Does a Cortisone Shot Cause Weight Gain?

A single cortisone shot is unlikely to add noticeable pounds to the scale. The evidence consistently shows that one or even a short series of local injections does not produce the kind of weight gain people associate with steroid use. But the story has layers: the drug does enter your bloodstream, it does temporarily shift your metabolism, and over time, repeated injections may nudge weight upward in certain people. The gap between a single shot and long-term use matters enormously, and so do individual factors like sex and body composition.

A Local Injection Is Not Purely Local

When a doctor injects a corticosteroid into your knee, shoulder, or spine, the medication does not stay neatly inside that joint. Studies measuring blood cortisol levels after a single intra-articular injection find that the body’s own cortisol production drops within 24 hours, evidence that the synthetic steroid has reached the bloodstream and signaled the adrenal glands to stand down. In one study, cortisol levels fell by an average of about 22% within a day of a joint injection, and some patients’ levels dropped below the normal range for up to 72 hours. Intramuscular injections suppressed cortisol even more, with levels falling by roughly 31% at the 72-hour mark.

This systemic leakage varies widely from person to person. A review of the available research concluded that both intra-articular and epidural injections can produce measurable systemic effects lasting weeks, not just days. In rare cases, repeated local injections have even triggered Cushing syndrome, a condition normally associated with prolonged oral steroid use, along with elevated blood sugar and reduced bone density.

So the notion that a cortisone shot stays in the joint and has zero body-wide effects is wrong. The real question is whether the amount of drug that leaks into the bloodstream is enough to cause something as complex as weight gain.

What the Largest Studies Actually Show

The most informative data on this question comes from a Dutch population study that tracked over 100,000 participants over several years, comparing weight changes in people who started using corticosteroids against those who did not. People who began any form of corticosteroid, including local injections, gained slightly more weight per year than nonusers. Those who started local corticosteroid use specifically gained about 0.037 kilograms more per year than the comparison group. For context, that is roughly an extra ounce and a half annually, an amount you would never notice on a bathroom scale.

The story was different for systemic corticosteroids, the oral and intravenous forms. People starting those experienced a more meaningful increase in waist circumference, gaining about an extra 0.2 centimeters per year around the middle compared to nonusers. That distinction matters: it suggests that the route of delivery, and therefore the total steroid exposure, drives the metabolic consequences. A cortisone shot is simply delivering far less drug systemically than a daily prednisone pill.

Epidural steroid injections, which are among the most common types of cortisone shots for back pain, have been studied separately. One investigation looking specifically at patients who received a series of three epidural injections found no significant change in weight afterward.

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Taken together, the picture is fairly reassuring for someone getting an occasional cortisone shot. The weight effect of local injections, when it appears at all in large studies, is tiny. The clinically significant weight gain people worry about is driven by oral or systemic steroid use, not a knee injection.

Some People Are More Susceptible Than Others

The Lifelines cohort study did not find a uniform effect across all participants. The small weight and waist-circumference changes associated with local corticosteroid use showed up primarily in women and in people who already had a BMI of 25 or higher at the start of the study. Men and those with a BMI below 25 did not show a statistically significant effect.

This pattern makes biological sense. Fat tissue is not passive; it actively responds to hormonal signals, and corticosteroids promote fat storage, particularly around the abdomen. People who already carry more fat tissue may be more responsive to even small systemic doses of steroid. The sex difference could reflect hormonal interactions, differences in body composition, or both, though the study did not pin down a specific mechanism.

One encouraging finding from the same study: people who stopped using corticosteroids saw their waist circumference decrease compared to those who continued. That suggests whatever metabolic shift occurs is at least partially reversible once the steroid exposure ends.

Blood Sugar Disruption Is the More Immediate Concern

While weight gain from a single cortisone shot is negligible for most people, the metabolic disruption is real in a different way: blood sugar spikes. Corticosteroids counteract insulin, temporarily making cells less responsive to it. For someone without diabetes, this blip resolves on its own. For someone with diabetes, it can be a genuine problem.

A study of diabetic patients receiving corticosteroid injections into the hand or wrist found that fasting blood glucose jumped significantly on the first day after the injection, rising by an average of about 43 mg/dL. The spike was still present but smaller on day two, and by day four, blood sugar levels had returned to baseline.

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A separate study looking at musculoskeletal steroid injections in diabetic patients confirmed that pattern. Blood glucose was significantly elevated one day after the injection but not by day two. Patients with poorly controlled diabetes, specifically those with an HbA1c above 7%, and those on insulin therapy experienced larger spikes.

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This blood sugar effect does not directly translate to weight gain from a single injection. But it matters for two reasons. First, if you have diabetes and are getting cortisone shots, you should monitor your blood sugar closely for a couple of days afterward and possibly adjust your medication with your doctor’s guidance. Second, the glucose and insulin disruption is the very mechanism by which chronic steroid exposure eventually leads to fat accumulation. A single brief spike will not do it, but the mechanism is the same one that causes problems with long-term use.

Why Reducing Pain Does Not Automatically Increase Activity

One argument you sometimes hear is that cortisone shots should help with weight management because they relieve pain, which should let you move more and burn more calories. The logic sounds airtight, but the data do not back it up nearly as cleanly as you might expect.

Researchers studying chronic low-back-pain patients who received paravertebral nerve blocks found that while pain dropped by about 55% and in-clinic walking tests improved significantly, the patients’ actual daily physical activity at home did not change. They were not taking more steps. They were not spending more time walking or standing. The study’s authors suggested that fear-avoidance behavior, a conditioned psychological pattern of limiting movement to prevent pain, continued to suppress activity even after the pain itself improved.

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This finding is a useful reality check. If you have been relatively inactive due to pain and you receive a cortisone shot, the pain relief alone may not be enough to shift your activity levels. Chronic pain rewires habits and movement patterns, and undoing that rewiring usually requires deliberate effort, like physical therapy or a structured exercise plan, rather than just the absence of pain. In terms of the weight question, counting on a cortisone shot to boost your calorie burn through increased mobility is optimistic unless you pair it with an active effort to move more.

Local Tissue Changes Near the Injection Site

There is one cosmetic concern worth knowing about that sometimes gets confused with weight gain: subcutaneous atrophy. When corticosteroid is injected close to the surface of the skin, or when some of the drug migrates along tissue planes, it can break down fat and collagen in the immediate area. The result is a visible dent or depression in the skin at the injection site. A case report described this happening in a patient who received a triamcinolone injection for shoulder bursitis, and the authors noted that the complication is relatively common but often unrecognized.

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This is essentially the opposite of weight gain at the local level. The steroid is potent enough to dissolve fat tissue nearby, which is why experienced clinicians inject deeply into the joint or muscle rather than into the soft tissue just below the skin. Skin lightening (depigmentation) around the injection site can also occur for the same reason. Both effects tend to improve over months, though they do not always fully resolve.

If you notice a dimple or sunken area near where you received a cortisone shot, that is atrophy, not fat redistribution. It is a localized cosmetic issue rather than a sign that the steroid is affecting your body composition broadly.

Why the Fear of Weight Gain Is So Persistent

The concern about cortisone shots and weight gain does not come from nowhere. Oral corticosteroids like prednisone genuinely do cause weight gain, often substantial, when taken for weeks or months. The two most commonly discussed side effects in an analysis of nearly 100,000 social media posts mentioning prednisone or prednisolone were insomnia and weight gain. Those posts mentioned weight gain far more frequently than formal adverse-event reporting systems did, suggesting that the experience of steroid-related weight gain looms large in patients’ minds.

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The problem is that people mentally lump all corticosteroids together. A cortisone shot into a knee and a six-week course of oral prednisone involve the same class of drug, but the total systemic exposure is dramatically different. Oral steroids bathe every cell in the body in glucocorticoid for as long as you take them. A local injection delivers a depot of drug that leaks slowly and in much smaller quantities into the bloodstream. The fear people carry about cortisone shots is often transplanted from their experience with oral steroids, or from hearing about someone else’s experience on prednisone, and that fear is not proportional to the actual risk from an injection.

That said, the fear is not completely irrational either. As the systemic absorption research shows, cortisone shots do affect the body beyond the joint. It is just that the magnitude of the effect is far smaller than what happens with oral steroids, and the evidence for clinically meaningful weight gain from occasional injections is weak.

Metabolic Effects in Animals Point to the Same Pattern

Veterinary research provides a useful window into the biology, because it removes the psychological and behavioral confounders that make human studies messy. A study in horses examined the metabolic fallout from a single intra-articular injection of triamcinolone, one of the most commonly used corticosteroids in both equine and human medicine. Within hours, the horses’ cortisol levels dropped significantly, their resting blood glucose rose, and insulin levels climbed. These effects lasted roughly two to five days before normalizing.

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The horses did not gain weight from a single injection. But the metabolic signature, suppressed cortisol, elevated glucose, rising insulin, is exactly the biochemical profile that, if sustained over weeks or months with repeated dosing, leads to fat accumulation. In horses, this is a well-recognized risk with chronic steroid use, and it mirrors what happens in humans on long-term oral steroids. The animal data reinforce the same conclusion as the human studies: a single injection produces a transient metabolic disturbance that resolves, while sustained exposure is what drives lasting body-composition changes.

Repeated Injections and Cumulative Risk

Most orthopedic guidelines recommend limiting cortisone injections to a given joint to three or four per year, partly to protect cartilage and partly because the systemic effects accumulate. The question is whether someone who gets, say, two or three injections per year in different joints over several years is meaningfully different from someone who gets a single shot once.

The Lifelines cohort study suggests the answer is yes, at least slightly. The weight difference it detected, small as it was, appeared in people who were ongoing or new users of local corticosteroids over the follow-up period, not in people who got a single injection and stopped. And the finding that stopping corticosteroid use was associated with a decrease in waist circumference implies that the effect is dose-dependent and reversible.

If you are someone who receives cortisone injections regularly for chronic conditions like osteoarthritis in multiple joints, the cumulative systemic exposure edges closer to what you would get from intermittent oral steroid use. That does not mean you should refuse injections, as the pain relief and functional benefits often outweigh a tiny weight effect. But it is worth having an honest conversation with your doctor about total steroid exposure if you are receiving injections frequently across multiple sites.

Appetite Changes and Fluid Retention

Even when a cortisone shot does not cause true fat gain, some people notice that they feel hungrier or slightly bloated for a few days afterward. Corticosteroids stimulate appetite through effects on the hypothalamus, and they promote sodium and water retention, both of which can cause a transient bump on the scale. A pound or two of water weight in the days following an injection is plausible and should not be confused with fat gain. It typically resolves within a week.

The appetite effect is more concerning with oral steroids because the drug level stays elevated around the clock. With a local injection, the systemic drug level peaks quickly and then tapers, so any appetite increase tends to be mild and short-lived. But if you notice increased hunger after a shot, that is the steroid talking, and being aware of it can help you avoid overeating during the window when the drug is circulating most actively.

What to Watch for If You Are Getting Cortisone Shots

The practical advice is straightforward. If you are getting a single cortisone injection or an occasional shot once or twice a year, weight gain is not something you need to worry about. The systemic dose is too small and too brief. If you have diabetes, watch your blood sugar carefully for the first two days after the injection and talk to your doctor about adjusting your insulin or medication in advance. If you notice a dimple or skin change near the injection site, that is a local tissue effect, not a sign of systemic problems.

If you are receiving multiple injections across different joints over the course of a year, or getting repeat injections every few months in the same joint, pay attention to whether your weight or waist measurement is creeping up over time. The effect, if it occurs, is most likely to show up in women and in people who already carry extra weight. And if your steroid use eventually stops, the available evidence suggests the modest metabolic shift will reverse.