The FDA is said to have of late instituted a crack down on weight loss supplements as a result of very bad uncomfortable side effects and even death associated with some dietary supplements including ephedra. The ban on ephedra goods resulted to the roll-out of so-called ephedra free weight loss supplements, these too have been shown to yield their very own fair share of problems and they too could possibly be destined to exactly the same fate as ephedra.

These ephedra free drugs are said to result in an increase in heart rate and a couple other side effects on healthy men and women according to a health professional connoisseur who took part in the study.

The inquiry performed through the University of California at Berkeley was the initial one to check out the health effects of reformulated weight loss supplements. Among the things investigated 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 large figure of unwanted weight loss product manufactures have changed to extracts of bitter orange. The USB study included 20 healthy volunteers, who received single doses of a weight loss supplement or a placebo.

The diet supplements tested in the research project were Xenadrine EFX and Advantra Z, each of which contains bitter orange extracts. The used drug was shown to produce a rise in cardio pulse rate of up to 16 beats in one minute. The Thermogenic Xenadrine EFX in particular was shown to rev up heartbeat by 13 per cent, something which makes it almost identical in performance to ephedra.

Bitter orange extracts contain synephrine, a part specific to over 90% of citrus fruits but found in greater concentrations in fruits such as Sour orange, Zhi shi and bitter orange and which can be popularly used as a relief medication in the treatment of respiratory tract congestion and high blood pressure. Xenadrine EFX includes a stimulant in the constituent, usually caffeine. The amount of caffeine is Xenadrine is approximated to be very similar to 3 coffee cups. This is the ingredient to blame for the increase in blood pressure and individuals using this product are informed against over dosage.