Steroid injections are frequently used medical tools for reducing inflammation and managing pain across various conditions, such as joint pain or severe allergic reactions. The compounds used are synthetic versions of cortisol, known as corticosteroids, not the anabolic steroids associated with muscle building. A common concern is the possibility of weight gain, an effect often observed in patients undergoing long-term steroid therapy. Understanding how the medication is administered helps determine the likelihood of this side effect.
Injection Type Dictates Weight Impact
The risk of gaining weight depends heavily on the amount of medication that reaches the entire body, determined by the route of administration and duration of use. When corticosteroids are delivered through localized injections, such as joint or epidural injections, the risk of systemic side effects is low. These injections target a specific area to reduce inflammation, meaning only a minimal amount of the drug is absorbed into the bloodstream. A single, low-dose injection (often 10 to 40 milligrams) rarely causes noticeable weight fluctuation because the medication is quickly eliminated within a few weeks.
The situation changes when the steroid is administered systemically, which includes high-dose intramuscular injections or long-term oral tablets. Systemic administration means the medication circulates throughout the entire body and affects multiple physiological processes, increasing the potential for side effects. Patients on systemic corticosteroid therapy, such as taking more than 7.5 milligrams of prednisone daily for over 60 days, are at a much greater risk of experiencing weight gain. In these cases, the dose and the duration of exposure are the primary factors influencing the likelihood and severity of the weight change.
How Corticosteroids Affect Metabolism
Corticosteroids influence body weight by mimicking the actions of the natural stress hormone cortisol, altering several metabolic pathways. One immediate effect is an increase in appetite, which can lead to higher caloric intake and subsequent weight gain. The medication also impacts electrolyte balance, causing the body to retain sodium and water. This process results in fluid retention and noticeable, temporary weight increases, often presenting as swelling in the lower legs and ankles.
Corticosteroids fundamentally change how the body processes and stores energy from food. They promote gluconeogenesis—the creation of glucose from non-carbohydrate sources—leading to elevated blood sugar levels. This sustained high glucose level contributes to insulin resistance, making it harder for the body to utilize sugar effectively and promoting the storage of excess energy as fat.
The stored fat is often redistributed to specific areas of the body, a phenomenon known as lipodystrophy. This characteristic side effect moves fat away from the limbs and concentrates it in the face, neck, and torso. This can result in a “moon face” appearance and increased fat deposits around the abdomen and the back of the neck (“buffalo hump”). These changes can occur even with moderate overall weight gain, making weight gain a common adverse effect reported by up to 70% of people on long-term systemic steroids.
Strategies for Minimizing Weight Fluctuation
Individuals concerned about weight gain while undergoing corticosteroid treatment have several practical strategies to manage this side effect. Since fluid retention is a major contributor to initial weight increase, reducing sodium intake helps minimize bloating and swelling. Limiting high-salt processed foods is advised to help the body maintain a proper balance of water and electrolytes.
Managing the increased appetite requires a focus on food choices and portion control. Selecting nutrient-dense, low-calorie options like fresh fruits, vegetables, and lean proteins can satisfy hunger without excessive caloric load. Eating smaller, more frequent meals throughout the day can also help regulate blood sugar and curb the urge to snack excessively.
Regular physical activity is an important component of a mitigation strategy, as exercise helps burn excess calories and counter metabolic slowdown. Even light activities like walking, swimming, or cycling are beneficial for maintaining a healthy weight. Finally, maintain open communication with the prescribing physician about any concerns. They may be able to adjust the dosage or explore alternative treatment schedules to reduce the systemic impact of the drug.