How long do perineural injections last? Understanding Pain Relief Duration

October 8, 2025 •

4 min read

Pain relief from the first perineural injection, a treatment using a dextrose solution, can last from a few hours up to four days. However, the therapy is designed for a cumulative, long-term effect on chronic pain, with repeated treatments extending the duration of relief significantly.

Quick Summary

The duration of relief from a single perineural injection is short, lasting hours to a few days. The therapy's goal is lasting pain resolution through a series of treatments that promote nerve healing. Multiple factors, including the condition and injection substance, influence the overall outcome.

Key Points

Initial Relief is Temporary: The first perineural injection offers immediate relief that typically lasts for a few hours to four days.
Long-Term Relief is Cumulative: Lasting pain resolution is achieved through a series of repeated treatments, not a single injection.
Dextrose is the Key Agent: The injections typically use a dextrose solution, which works to reset nerve function and reduce neurogenic inflammation.
Requires Multiple Sessions: A standard treatment course involves 4 to 10 sessions, usually administered weekly, for cumulative healing.
Factors Influence Duration: The longevity of relief is affected by the chronicity and severity of the pain, the patient's individual response, and consistency of treatment.
Regenerative vs. Symptomatic: Perineural therapy is a regenerative approach that aims for long-term healing, distinguishing it from temporary pain blockers or anti-inflammatory steroid shots.

What are Perineural Injections?

Perineural Injection Therapy (PIT), also known as neural prolotherapy, is a non-pharmacological and minimally invasive treatment for chronic nerve pain. It involves injecting a buffered dextrose solution, or sometimes other substances, just under the skin to target inflamed and sensitive superficial nerves. This approach addresses neurogenic inflammation, where irritated nerves misfire and release pain-inducing substances, causing persistent pain. Unlike temporary pain relievers, PIT aims to reset and restore the nerve's normal function over time.

Initial vs. Cumulative Effects: The Progression of Relief

The most important distinction to understand is that the relief from a single perineural injection is not permanent. It is merely the first step in a regenerative process intended to produce lasting results.

Initial Treatment: After the very first session, patients often experience rapid pain relief, sometimes within seconds. This initial relief is temporary, typically lasting between a few hours and four days. For some, this immediate effect is a confirmation that the correct nerve has been identified and treated.
Subsequent Treatments: The key to long-lasting relief lies in consistency. Patients typically undergo a series of injections, usually spaced one to four weeks apart. With each consecutive treatment, patients report a gradual improvement in their symptoms. The duration of pain relief after each session lengthens, and the intensity and frequency of the pain gradually decrease.
Long-Term Outcome: The ultimate goal of a full course of PIT is a complete resolution of pain and the restoration of normal function, rather than just masking symptoms. Many patients report significant, long-term relief after completing the full treatment protocol, which can range from 4 to 10 sessions.

Key Factors Influencing Perineural Injection Duration

Several factors can influence the duration of both the initial relief and the overall effectiveness of perineural injections:

The Injected Solution: The type of solution used plays a direct role. While a low-concentration dextrose solution is most common, some practitioners may also use other solutions or combine therapies. The mechanism of dextrose is not a temporary nerve block but rather a regenerative process that calms irritated nerves.
Chronicity of Pain: The longer a patient has experienced chronic pain, the more sessions may be needed to achieve a lasting effect. Long-standing inflammation and nerve sensitization require more time and treatment to reset.
Patient Response: Every individual's body responds differently. Some patients see more rapid improvement, while others require a more extended treatment plan. Those taking certain medications, such as opioids, may also see a less pronounced response to dextrose injections, as these substances can interfere with the therapy's mechanism.
Adherence to Treatment Plan: Consistent follow-up treatments are crucial for building upon previous sessions and achieving long-term resolution. The healing effect is cumulative and depends on completing the full course of injections.
Condition and Location: The specific condition being treated (e.g., sciatica, carpal tunnel) and the location of the injection can influence outcomes. The complexity of the nerve pathology will dictate the number of sessions and the potential for a complete cure.

Perineural Injections vs. Other Injections: A Comparison

It is important to differentiate perineural injections from other types of pain injections, as their mechanisms and objectives vary significantly.


Feature	Perineural Injection (Dextrose)	Temporary Nerve Block (Anesthetic)	Corticosteroid Injection
Primary Agent	Dextrose solution	Local Anesthetic (e.g., lidocaine, bupivacaine)	Steroid medication (e.g., Decadron)
Mechanism	Targets nerve membranes to reset function and promote healing	Numbing agent blocks nerve signals temporarily	Powerful anti-inflammatory effect
Duration (Single Shot)	Hours to days initially, cumulative with series	Hours to ~36 hours, temporary relief	Weeks to several months, temporary relief
Overall Goal	Lasting resolution and nerve regeneration	Short-term pain relief	Short-term reduction of inflammation
Risks/Side Effects	Minimal; bruising, temporary soreness	Weakness, numbness, low risk of nerve injury	Potential long-term tissue damage

The Treatment Course for Lasting Relief

A typical treatment protocol involves multiple sessions to achieve a lasting effect. For superficial injections, a series of 6 to 8 treatments, administered weekly, is common. For more severe or deeper nerve issues, additional sessions may be required. With each session, the goal is not just to provide temporary relief but to encourage the body's natural healing processes and restore proper nerve function. The number of injections required ultimately depends on the individual's condition and how their body responds to the therapy.

Conclusion: Achieving Sustainable Pain Management

While the pain-relieving effects of a single perineural injection may last for only a few days, the long-term benefits are cumulative and potentially permanent. The therapy's objective is to address the underlying cause of chronic pain by resetting and healing irritated nerves, rather than simply masking symptoms. By completing a full course of treatment, patients can progress from short-term relief to a significant reduction or even full resolution of their chronic pain. This regenerative approach offers a compelling alternative to temporary solutions like anesthetic nerve blocks or potentially damaging steroid injections, providing a path to lasting pain management for many individuals. Research continues to explore the mechanisms and effectiveness of this promising therapy. For more information, the National Institutes of Health (NIH) features articles on related regenerative injection techniques.

Frequently Asked Questions

A perineural injection typically uses a dextrose solution to promote nerve healing and reset nerve function over time. A traditional nerve block uses a local anesthetic, like lidocaine, to temporarily numb the area and block pain signals for a shorter duration.

The goal of a full course of perineural injection therapy is to provide lasting, and potentially permanent, relief by addressing the underlying nerve irritation. This is achieved through a series of treatments that accumulate regenerative effects.

Most patients require a series of 4 to 10 sessions, spaced about one to four weeks apart, to achieve significant and lasting pain relief. The exact number depends on the individual condition and response.

Side effects are minimal and typically include temporary bruising, soreness, or swelling at the injection site. Since dextrose is a naturally occurring substance, allergic reactions are very rare.

In many regions, including parts of the U.S. and U.K., insurance companies may consider perineural injection therapy "unproven" and may not cover the treatment. Patients should check with their provider for specific coverage details.

Many patients feel immediate pain relief, sometimes within seconds or minutes, after a perineural injection. However, this initial relief is temporary, and the duration lengthens with subsequent treatments.

The injections are performed with very thin needles, similar to those used for acupuncture or a TB shot, and are generally well-tolerated. Patients may feel a mild prickling sensation.

Yes, perineural injections can be combined with other therapies, such as physical therapy, shock-wave therapy, or cold laser therapy, to accelerate healing and improve overall outcomes.