It is claimed that pendants provide protection from electromagnetic radiation (e.g. from computers and mobile phones). Three experiments tested the effectiveness of such a pendant’s effect as a bioelectric shield. In the first experiment, 12 subjects that work with computers wore shields (six real, six sham) for several weeks and were regularly tested for hand strength and mood changes. Both types of shield increased calmness, but the real shields did not have a greater effect than the sham pendant. In two further studies (in each n = 40) hand strength was measured at baseline, with mobile phone, and with mobile phone and bioelectric or sham shield. The shields did not differ in their effects. Both studies showed a significant correlation between the change in strength with and without the shield and subjects’ scores on a questionnaire concerning their belief in and use of alternative therapies. The authors concluded that the shields appear to produce a measurable placebo effect but are otherwise ineffective.