Epidural steroid injections typically provide pain relief lasting three to six months, though results vary widely. Some people get relief for just a few weeks, while others feel significantly better for up to 12 months. How long your injection lasts depends on what’s causing your pain, how severe it is, and how your body responds to the steroid.
When Relief Starts and How Long It Lasts
The steroid begins working within one to three days, though some people need up to a full week to feel the benefits. This delay happens because the medication doesn’t simply numb pain the way a local anesthetic does. Instead, it works by reducing inflammation around the compressed or irritated nerve roots in your spine. The steroid decreases swelling by making tiny blood vessels in the area less leaky, and it also quiets pain-signaling nerve fibers directly. That process takes time to build.
Once the steroid kicks in, most people can expect meaningful relief for about three months. Studies show reliable pain reduction lasting up to six months in many cases, and some patients report benefits persisting as long as 12 months. But these are averages, and individual experiences vary considerably. A portion of patients get little to no relief at all.
Success Rates by the Numbers
Not everyone responds to an epidural steroid injection, and it helps to have realistic expectations going in. In one large study of patients receiving injections in the lower back, about 39% achieved at least 50% improvement in their pain scores. Roughly one in four patients experienced 80% or greater relief, which is the kind of result that meaningfully changes daily life.
For people with leg pain caused by a herniated disc specifically, the odds are somewhat better. Research shows that up to 70% of these patients felt at least 50% better at the one- to two-month mark. By 12 months, about 40% still reported improvement. That dropoff is expected. Epidural steroid injections are not a cure. They reduce inflammation temporarily, which buys time for the underlying problem to heal on its own or for you to make progress with physical therapy.
What Affects How Long Your Injection Lasts
The single biggest factor is what’s causing your pain. Herniated discs tend to respond better than spinal stenosis, largely because disc herniations involve a strong inflammatory component that steroids are well suited to calm. Stenosis, where the spinal canal has physically narrowed, involves more mechanical compression. The steroid can still help with any inflammation around the nerve, but it can’t widen the canal itself, so relief tends to be shorter-lived.
Other factors that influence duration include how long you’ve had pain before the injection (newer pain generally responds better), whether the injection is placed precisely at the right spinal level, and your overall health. People with diabetes, for example, may metabolize the steroid differently, and the injection can temporarily raise blood sugar levels.
How Many Injections You Can Get
If your first injection provides meaningful relief, a repeat injection is reasonable once the effects wear off. Current guidelines from the Spine Intervention Society support an initial injection followed by up to two additional injections for patients who respond well, spaced at intervals of three weeks to three months within a six-month period. That works out to a maximum of three injections in six months for most treatment plans.
The key principle is that repeat injections should only be offered to people who experienced clear, measurable improvement from the first one. If your initial injection didn’t help, getting another one is unlikely to produce a different result. Each injection also needs enough spacing to allow your adrenal glands to recover, since the steroid temporarily suppresses your body’s natural cortisol production. Beyond the initial six-month treatment window, there’s no firm consensus on long-term dosing schedules, and most physicians take a conservative approach.
What to Expect After the Procedure
The injection itself takes about 15 to 30 minutes. You’ll likely receive a local anesthetic along with the steroid, which can provide immediate but short-lived numbness in the area. As that wears off over a few hours, your pain may actually return or temporarily worsen before the steroid takes effect. This “flare” period is normal and can last one to two days.
Most people return to normal activities within 24 to 48 hours, though you’ll typically be told to avoid strenuous exercise for a few days. The window of reduced pain is best used actively. Physical therapy, stretching, and gradual strengthening during this period can extend your results beyond what the injection alone would provide, because you’re addressing the underlying mechanics that contributed to your pain in the first place.
If your pain returns after the injection wears off and you’ve exhausted your reasonable number of repeat injections without lasting improvement, that’s usually the point where your doctor will discuss other options, ranging from different types of nerve procedures to surgical evaluation depending on your specific diagnosis.