Prednisone: what it treats, how to take it, side effects
Last updated September 3, 2026.
Prednisone is a corticosteroid that reduces inflammation and changes how the immune system works. It is prescribed for a wide range of conditions, from severe allergic reactions to autoimmune diseases. It is powerful and fast-acting, and it requires careful dosing and a careful exit.
What does it treat?
MedlinePlus lists two big roles. It replaces natural steroids in people whose bodies do not make enough corticosteroids, and in people with normal levels it treats conditions driven by inflammation or an overactive immune system: certain types of arthritis, severe allergic reactions, multiple sclerosis, lupus, and conditions affecting the lungs, skin, eyes, kidneys, blood, thyroid, stomach, and intestines. It is also sometimes used for symptoms of certain cancers.
How do you take it?
Prednisone is usually taken with food, anywhere from one to four times a day or once every other day, on a schedule your doctor sets. The FDA label says the initial adult dose can range from 5 mg to 60 mg per day depending on the disease, and the dose is then adjusted to the lowest amount that controls your symptoms. Swallow delayed-release tablets whole. The single most important rule: do not stop prednisone suddenly. After long-term use the label says it must be withdrawn gradually, because stopping abruptly can leave your body without enough natural steroids - causing extreme tiredness, weakness, upset stomach, weight loss, and salt cravings. Your doctor may also raise the dose temporarily during illness, surgery, or severe stress. If you miss a dose, follow the instructions your doctor gave you ahead of time and never take a double dose.
Side effects to know
- Common: headache, dizziness, trouble sleeping, mood swings, acne, thin or fragile skin, slow healing, increased sweating, heartburn, increased hair growth, changes in where your body stores fat, and irregular periods.
- Serious: vision problems or eye pain; signs of infection like fever, chills, or sore throat (prednisone can hide them); seizures; depression, confusion, or loss of contact with reality; muscle twitching; irregular heartbeat; sudden weight gain; shortness of breath; severe stomach pain or swelling. Call your doctor immediately for any of these.
Who should not take it?
Prednisone needs a careful risk review before starting. Tell your clinician if you have diabetes, high blood pressure, osteoporosis, ulcers, tuberculosis, eye infections, myasthenia gravis, seizures, or heart, liver, kidney, or thyroid disease. Because it weakens immune defenses, avoid people with chickenpox or measles and call your doctor right away if you are exposed. Do not get any vaccines while taking it without your doctor's approval. MedlinePlus flags interactions with St. John's wort, cimetidine, and aspirin. If you are pregnant, planning pregnancy, or breastfeeding, call your doctor. Long-term use raises the risk of osteoporosis and can slow growth in children.
When is it an emergency?
Call 911 for signs of a severe allergic reaction: hives with swelling of the eyes, face, lips, tongue, or throat, or difficulty breathing or swallowing. Get immediate medical care for sudden vision changes, a seizure, severe depression or confusion, or chest pain. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
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Common questions
Why can't I stop taking prednisone suddenly?
After more than a short course, your body slows its own steroid production. MedlinePlus warns that stopping abruptly can cause extreme tiredness, weakness, slowed movements, upset stomach, weight loss, changes in skin color, mouth sores, and salt cravings. The FDA label says prednisone should be withdrawn gradually after long-term therapy, which is why tapers exist.
Does prednisone cause weight gain?
It can, in two ways listed by MedlinePlus. Over time it commonly changes the way fat is spread around the body, and sudden weight gain is on the serious side effect list - if your weight jumps quickly, call your doctor rather than waiting it out, since it can signal fluid retention.
Why does my doctor want me to take prednisone in the morning?
Timing doses to the morning works with your body's natural steroid rhythm. The FDA label explains that a single morning dose causes less suppression of your adrenal system than the same dose spread through the day, which is one reason alternate-day and morning schedules are used.
Can I get vaccinated while taking prednisone?
Not without clearing it first. MedlinePlus is direct: do not have any vaccinations while taking prednisone without talking to your doctor. Prednisone changes how your immune system responds, so your clinician decides which vaccines are safe and when.
Can I drink alcohol while taking prednisone?
Neither the FDA label nor MedlinePlus lists a specific alcohol interaction for prednisone. Because both alcohol and prednisone can irritate the stomach, many clinicians advise limiting or avoiding alcohol during treatment - ask your doctor about your situation.
Are there foods I should eat or avoid on prednisone?
Possibly. MedlinePlus says your doctor may put you on a low-salt, high-potassium, or high-calcium diet, or recommend supplements, because prednisone affects salt and mineral balance. Also ask your doctor about grapefruit and grapefruit juice before having them.
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