What are the benefits and risks of Botox-A injection for treating persisting neck pain?

Key messages

• Compared to a saline placebo (an inactive sterile water injection), Botox-A may provide a slight short-term improvement in pain (6%) which does not extend to the long term. People may report treatment success (20%) in both the short and long term. There may be no improvement in people's ability to carry out everyday activities, or in health-related well-being. There may be a 16% higher chance of mild unwanted effects such as soreness at the injection site, muscle fatigue, general soreness, or headache lasting up to three weeks.

• Manufacturers of Botox A funded some of the research, which may have influenced the studies and overestimated the benefit of this treatment.

• Future studies should be larger, use better methods and last longer. The studies should be independently funded.

What is Botox-A?

Botox-A is a neurotoxin (chemical substance) that temporarily weakens or paralyses certain muscles or blocks certain nerves. It is injected into trigger points. Trigger points are defined as very sensitive knots within taut bands of skeletal muscles that can produce pain felt in a different body region other than where the problem is, also known as referred pain.

Botox-A might help persistent neck pain by reducing muscle tension and spasm, and related pain signals.

People might experience unwanted effects that are mild and short-lived, such as small areas that are sore or tender. Rare events like severe allergic reaction that leads to death can occur.

What did we want to find out?

For people with persisting neck pain, we wanted to find out if Botox-A was better than a saline placebo (inactive sterile water) injection at improving:

• pain;

• physical function (ability to carry out everyday activities);

• health-related well-being;

• how successful people felt their treatment was;

• patient satisfaction.

Neck pain may include symptoms originating from the neck that are felt in the head, upper back, and arm. Neck pain could be with or without associated myofascial pain (sensitive knots with taut muscle bands), degenerative changes (wear and tear changes), whiplash-associated disorders, and headaches stemming from the neck.

We also wanted to know if Botox-A caused any unwanted effects.

What did we do?

We searched for studies that looked at Botox-A medical injections compared to a placebo. We compared and summarised the results of the studies and rated our confidence in the evidence, based on factors such as study methods, varied treatment doses, how similar the studies' results were, and how big the studies were.

What did we find?

We found 16 studies with 855 people with persistent neck pain (associated myofascial pain, whiplash-associated disorders, or headaches stemming from the neck). They were aged 18 to 80 years and more than half (64%) were women. Most studies lasted from 3 to 12 weeks; only two studies lasted 24 weeks or longer. They took place in pain management clinics in hospitals, surgery departments, and universities in North and Central America, Europe, the Middle East, and Asia. Most studies reported short-term results (up to three months). The total Botox-A dose ranged from 10 to 400 units, administered across 1 to 10 trigger points.

Main results

In people with persistent neck pain treated with Botox-A compared with placebo:

• there may be a slight short-term improvement in pain (6%; 12 studies, 393 people), but these changes may not make a real difference in daily life. The observed improvement in pain may not be sustained in the long term;

• there may be little to no benefit for daily physical function (2%; 3 studies, 76 people) or health-related well-being, but we are not confident in this evidence;

• there may be a small improvement in both in the short term (20%; 1 study, 19 people) and long term (20%; 1 study, 31 people) for participant-reported treatment success;

• the risk of mild unwanted effects such as injection site soreness, muscle fatigue, muscle soreness, or general headache may be 16% higher when compared to placebo. These unwanted effects may last up to three weeks.

No studies evaluated patient satisfaction.

What are the limitations of the evidence?

Our confidence in the evidence is limited for several reasons.

• Most of the evidence was short-term, so we don’t know what the long-term effects are.

• Most studies were funded by pharmaceutical companies, so they may overstate the benefits of Botox-A.

• The methods used in several studies likely introduced sources of error, including how they divided people into treatment groups and the possibility that people in the studies knew which treatment they were getting.

• Studies used different doses of Botox-A, which makes it difficult to compare their results.

Future studies should be independently funded, use more robust methods and present long-term results.

How up to date is this evidence?

The evidence is up to date to March 2026. This review updates the previous version published in 2011 with 10 new studies. We now find a potentially slight improvement in pain.