There seems to be no end to the dangers of dietary supplements. Ephedra-containing dietary supplements, which can raise blood pressure and heart rate, were banned by the FDA in 2004 because they were associated with an increase in heart attacks, strokes, and deaths.

Now, a new study has found that two popular, ephedra-free weight loss supplements -- Advantra Z and Xenadrine EFX -- can increase heart rate and blood pressure as much as the supplements that contained ephedra. These adverse effects have been linked to the bitter orange contained in these supplements. Xenadrine EFX also contains caffeine. In healthy people both supplements increased heart rate by 11 beats to 16 beats per minute, and Xenadrine EFX raised blood pressure by 7 percent to 12 percent.

Everyone should avoid these weight-loss supplements, especially people who have heart disease or borderline high blood pressure.