There is a study, apparently supported by Integrative Health Technologies, Inc and Nutratech, Inc for a product called Advantra V, that has a surprisingly enough findings to warrant talking about (not all industry supported studies are by default biased or “those scientists sold out to big money” results). It is followed up by a discussion on how synephrine might be of great use to helping burn fat in greater proportion to burning carbohydrates during exercise. We might just have a winner here for increasing resting metabolism and fat loss!

Our first study uses p-synephrine (scientific name for synephrine) in groups 10 per treatment group. They thankfully made the study double-blind (so no researcher bias affecting the participants) and placebo-controlled (no psychological effects from the participants knowing if they got the real supplement or a placebo). They were measured for Resting Metabolic Rate (RMR) before injection, and 75 minutes after injection (all put in a V8 juice). RMR is important because the majority of calories YOU burn daily is from that total, almost NEVER from exercise (unless doing obscene amount of exercise; something called “NEET” is a whole other can of worms).

The placebo group actually had a RMR 30 calories lower 75 minutes later! Not good after injecting a calorie load from a juice!

The group receiving p-synephrine (50mg) had a 65 calorie increase compared to the placebo (an extra .56 pounds of bodyfat burned per month). When combined with 600 mg narnigin ( a grapefruit extract that helps drugs and supplements absorb into the body better), there was a 129 calorie increase in RMR! Over a month that is an extra 1.1 pounds of body fat, a big gain for anyone who has ever tried to lose body fat seriously! What’s even more insane is when they combined those two with 100 mg hesperidin - it increased to 183 calories in RMR… close to 1.6 pounds of body fat per month! Further increases in hesperidin to 1000 mg cut it down to 79 calorie increase in RMR, so definitely too much for a good thing is the lesson here as in everything.¹ What's fantastic, compared to a fat-burning stimulant like ephedrine which has some nasty side effects, is that there were no changes in blood pressure or heart rate (the increased heart rate being much of ephedrine's source of more burned calories).

The other study on synephrine worth looking at is one that measured increases in fat oxidation (using fat for fuel) and lessening of carbohydrate oxidation (using carbs for fuel) DURING exercise (and thankfully double-blind and placebo-controlled also). No greater amount of total calories were burned (which would show like the previous study it is not stimulating along the same biological pathway something like ephedrine is doing, or at least not detectably), but helps the body move towards using fat for energy during exercise rather than carbohydrate.² Please note this was on a cycle ergometer, so it was endurance exercise, so this use of synephrine would most likely be best for your fat burning cardio session or when you do your endurance training.

No significant changes occurred in electrocardiograms, heart rates, systolic blood pressure, blood chemistries, or blood cell counts at any time point in either control or p-synephrine treated group. A small (4.5mmHg) decrease in diastolic blood pressure occurred in the p-synephrine treated group at 60 minutes. No adverse effects were reported.

Several years ago there was worry that synephrine had possible heart-damaging effects. Do not worry:

A recent review in a prestigious medical journal concluded that "bitter orange extract and p-synephrine are safe for use in dietary supplements and foods at the commonly used doses."³
So have no fear!

Give synephrine a try, it might be a supplement with some real calorie burning and nutrient partitioning effects that is worth giving a go!