Steroid Potency Converter
Dexamethasone vs Prednisone Converter
Convert between dexamethasone and prednisone dosages based on their relative potencies. Dexamethasone is approximately 9-10 times more potent than prednisone.
Enter a dose and select a steroid type to see the conversion.
Dexamethasone is approximately 9-10 times more potent than prednisone on a milligram-for-milligram basis. This means you need much smaller doses of dexamethasone to achieve the same effect as prednisone.
When to use each steroid:
- Dexamethasone: For short-term, powerful treatment (asthma attacks, croup, severe inflammation)
- Prednisone: For longer-term management of chronic conditions (rheumatoid arthritis, lupus)
When doctors prescribe steroids for inflammation or autoimmune conditions, two names come up more than any others: dexamethasone and prednisone. They’re both powerful, but they’re not the same. One is stronger, lasts longer, and can be given in fewer doses. The other is more flexible, easier to adjust, and often used for long-term treatment. Choosing between them isn’t about which is "better"-it’s about which fits your condition, your body, and your life.
How Strong Is Dexamethasone Compared to Prednisone?
Dexamethasone isn’t just a little stronger than prednisone-it’s much stronger. On a milligram-for-milligram basis, dexamethasone is about 9 to 10 times more potent. That means if you need 10 mg of prednisone to control inflammation, you’d only need about 1 mg of dexamethasone to get the same effect. This isn’t guesswork. Studies using advanced techniques like ChIP-seq have shown that the dexamethasone-receptor complex binds to DNA more tightly, turning off inflammatory genes more efficiently.
The numbers back this up. According to the National Adrenal Diseases Foundation’s updated 2023 potency chart, prednisone has a relative potency of 5 (with hydrocortisone as 1), while dexamethasone scores 25 to 50, depending on the effect being measured. That’s why dexamethasone is used in tiny doses: 0.75 mg to 9 mg daily, compared to prednisone’s typical 5 mg to 60 mg range.
Duration Matters: One Dose vs. Five Days
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 a short course-sometimes just one or two pills-and it still works.
For kids with croup or asthma, this matters a lot. A 2006 study found that a single dose of dexamethasone (0.6 mg/kg) reduced hospital revisits by 24% compared to a five-day course of prednisolone. In 2014, a review in Pediatrics confirmed that two doses of dexamethasone worked just as well as five days of prednisone for asthma flare-ups. Parents prefer it. Kids prefer it. And doctors do too-because it’s easier to get compliance when you don’t have to chase a child to take medicine every day.
Side Effects: Is One Safer?
Both drugs cause similar side effects because they work the same way: suppressing your immune system, raising blood sugar, weakening bones, and messing with your mood. But because dexamethasone is so potent and lasts so long, the way these side effects show up can be different.
For example, a 2021 meta-analysis found that at equivalent anti-inflammatory doses, dexamethasone raised blood sugar levels 18% more than prednisone. That’s a big deal for people with diabetes or prediabetes. Insomnia is also more common with dexamethasone-29% of users reported trouble sleeping versus 22% with prednisone. Mood swings? 33% of dexamethasone users said they felt irritable or anxious, compared to 26% on prednisone.
But here’s the twist: because you take less of dexamethasone, some side effects actually show up less. Real-world reviews from 1,247 prednisone users and 783 dexamethasone users showed that prednisone users were more likely to report "moon face," weight gain, and bloating. Why? Probably because they’re taking higher total doses over longer periods. Dexamethasone’s short courses mean less overall exposure, even if each pill is stronger.
When Do Doctors Choose Dexamethasone?
Dexamethasone shines when you need a quick, powerful punch. During the COVID-19 pandemic, the RECOVERY Trial proved it saved lives in hospitalized patients on oxygen. It’s now standard care for severe cases. It’s also the go-to for brain swelling, spinal cord compression, or severe allergic reactions-situations where you need fast, strong suppression of inflammation.
For cancer patients with nerve pain or high pressure in the skull, dexamethasone has been shown to be 35% more effective than prednisone at reducing symptoms, according to a 1995 study cited by the American Academy of Family Physicians. It’s also preferred in some autoimmune conditions like multiple sclerosis flare-ups, where a short, intense burst of steroids can stop damage quickly.
When Is Prednisone the Better Choice?
Prednisone is the workhorse for chronic conditions. If you have rheumatoid arthritis, lupus, or a long-term inflammatory bowel disease, you’re likely to stay on prednisone for months or years. Why? Because its shorter half-life lets doctors fine-tune the dose. Need to cut back slowly? You can drop by 1 mg or 2.5 mg at a time. With dexamethasone, even a 0.5 mg reduction can be too much, too fast.
The American College of Rheumatology’s 2022 guidelines still recommend prednisone as the standard for chronic autoimmune disease management. It’s easier to taper, easier to monitor, and less likely to cause prolonged HPA axis suppression-where your body stops making its own cortisol because it’s been flooded with synthetic steroids for too long.
Cost and Accessibility
On paper, dexamethasone looks more expensive. A 30-tablet pack of 4 mg dexamethasone costs about $12.89 on average, while generic prednisone 20 mg runs $8.47. But here’s the catch: you take far less dexamethasone. A full course of treatment for asthma in a child might cost $2.50 for dexamethasone versus $15 for a five-day prednisone course. In many cases, the total cost ends up being the same-or even lower with dexamethasone.
Both are generic, widely available, and covered by nearly all insurance plans. Neither requires special ordering or prior authorization in most cases.
What About Long-Term Risks?
Any steroid used for more than three months at doses above 7.5 mg prednisone-equivalent daily is flagged by the American Geriatrics Society’s 2022 Beers Criteria as potentially inappropriate for older adults. That’s because long-term use raises the risk of osteoporosis, cataracts, muscle wasting, and infections.
Dexamethasone’s long half-life makes it riskier for chronic use. If you’re on it for more than a few weeks, your body gets used to it harder, and withdrawal becomes more dangerous. Prednisone, with its shorter duration, is easier to wean off gradually. That’s why doctors avoid dexamethasone for long-term maintenance-even if it’s more potent.
Real-World Experience: What Do Patients Say?
Looking at patient reviews on Drugs.com, patterns emerge. Prednisone users report more physical changes: swelling, weight gain, acne, and facial rounding. Dexamethasone users report more mental effects: trouble sleeping, anxiety, mood swings, and vivid dreams.
One 58-year-old woman with rheumatoid arthritis wrote: "Prednisone made me feel like a balloon. I couldn’t fit into my clothes. But I slept fine." Another, a 32-year-old man treated for a severe allergic reaction, said: "Dexamethasone worked in hours. But I didn’t sleep for three nights. I felt like I was on caffeine pills."
Neither is "better"-they just affect people differently.
Bottom Line: Pick Based on Purpose, Not Potency
Use dexamethasone when you need a strong, fast, short-term fix: asthma attacks, croup, brain swelling, cancer-related pain, or acute flare-ups. It’s the sledgehammer.
Use prednisone when you need to manage something long-term: arthritis, lupus, chronic asthma, or autoimmune diseases. It’s the scalpel.
Neither is safe to use without medical supervision. Both can cause serious harm if misused. Always follow your doctor’s dose and schedule. Never stop either suddenly-you could go into adrenal crisis.
If you’re on either drug, get your blood sugar checked regularly. Ask about bone density scans if you’re on it longer than three months. And if you feel unusually anxious, depressed, or can’t sleep-tell your doctor. There might be a better option for you.
Is dexamethasone stronger than prednisone?
Yes, dexamethasone is significantly stronger. On a milligram-for-milligram basis, it’s about 9 to 10 times more potent than prednisone. That means a small dose of dexamethasone can do the same job as a much larger dose of prednisone.
Which steroid has fewer side effects?
It depends. Dexamethasone, because it’s used in lower doses and shorter courses, often causes less weight gain and facial swelling. But it’s more likely to cause insomnia and mood swings due to its long half-life and stronger effect on the brain. Prednisone tends to cause more physical side effects like bloating and moon face because higher total doses are used over longer periods.
Can I switch from prednisone to dexamethasone?
You should never switch on your own. Because dexamethasone is much stronger and lasts longer, switching without medical guidance can lead to overdose or withdrawal. Your doctor can calculate an equivalent dose based on your condition and current dosage, but it must be done carefully.
Why is dexamethasone used in COVID-19?
Dexamethasone was shown in the 2020 RECOVERY Trial to reduce death rates in hospitalized COVID-19 patients who needed oxygen or a ventilator. Its powerful anti-inflammatory effect helps calm the body’s dangerous overreaction to the virus, known as a cytokine storm.
Is dexamethasone better for asthma than prednisone?
For acute asthma attacks, especially in children, dexamethasone is often preferred. A single dose or two-day course works as well as a five-day prednisone course, with better adherence and fewer side effects like vomiting. The Global Initiative for Asthma (GINA) recommends it for this reason.
Can I take dexamethasone or prednisone if I have diabetes?
Both can raise blood sugar, but dexamethasone has been shown to increase it more at equivalent doses. If you have diabetes, your doctor will monitor your glucose closely and may adjust your diabetes meds while you’re on either steroid. Dexamethasone is usually avoided for long-term use in diabetic patients.
How long do side effects last after stopping?
Most side effects fade within days to weeks after stopping, especially if the course was short. But long-term use can lead to lasting issues like bone loss or adrenal suppression. That’s why tapering is critical-your body needs time to restart its own cortisol production. Never stop abruptly.
Which is cheaper: dexamethasone or prednisone?
Prednisone pills are cheaper per tablet, but you take more of them. Dexamethasone costs more per pill, but you take far fewer. For short courses like asthma or croup, dexamethasone often ends up costing less overall. For long-term use, prednisone is usually more economical.
