That question has been the focus of numerous academic studies and by those who are just plain sceptical of the claimed beneficial effects.
Some of the studies seem to suggest that just maybe there could be some advantage from wearing magnets close to the skin. However, you will probably find the words "placebo effect" somewhere in the article.
Yes, you do see manufacturers claiming pain relief for arthritis, back, wrist, shoulder etc. It is these claims that those writing the research papers find difficult to support and perhaps they never will.
There was a time when the medical profession had difficulty with the effectiveness of osteopathy. Now many doctors refer their patients to an osteopath or similar. Maybe you cannot compare the two practices but you have to put yourself in the position of a person in distress who has tried the standard medical treatments. If these treatments are not proving effective should the sufferer just sit back and accept the hurt or try to improve their standard of life? Those who in the past have put their hand in their pockets to be treated by an osteopath, food allergy expert etc. know the answer to that question.
I know of one person who wore a small magnetic wrap above her knee to try to relieve the terrible pain she felt in her leg when walking. Did the pain ease? No, in fact, it became worse and she had to stop wearing it. It transpired that the lady had a blocked vein and it was that circulatory problem that was causing the discomfort. Did the discomfort increase because the magnets were attempting to boost the blood flow where there was a blockage?
Another lady bought a magnetic bracelet, put it on her right wrist and started to feel unwell. She transferred it to her left wrist and the problem ceased. Later she tried to wear it on her right wrist but again she felt unwell.
In both the cases were the magnets having an effect on the body? They were not part of any controlled clinical trials and so we will never know. It is doubtful whether clinical trials would prove beyond question that they were. All that can be said is that the magnets did appear to be having some effect.
What can we conclude from the above? If you have a problem and think magnetic therapy might help, why not give it a try? If you are a pregnant lady or if you have a pacemaker then definitely do not use magnetic products. As ever, if you have any doubts, firstly consult your doctor.
There is some beautiful magnetic jewellery for sale. Even if you are a doubter, why not just get pleasure from the bracelet or whatever for what it is - a pleasant and striking piece of jewellery.