What is known from the scientific evidence about the effectiveness of magnets in treating pain?
Overall, the research findings so far do not firmly support claims that
magnets are effective for treatment of pain.
Findings from Reviews of Scientific Studies
Reviews take a broad look at the findings from a group of individual research
studies. Such reviews are usually either a general review,
a systematic review, or a meta-analysis.
There are not many reviews available on CAM uses of magnets to treat pain.
Appendix II provides examples of six reviews
published from August 1999 through August 2003 in English in the National
Library of Medicine's MEDLINE database.
- Often, these reviews
compared what is known from the clinical trials of magnets for painful
conditions to what is known from conventional treatments or from other
CAM treatments for the same condition(s).
- One review found
that static magnetic therapy may work for certain conditions but that
there is not adequate scientific support to justify its use.1
- Three reviews found
that electromagnetic therapy showed promise for the treatment of some,
but not all, painful conditions, and that more research is needed.9,19,20
One of these reviews also looked at two randomized clinical
trials (RCTs) of static magnets.9
One reported significant pain relief in subjects using magnets, but
the other did not.
- Another review
concluded that TMS has an effect on the central nervous system that
might relieve chronic pain and, therefore, should be studied further.14
- The remaining review
found no studies on magnets for neck pain and stated that rigorous studies
are much needed.21
- It is important
to note that the reviews pointed out problems with the rigor of most
research on magnets for pain.9,14,19,20
For example, many of the clinical trials involved a very small number
of participants, were conducted for very short durations (e.g., one
study applied a magnet a total of one time for 45 minutes), and/or lacked
a placebo or sham group for
comparison to the magnet group.19,20
Thus, the results of many trials may not be truly meaningful. Most reviews
stated that more and better quality research is needed before magnets'
effectiveness can be adequately judged.
The studies in Appendix III give an overview
of scientific research from 15 RCTs published in English from January
1997 through March 2004 and cataloged in the National Library of Medicine's
MEDLINE database. These trials studied CAM uses of static magnets or electromagnets
for various kinds of pain.
- The results of
trials of static magnets have been conflicting. Four of the nine static
magnet trials analyzed found no significant difference in pain relief
from using a magnet compared with sham treatment or usual medical care.7,8,22,23
Four trials did find a significant difference, with greater benefit
seen from magnets.24-27 The remaining trial
compared only a weaker strength magnet to a stronger magnet, and found
benefit from both (there was no difference between groups in how much
- Trials of electromagnets
yielded more consistent results. Five out of six trials found that these
magnets significantly reduced pain.10,11,17,18,29
The sixth found a significant benefit to physical function from using
electromagnets, but not to pain or stiffness.30
- Some study authors
suggested that a placebo effect could have been responsible for the
pain relief that occurred from magnets.22,30
- While criticizing
many of these studies, it is fair to say that testing magnets in clinical
trials has presented challenges. For example, it can be difficult to
design a sham magnet that appears exactly like an active magnet. Also,
there has been concern about how many participants have tried to determine
whether they have been assigned an active magnet (for example, by seeing
whether a paperclip would be attracted to it); this knowledge could
affect how meaningful a trial's results are.