, better for long-term management. Neither is ‘better’ overall. The right choice depends on your condition, how long you need treatment, and how your body responds.
If you’re switching from one to the other, ask your doctor: ‘What’s the goal? How long will I be on this? What side effects should I watch for?’ Don’t assume they’re interchangeable. They’re not. And knowing the difference could make your treatment safer, simpler, and more effective.
Dexamethasone wiped out my croup kid’s cough in one dose. No more midnight ER runs. No more bitter liquid battles. I’ll take the insomnia over that any day.
It’s not even close.
As a Canadian nurse who’s administered both in pediatric units, I can say with confidence that dexamethasone’s single-dose efficacy has revolutionized acute asthma management.
Yes, sleep disruption is real-but the reduction in hospitalizations? Worth every restless night.
And for parents? One pill beats five days of coercion any day.
It’s not about preference-it’s about evidence-based simplicity.
Why are we even comparing? Dexamethasone is clearly superior. Prednisone is old-school American laziness. We’re talking about a drug that’s been around since the 50s. Canada’s been using dexamethasone as first-line since 2015. Why are you still clinging to that outdated crap?
It’s not just stronger-it’s smarter. Get with the program.
Excellent breakdown. One point often overlooked: dexamethasone’s longer half-life reduces pill burden, which improves adherence-especially in elderly patients on polypharmacy.
Also, while hyperglycemia risk is higher, the absolute increase is modest in non-diabetics.
The real trade-off isn’t potency-it’s flexibility. Prednisone allows titration; dexamethasone demands precision.
I was on 60mg prednisone for 8 months for my lupus. Moon face? Check. Weight gain? Double check. Sleep? Never happened.
Then my rheum switched me to 4mg dexamethasone for 7 days during a flare. I lost 12 pounds in 10 days. No moon face. No binge eating.
But I didn’t sleep for 72 hours straight. I watched every Netflix show known to man.
It was hell. But worth it. I’d do it again.
Doctors need to tell patients this upfront. Not just ‘side effects.’ Tell us the *real* stuff.
From a pharmacokinetic standpoint, the differential in glucocorticoid receptor affinity (Kd ~0.5nM for dexamethasone vs ~2.5nM for prednisone) underpins the clinical divergence.
Moreover, the hepatic metabolism via CYP3A4 is significantly slower for dexamethasone, resulting in prolonged systemic exposure.
Consequently, the AUC0–∞ is 3–4x higher, explaining the sustained anti-inflammatory effect.
However, the suppression of the HPA axis is more profound and prolonged, necessitating cautious tapering protocols in chronic use.
So you’re telling me I’m supposed to believe that a 4mg pill is somehow safer than 20mg? That’s a joke. Dexamethasone is a chemical monster. It’s not ‘less exposure’-it’s concentrated toxicity.
You think your body doesn’t know the difference? It does. It screams. Insomnia, anxiety, rage-it’s all there.
And don’t get me started on how it wrecks your metabolism. I gained 20lbs in 3 weeks. I’m not ‘just’ diabetic-I’m a walking steroid casualty.
They’re not interchangeable. They’re both monsters. But dexamethasone? It’s the silent killer.
As someone who’s lived with rheumatoid arthritis for 22 years, I’ve tried both.
Prednisone gave me the moon face, the weight, the cravings.
Dexamethasone gave me the sleepless nights, the panic attacks, the heart palpitations.
But here’s the truth: when you’re in pain so deep you can’t hold your coffee cup, you’ll take the devil’s bargain.
Neither is kind. But one is kinder to your daily life.
And that’s the real win.