The FDA is said to have as of late instituted a crack down on weight loss supplements as a result of severe uncomfortable side effects and even death linked to some dietary supplements including ephedra. The ban on ephedra products resulted to the roll-out of so-called ephedra free weight loss supplements, these too are said to yield their own fair share of troubles and they too might be destined to a similar fate as ephedra.

These ephedra free drugs have been shown to bring about a rise in heartbeat and a few other unintended effects on healthy folks based on a health expert who took part in the research.

The study performed with the University of California at Berkeley was the best one to go into the health effects of reformulated weight loss supplements. One of the things tested for included blood pressure and pulse rate of volunteers who were given reformulated weight loss supplements made out of extracts of bitter orange.

Since the ban slapped on ephedra by FDA, a growing figure of weight loss product manufactures have turned to extracts of bitter orange. The USB research engaged 20 healthy volunteers, who were given individual doses of a weight loss supplement or a placebo.

The diet supplements used in the research were Xenadrine EFX and Advantra Z, each of which is made up of bitter orange extracts. The applied drug was shown to effect a slight increase in cardiovascular pulse rate as high as 16 beats in one minute. The Thermogenic Xenadrine EFX especially was shown to rev up heart rate by 13 per cent, something which makes it almost similar in performance to ephedra.

Bitter orange extracts contain synephrine, a ingredient specific to over 90% of citrus fruits but found in larger concentrations in fruits such as Sour orange, Zhi shi and bitter orange and that is popularly used as a remedy in the management of respiratory tract congestion and hypertension. Xenadrine EFX features a stimulant in the constituent, usually caffeine. The amount of caffeine is Xenadrine is estimated to be the equivalent of 3 coffee cups. This is the element the cause the surge in blood pressure and affected individuals using this product are informed against over dosage.