Dexamethasone is a synthetic glucocorticoid, a man-made version of the body’s stress hormone cortisol. It is one of the most potent corticosteroids in routine use: on the FDA label’s comparison table, 0.75 mg of dexamethasone matches 20 mg of hydrocortisone and 5 mg of prednisone. It is an old, generic, prescription-only drug, labeled for a long list of inflammatory, allergic, autoimmune, blood, cancer and brain-swelling conditions, and in a 20 mg form for multiple myeloma.
Despite the word “steroid,” dexamethasone is not an anabolic steroid. Its labeled effects include protein breakdown, loss of muscle mass and steroid myopathy. It also suppresses the body’s own cortisol production, which is the basis of the dexamethasone suppression test used to diagnose Cushing’s syndrome. In the RECOVERY trial, a low daily dose lowered deaths in patients hospitalized with COVID-19 who needed oxygen or ventilation.
This page summarizes what the FDA labels, randomized trials and the Endocrine Society guideline report. It is for education only and is not medical advice.
| Property | Detail |
|---|---|
| Drug class | Synthetic fluorinated glucocorticoid (corticosteroid); not an anabolic-androgenic steroid |
| Brands / approval | Decadron (Merck, NDA 011664, discontinued); Hemady 20 mg tablets (NDA 211379, approved 2019); many generics |
| Routes | Oral tablets, elixir and solution; IV/IM injection (dexamethasone sodium phosphate); intra-articular, soft-tissue and intralesional injection; eye and ear products |
| Tablet strengths | 0.5, 0.75, 1, 1.5, 2, 4 and 6 mg (generic); 20 mg (Hemady) |
| Labeled oral dose | 0.75–9 mg/day initially, individualized; 20 or 40 mg on set days in myeloma regimens |
| Potency (label) | 0.75 mg ≈ 5 mg prednisone ≈ 20 mg hydrocortisone; almost no salt-retaining effect |
| Half-life (label) | Plasma ≈ 4 h, but a single dose keeps cortisol suppressed for about 3 days |
| US status | Prescription only; not a controlled substance |
| WADA status | S9 glucocorticoid: prohibited in-competition by injectable, oral (including oromucosal) and rectal routes |
What it is
Dexamethasone’s chemical name is (11β,16α)-9-fluoro-11,17,21-trihydroxy-16-methylpregna-1,4-diene-3,20-dione: formula C₂₂H₂₉FO₅, molecular weight 392.47 g/mol (generic tablet label). The label describes it as a 9-fluoro glucocorticoid with anti-inflammatory effects and low mineralocorticoid activity (Hemady label). The original brand, Merck’s Decadron tablets (NDA 011664), is discontinued in the US (Drugs@FDA), and generics are now the main source.
Like cortisol, it has what the label calls “varied metabolic effects” and modifies the immune response to many triggers. Natural glucocorticoids (hydrocortisone, cortisone) also make the kidneys hold on to sodium. At equipotent anti-inflammatory doses, dexamethasone “almost completely lacks” that sodium-retaining effect (generic tablet label). This is why it is chosen when strong anti-inflammatory action without fluid load is wanted, as in brain swelling, and why it is not the drug of choice for replacing missing adrenal hormones.
Potency compared with other glucocorticoids
The tablet label lists the following oral or IV doses as roughly equivalent (generic tablet label):
| Corticosteroid | Equivalent dose |
|---|---|
| Cortisone | 25 mg |
| Hydrocortisone | 20 mg |
| Prednisone | 5 mg |
| Prednisolone | 5 mg |
| Methylprednisolone | 4 mg |
| Triamcinolone | 4 mg |
| Paramethasone | 2 mg |
| Betamethasone | 0.75 mg |
| Dexamethasone | 0.75 mg |
The label adds that these relationships apply only to oral or intravenous use. When the drugs are injected into muscle or joints, their relative properties “may be greatly altered.” For a broader introduction to how glucocorticoids differ from anabolic steroids, see the prednisone page.
Pharmacokinetics
Most modern pharmacokinetic data come from the Hemady label (Hemady label):
| Parameter | Value |
|---|---|
| Dose proportionality | Linear across single oral doses of 0.5–40 mg |
| Time to peak (20 mg) | Median 1 h (range 0.5–4 h) |
| Peak level (20 mg) | 247 ng/mL (geometric mean) |
| Effect of a high-fat meal | No change in total exposure; peak 23% lower |
| Plasma protein binding | About 77% |
| Terminal half-life | About 4 h |
| Metabolism | CYP3A4 (liver) |
| Urinary excretion | Under 10% of the dose |
The short plasma half-life understates how long the drug acts. After a single oral dose in healthy people, the fall in blood cortisol was greatest at about 12 hours, and cortisol returned to near baseline only about 3 days later (Hemady label). This prolonged hormonal effect, rather than the plasma half-life, is what “long-acting” refers to for dexamethasone.
Because CYP3A4 clears it, other drugs can change its levels a lot. Itraconazole (a strong CYP3A4 inhibitor) raised dexamethasone exposure 3.7-fold, and aprepitant (a moderate inhibitor) raised it 2.2-fold. Strong inducers such as rifampin, phenytoin and carbamazepine lower it (Hemady label; generic tablet label). Dexamethasone is itself a moderate CYP3A4 inducer, so it can lower levels of other drugs cleared by that enzyme.
Approved medical use
Tablets and injection
The generic tablet label lists indications across almost every organ system (generic tablet label), including:
- Allergic states: severe asthma, atopic and contact dermatitis, drug reactions, allergic rhinitis and serum sickness not controlled by conventional treatment.
- Rheumatic and autoimmune disease: short-term add-on for flares of rheumatoid, psoriatic and gouty arthritis and ankylosing spondylitis; treatment of lupus, dermatomyositis and polymyositis.
- Skin, eye, gut, kidney and lung disease: for example pemphigus, uveitis, flares of ulcerative colitis and Crohn’s disease, nephrotic syndrome and symptomatic sarcoidosis.
- Blood and cancer: autoimmune hemolytic anemia, immune thrombocytopenia in adults, and palliative management of leukemias and lymphomas.
- Nervous system: acute flares of multiple sclerosis and cerebral edema from brain tumors, craniotomy or head injury.
- Endocrine: adrenal insufficiency (where the label notes hydrocortisone or cortisone is the drug of choice), congenital adrenal hyperplasia and cancer-related hypercalcemia.
- Diagnostic testing of adrenal overactivity (the suppression test below).
Dexamethasone is also marketed as oral elixirs and solutions, eye and ear drops (often combined with antibiotics), and eye implants and inserts (DailyMed product listing). The injectable form, dexamethasone sodium phosphate, is labeled for IV or IM use when oral therapy is not feasible, and some products also for joint, soft-tissue and lesion injection (Fresenius Kabi injection label). The label notes that the phosphate ester is water-soluble and “produces a rapid response even when injected intramuscularly.”
Labeled dosing examples
| Situation | Labeled regimen | Source |
|---|---|---|
| General oral starting dose | 0.75–9 mg/day, then reduce stepwise to the lowest effective dose | Tablet label |
| Acute multiple sclerosis flare | 30 mg/day for 1 week, then 4–12 mg every other day for 1 month | Tablet label |
| Cerebral edema (adults) | 10 mg IV, then 4 mg IM every 6 h; taper over 5–7 days | Injection label |
| Children (oral) | 0.02–0.3 mg/kg/day in 3–4 divided doses | Tablet label |
| Multiple myeloma (Hemady) | 20 or 40 mg once daily on specific days of the combination regimen | Hemady label |
The labels stress that dosing “must be individualized” to the disease and the response, and that after long-term use the drug should be withdrawn gradually.
Hemady for multiple myeloma
Hemady is a 20 mg dexamethasone tablet approved by the FDA in October 2019 (Drugs@FDA, NDA 211379). It is indicated in combination with other anti-myeloma drugs for adults with multiple myeloma. The label states that dexamethasone induces programmed death (apoptosis) of myeloma cells, though the exact mechanism in myeloma is unknown (Hemady label).
The dexamethasone suppression test
Because dexamethasone suppresses the HPA axis (the hormone chain that controls cortisol), a healthy person’s own cortisol falls after a small dose. In Cushing’s syndrome (long-term cortisol excess), cortisol stays high. The tablet label describes these protocols (generic tablet label):
| Test | Protocol on the label | Purpose |
|---|---|---|
| Overnight 1 mg test | 1 mg orally at 11 p.m.; plasma cortisol drawn at 8 a.m. | Screening for Cushing’s syndrome |
| Low-dose 48 h test | 0.5 mg every 6 h for 48 h with 24 h urine collections | More accurate screening |
| High-dose 48 h test | 2 mg every 6 h for 48 h with 24 h urine collections | Separating pituitary ACTH excess (Cushing’s disease) from other causes |
The Endocrine Society guideline lists the 1 mg overnight test or the 2 mg/day 48 h test as acceptable first-line tests (Nieman et al., JCEM 2008). It recommends a morning serum cortisol cutoff of 1.8 µg/dL (50 nmol/L): above that, suppression is considered abnormal. At this cutoff sensitivity is over 95%, at the cost of a specificity of about 80%. Raising the cutoff to 5 µg/dL pushes specificity above 95% but misses more cases.
Several things can distort the result, according to the guideline and the label:
- Oral estrogens. They raise cortisol-binding globulin, so total cortisol reads high. False-positive results occurred in 50% of women taking the oral contraceptive pill; the guideline advises stopping estrogen-containing drugs 6 weeks before testing where possible.
- CYP3A4 inducers (phenobarbital, phenytoin, carbamazepine, rifampin and others) speed dexamethasone clearance and can cause false positives. CYP3A4 inhibitors (itraconazole, ritonavir, aprepitant and others) can do the reverse.
- Indomethacin. The tablet label notes reports of false-negative results.
What the research shows
COVID-19: the RECOVERY trial
RECOVERY was a large, open-label randomized platform trial. It assigned 2,104 patients hospitalized with COVID-19 to dexamethasone 6 mg once daily (oral or IV) for up to 10 days and 4,321 to usual care (RECOVERY Collaborative Group, NEJM 2021). The primary outcome was death within 28 days.
| Respiratory support at randomization | Dexamethasone deaths | Usual care deaths | Rate ratio (95% CI) |
|---|---|---|---|
| All patients | 22.9% | 25.7% | 0.83 (0.75–0.93) |
| Invasive mechanical ventilation | 29.3% | 41.4% | 0.64 (0.51–0.81) |
| Oxygen without ventilation | 23.3% | 26.2% | 0.82 (0.72–0.94) |
| No respiratory support | 17.8% | 14.0% | 1.19 (0.92–1.55) |
The benefit was largest in the sickest patients. In those who did not need oxygen, there was no benefit, and the point estimate leaned toward harm.
A higher dose did not clearly add more. COVID STEROID 2 randomized 1,000 adults with severe hypoxemia (low blood oxygen) to 12 mg or 6 mg IV dexamethasone daily for up to 10 days (COVID STEROID 2 Trial Group, JAMA 2021). Median days alive without life support at 28 days were 22.0 vs 20.5 (adjusted difference 1.3 days, 95% CI 0–2.6; p = 0.07). 28-day mortality was 27.1% vs 32.3%, not a statistically significant difference, and the authors noted the trial may have been underpowered.
Bacterial meningitis
In a double-blind European trial, 301 adults with acute bacterial meningitis received dexamethasone 10 mg or placebo every 6 hours for 4 days, starting with or just before the first antibiotic dose (de Gans and van de Beek, NEJM 2002).
| Outcome at 8 weeks | Relative risk (95% CI) |
|---|---|
| Unfavorable outcome, all patients | 0.59 (0.37–0.94) |
| Death, all patients | 0.48 (0.24–0.96) |
| Unfavorable outcome, pneumococcal meningitis (26% vs 52%) | 0.50 (0.30–0.83) |
Gastrointestinal bleeding was not increased (2 patients on dexamethasone vs 5 on placebo).
Multiple myeloma: high vs low dose
High-dose dexamethasone has long been a backbone of myeloma treatment, but more is not always better. In the ECOG E4A03 trial, 445 people with newly diagnosed myeloma received lenalidomide plus either high-dose dexamethasone (40 mg on days 1–4, 9–12 and 17–20 of each 28-day cycle) or low-dose dexamethasone (40 mg once weekly) (Rajkumar et al., Lancet Oncol 2010).
| Outcome | High dose | Low dose |
|---|---|---|
| Response within 4 cycles | 79% | 68% |
| 1-year overall survival | 87% | 96% (p = 0.0002) |
| Grade 3 or worse toxicity, first 4 months | 52% | 35% |
| Deep-vein thrombosis | 26% | 12% |
| Infections including pneumonia | 16% | 9% |
| Deaths in first 4 months | 12 of 222 | 1 of 220 |
The higher dose produced more responses but more toxicity and worse early survival, and the trial was stopped early.
Preterm birth in low-resource countries
The WHO ACTION-I trial randomized 2,852 pregnant women between 26 weeks 0 days and 33 weeks 6 days of gestation who were at risk of early preterm birth, in Bangladesh, India, Kenya, Nigeria and Pakistan, to intramuscular dexamethasone or placebo (WHO ACTION Trials Collaborators, NEJM 2020). It was stopped early for benefit:
- Neonatal death: 19.6% vs 23.5% (RR 0.84, 95% CI 0.72–0.97).
- Stillbirth or neonatal death: 25.7% vs 29.2% (RR 0.88, 95% CI 0.78–0.99).
- Possible maternal bacterial infection: 4.8% vs 6.3% (RR 0.76, 95% CI 0.56–1.03), so not increased by dexamethasone.
A single dose during surgery
Dexamethasone is widely given during anesthesia to prevent nausea and vomiting, a use outside the US label. The PADDI trial tested whether this raises wound infection risk. 8,880 adults having non-urgent, non-cardiac surgery of at least 2 hours received 8 mg IV dexamethasone or placebo (Corcoran et al., NEJM 2021):
| Outcome | Dexamethasone | Placebo |
|---|---|---|
| Surgical-site infection within 30 days | 8.1% | 9.1% |
| Nausea or vomiting in first 24 h | 42.2% | 53.9% |
| Hyperglycemic events (no diabetes) | 0.6% | 0.2% |
Dexamethasone met the trial’s non-inferiority margin for infection and reduced nausea and vomiting (RR 0.78, 95% CI 0.75–0.82). Even one dose raised blood sugar events slightly in people without diabetes.
Side effects and risks
The tablet label carries no boxed warning, but its warnings cover most organ systems. The risk of complications depends on “the size of the dose and the duration of treatment” (generic tablet label).
HPA axis suppression and withdrawal
Dexamethasone suppresses the hypothalamic-pituitary-adrenal (HPA) axis, the hormone chain that controls the body’s own cortisol. After withdrawal this can leave the adrenal glands unable to respond to stress (secondary adrenal insufficiency). The Hemady label warns that acute adrenal insufficiency after abrupt withdrawal “can be fatal,” that its severity depends on dose, frequency and duration, and that it may persist for months after treatment ends (Hemady label). Gradual tapering reduces the risk.
The label also describes a separate steroid “withdrawal syndrome” after abrupt stopping, with symptoms such as loss of appetite, nausea, lethargy, headache, fever, joint and muscle pain and weight loss. Prolonged use can cause Cushing’s syndrome: a round face, central fat gain with thin limbs, purple stretch marks, easy bruising, muscle weakness and bone loss.
Infection
Corticosteroids, including dexamethasone, increase the risk of infection with any type of pathogen, can reactivate latent infections and can mask the signs of infection. The rate of infections rises with dose. The labels specifically warn about tuberculosis reactivation, severe chickenpox and measles in non-immune people, hepatitis B reactivation, fungal infections and Strongyloides (threadworm) hyperinfection. Live vaccines are contraindicated at immunosuppressive doses (generic tablet label).
Muscle, bone and metabolism
Despite the name, glucocorticoids are catabolic for muscle. The label lists negative nitrogen balance from protein breakdown, loss of muscle mass, muscle weakness and steroid myopathy. High doses can cause an acute myopathy, mostly in people with myasthenia gravis or on neuromuscular-blocking drugs, that may involve breathing muscles; recovery can take “weeks to years” (Hemady label). Research, largely in animals and cell culture, links this to more protein breakdown through the ubiquitin-proteasome system and less protein synthesis through inhibition of the mTOR pathway, with fast-twitch fibers most affected (Schakman et al., Int J Biochem Cell Biol 2013).
Other labeled effects:
- Bone: less bone formation and more bone resorption, leading to osteoporosis, vertebral fractures and aseptic necrosis (bone death) of the hip and shoulder; slowed growth in children.
- Blood sugar: higher glucose, worsening of diabetes and new diabetes on long-term use.
- Fluid and electrolytes: raised blood pressure, sodium retention and potassium loss, mostly at large doses for the synthetic steroids.
- Mood: euphoria, insomnia, mood swings, severe depression and psychosis, usually within days to weeks of starting; depressive episodes may follow stopping.
- Eyes: cataracts and glaucoma; the label advises eye-pressure monitoring beyond 6 weeks of use.
- Gut: peptic ulcer and perforation, with signs that may be masked.
Blood clots
The Hemady label lists venous and arterial thromboembolism as a known adverse reaction of dexamethasone. The risk rises significantly when it is combined with myeloma drugs such as thalidomide, lenalidomide, pomalidomide and carfilzomib, and may also rise with erythropoietin-stimulating agents or estrogen-containing therapies (Hemady label).
Injection-specific risks
The injection label warns that serious neurologic events, some fatal, including spinal cord infarction, paralysis, blindness and stroke, have been reported with epidural corticosteroid injection. Epidural use is not approved. Frequent joint injections may damage joint tissue (Fresenius Kabi injection label).
Key interactions
From the labels:
- Strong CYP3A4 inhibitors (itraconazole, ketoconazole, clarithromycin, ritonavir, cobicistat): higher dexamethasone levels and more side effects. See ketoconazole, which also blocks adrenal steroid production on its own.
- CYP3A4 inducers (rifampin, phenytoin, carbamazepine, barbiturates): lower dexamethasone levels and possible loss of effect. Phenytoin levels may also go up or down.
- NSAIDs and aspirin: more gastrointestinal side effects.
- Warfarin: response is usually reduced, so clotting tests need closer monitoring.
- Diuretics, amphotericin B and digoxin: risk of low potassium, and arrhythmias with digoxin.
- Diabetes medicines: doses may need adjusting because glucose rises.
- Thalidomide: toxic epidermal necrolysis has been reported with the combination.
Who should not use it
The labels contraindicate dexamethasone in systemic fungal infections and in people hypersensitive to the product (generic tablet label). Corticosteroids should be avoided in cerebral malaria and active ocular herpes simplex. The Hemady label warns it can cause fetal harm, and corticosteroids pass into breast milk.
Anti-doping and legal status
All glucocorticoids, dexamethasone among them, are in class S9 of the WADA 2026 Prohibited List. The key rules are:
| Rule | 2026 list |
|---|---|
| When prohibited | In-competition only (in principle from 11:59 p.m. the day before a competition to the end of it and sample collection) |
| Prohibited routes | Any injectable, oral (including oromucosal: buccal, gingival, sublingual) or rectal route |
| Not prohibited | Inhaled and topical routes (dental-intracanal, dermal, intranasal, ophthalmological, otic and perianal) within licensed doses and indications |
| Category | Specified Substance |
In practice, dexamethasone tablets, IV or IM injections and joint or soft-tissue injections fall under the ban when used in-competition, while eye and ear drops used within their licensed doses and indications do not.
In the US, dexamethasone is a prescription-only drug (“Rx only” on the labels). It is not an anabolic steroid and is not listed among the Schedule III anabolic steroids (21 CFR 1308.13).
Key takeaways
- A potent, long-acting glucocorticoid. 0.75 mg equals about 5 mg prednisone or 20 mg hydrocortisone, with almost no salt-retaining effect. The plasma half-life is about 4 hours, but one dose suppresses cortisol for about 3 days.
- Broadly approved. Labeled for allergic, rheumatic, skin, blood, cancer, kidney and neurologic conditions, cerebral edema, multiple myeloma (Hemady) and adrenal testing.
- Lifesaving in the right patients. In RECOVERY, 6 mg/day cut 28-day deaths in COVID-19 patients on oxygen or ventilation, but not in those who needed no oxygen. It also improved outcomes in adult bacterial meningitis and in early preterm birth in low-resource countries.
- More is not always better. In myeloma, high-dose dexamethasone caused more clots, infections and early deaths than a weekly dose.
- Catabolic, not anabolic. Labeled risks include muscle loss, myopathy, bone loss, high blood sugar, infection, mood changes and adrenal suppression that can last months after stopping.
- Banned in-competition by most routes. WADA S9 prohibits oral, injectable and rectal use in-competition; licensed eye, ear, skin and inhaled use is allowed.
Sources
- Advagen Pharma / CorePharma. Dexamethasone tablets, USP, prescribing information. Rev. 07/2025. DailyMed.
- Dexcel Pharma / Edenbridge Pharmaceuticals. Hemady (dexamethasone tablets) 20 mg prescribing information. DailyMed.
- Fresenius Kabi USA. Dexamethasone sodium phosphate injection, USP, prescribing information. Revised March 2026. DailyMed.
- Food and Drug Administration. Drugs@FDA: Hemady, NDA 211379 (original approval October 3, 2019). FDA.
- Food and Drug Administration. Drugs@FDA: Decadron tablets (Merck), NDA 011664, discontinued. FDA.
- Nieman LK, Biller BM, Findling JW, et al. The diagnosis of Cushing’s syndrome: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2008;93(5):1526–1540. PubMed; PMC.
- RECOVERY Collaborative Group, Horby P, Lim WS, Emberson JR, et al. Dexamethasone in hospitalized patients with Covid-19. N Engl J Med. 2021;384(8):693–704. PubMed.
- COVID STEROID 2 Trial Group, Munch MW, Myatra SN, Vijayaraghavan BKT, et al. Effect of 12 mg vs 6 mg of dexamethasone on the number of days alive without life support in adults with COVID-19 and severe hypoxemia: the COVID STEROID 2 randomized trial. JAMA. 2021;326(18):1807–1817. PubMed.
- de Gans J, van de Beek D; European Dexamethasone in Adulthood Bacterial Meningitis Study Investigators. Dexamethasone in adults with bacterial meningitis. N Engl J Med. 2002;347(20):1549–1556. PubMed.
- Rajkumar SV, Jacobus S, Callander NS, et al. Lenalidomide plus high-dose dexamethasone versus lenalidomide plus low-dose dexamethasone as initial therapy for newly diagnosed multiple myeloma: an open-label randomised controlled trial. Lancet Oncol. 2010;11(1):29–37. PubMed.
- WHO ACTION Trials Collaborators, Oladapo OT, Vogel JP, Piaggio G, et al. Antenatal dexamethasone for early preterm birth in low-resource countries. N Engl J Med. 2020;383(26):2514–2525. PubMed.
- Corcoran TB, Myles PS, Forbes AB, et al. Dexamethasone and surgical-site infection. N Engl J Med. 2021;384(18):1731–1741. PubMed.
- Schakman O, Kalista S, Barbé C, et al. Glucocorticoid-induced skeletal muscle atrophy. Int J Biochem Cell Biol. 2013;45(10):2163–2172. PubMed.
- World Anti-Doping Agency. World Anti-Doping Code International Standard: Prohibited List 2026 (S9 Glucocorticoids). In effect January 1, 2026. WADA 2026 Prohibited List.
- US Code of Federal Regulations. 21 CFR 1308.13, Schedule III. 21 CFR 1308.13.
- National Library of Medicine. DailyMed: product labels containing dexamethasone. DailyMed.