Nature's Way Bitter Orange extract
The immature bitter orange ( Citrus aurantium ) has been used for thousands of years in ancient Chinese medicine. Nature's Way Bitter Orange Extract provides high levels (6%) of the key compound, synephrine, which has been the focus of study for its thermogenic properties. High doses of bitter orange can increase heart rate and increase metabolism. We suggest at first to only use half a capsule until you find out how this product works with your system. Use bitter orange by itself without other supplements or medicines the first couple of times you try it. Do not use bitter orange if you have a heart condition or taking medicines for your heart or blood pressure.

 

Bitter Orange supplement, FREE Diet Rx bottle, and hundreds of natural supplements are available for sale
Supplement Facts:
Bitter Orange - 450 mg  - Citrus Aurantium dried extract (fruit)

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Benefits of Diet Rx
All natural appetite suppressant, decreases appetite so you eat less
Helps you maintain healthy blood sugar levels
Helps you maintain healthy cholesterol and lipid levels
Provides a variety of antioxidant from two dozen herbs and nutrients
Provides healthy fiber
Improves energy
Balances mood
Improves mental concentration and focus
Improves will power and choice of food selection

Bitter orange extract side effects
Increased body temperature may occur as the bitter orange dose is increased. Drink plenty of cold water. Bitter orange may increase risk of heart irregularities and increase blood pressure. Discuss with your physician if you are taking medicines or have a chronic health condition. Long term effects or potential harm from high dose of bitter orange ingestion is still not fully understood.

Possible association of acute lateral-wall myocardial infarction and bitter orange supplement.
Nykamp DL. School of Pharmacy, Mercer University, Atlanta, GA
Ann Pharmacother. 2004 May;38(5):812-6.
To report a possible incidence of acute lateral-wall myocardial infarction (MI) coinciding with the use of a Citrus aurantium L. ( bitter orange ) containing dietary supplement in a patient with undetected coronary vascular disease. A 55-year-old white woman presented to the emergency department with symptoms of dull aching shoulder and chest pain. A review of medications during cardiac rehabilitation revealed the patient had ingested a multicomponent dietary supplement for weight loss containing 300 mg of bitter orange (Edita's Skinny Pill) for the past year. Although the patient's past medical history did not include hypertension, coronary disease, or hyperlipidemia, an arteriogram revealed a lesion in the left main coronary artery. She did have a smoking history. She was diagnosed with acute lateral-wall MI and hospitalized for 4 days. Although consumers are becoming more aware of the serious adverse effects secondary to products containing ingredients such as Ma huang and ephedra, reports involving other ingredients are increasing. Bitter orange or synephrine, found in bitter orange, has been associated with adverse cardiovascular reactions. Based on the Naranjo probability scale, Bitter orange is possibly associated with this cardiovascular event. The use of bitter orange-containing supplements may present as a risk for cardiovascular toxicity; however, additional studies/case reports are needed to validate this conclusion.

Bitter orange opinion
Bitter orange extract may help one lose weight, but caution is advised. Use the least amount possible and take breaks from use. Do not take bitter orange daily for many weeks or months without a break. Do not use bitter orange if you have heart disease or taking strong medicines.

Other weight loss options to consider
Green tea extract is a good option
Hoodia is a cactus plant extract from the Kalahari desert in South Africa that has been getting a lot of attention lately. 5-HTP is a nutrient that helps curb appetite in some individuals . 5-HTP, by converting into serotonin, can be used temporarily to improve will power and decrease the urge to eat until more established weight loss habits are in place.
Acetyl-l-Carnitine is another option. Some users have reported an all day decrease in appetite when this product was taken before breakfast.
Chitosan supplement has not provided consistent results in research studies and thus is not recommended at this time for weight loss.
Use Stevia as a substitute for sugar.

Bitter orange mechanism of action
The amines in bitter orange stimulate beta-3 cell receptors with less of an effect on other alpha and beta receptors. Stimulation of these beta-3 receptors elicits the breakdown of fat. Simultaneously, this stimulation causes an increase in the metabolic rate – thermogenesis – which burns calories. Bitter orange may also act as an appetite suppressant.

Compounds in Bitter orange extract
Extracts from bitter orange contain a rare combination of five adrenergic amines: synephrine, N-methyltyramine, hordenine, octopamine, and tyramine.

Bitter Orange extract availability
Bitter Orange is sold by raw material suppliers in various extracts, including 4%,6%,8% Synepherin or synephrine. You may find bitter orange extract in certain weight loss products.

Bitter orange review by Ray Sahelian, M.D.
At this point, the safety of bitter orange is still being evaluated, and although it appears to be safer than ephedra, bitter orange extract still carries risks in high doses. The results of studies have sometimes been contradictory. All consumers – particularly those with hypertension, heart disease or other pre-existing conditions – should consult with their health care providers before embarking on a dietary supplement regimen of any sort. A safer approach to appetite suppression is Diet Rx.

Bitter orange Research Update
The results of a study on bitter orange (Citrus aurantium) extract show the natural ingredient has little impact on blood pressure or heart rate. Results from the double-blind, randomized, placebo-controlled, crossover study - conducted by researchers from the University of Connecticut and Hartford (Conn.) Hospital - appear in the Winter 2005 issue of Pharmacotherapy, the journal of human pharmacology and drug therapy. On alternating weeks, the researchers provided test subjects with either the placebo or bitter-orange dried-fruit extract (450 mg standardized to 27 mg of synephrine) with a washout period in between. The team of four doctors and researchers were led by Bokyung Min, Pharm.D., of the University’s School of Pharmacy and the division of Drug Information at Hartford Hospital. Together, they measured the rate-corrected QT (QTc) interval and blood pressure before dosing subjects with bitter orange extract or placebo and then again at one, three, five and eight hours after dosing. The QT interval is part of the normal heart electrical activity seen in an electrocardiogram (EKG). Substances that lengthen this interval are thought to be risk factors for the heart. In the published findings, it was noted that subjects receiving bitter-orange extract versus the placebo had similar post-dose QTc interval, systolic blood pressure, and diastolic blood pressure. All test subjects were healthy adult volunteers. “Bitter orange dried-fruit extract standardized to … synephrine 27 mg did not significantly alter the QTc interval or blood pressure after a single dose was administered,” the researchers wrote in their report. Other recent studies, including a project led by Dr. Christine Haller at the University of California, San Francisco, also showed negligible increases in heart rate and no increase in blood pressure among test subjects, even though subjects in that study received higher concentrations of bitter orange than did those in the Min study. In the Haller study, heart rate increases were reported among all study groups following a meal, which is a natural result of digestion. Dr. Min’s work was supported by an unrestricted educational grant from Pfizer Inc. in Groton, Conn. The report is entitled “Absence of QTc-Interval-Prolonging or Hemodynamic Effects of a Single Dose of Bitter-Orange Extract in Healthy Subjects.”

A botanical used in some weight-loss products as a substitute for now-banned ephedra may possibly pose health risks of its own. The ingredient is an extract of the Seville orange, known scientifically as Citrus aurantium or bitter orange. According to the authors of the new report, there is no reliable evidence that bitter orange works, but there is evidence that it could raise blood pressure or interact with certain medications. Bitter orange contains a compound called synephrine that, like ephedra, stimulates the central nervous system and may boost metabolism. There have yet to be any reports of serious side effects with bitter orange, but scientists know that synephrine can raise blood pressure and has the potential to raise the risk of cardiovascular complications.

Citrus aurantium ( bitter orange ), an ingredient of dietary supplements marketed for weight loss: current status of clinical and basic research.
Exp Biol Med (Maywood). 2004 Sep;229(8):695-7.
Seville orange (Citrus aurantium, bitter orange) extracts are being marketed as a safe alternative to ephedra in herbal weight-loss products, but bitter orange may also have the potential to cause adverse health effects. Bitter orange contains synephrine (oxedrine), which is structurally similar to epinephrine. Although no adverse events have been associated with ingestion of bitter orange products thus far, synephrine increases blood pressure in humans and other species, and has the potential to increase cardiovascular events. Additionally, bitter orange contains 6',7'-dihydroxybergamottin and bergapten, both of which inhibit cytochrome P450-3A, and would be expected to increase serum levels of many drugs. There is little evidence that products containing bitter orange are an effective aid to weight loss. Synephrine has lipolytic effects in human fat cells only at high doses, and octopamine does not have lipolytic effects in human adipocytes.

Bitter orange as a thermogenic, weight-reduction replacement for ephedra: an overview.
Preuss HG. Georgetown University Medical Center, Washington, DC
J Med. 2002;33(1-4):247-64.
Obesity is a serious health problem throughout the world. More than half of U.S. adults are overweight (61%) and more than a quarter (26%) of U.S. adults are obese. The inability of many individuals to keep their weight in check by diet and exercise has created a need for additional therapeutic means to combat obesity. Despite great effort, the pharmaceutical industry has not come up with the solution; because most weight-loss drugs to date have serious adverse effects to health and well-being. The theory that beta agonists, especially beta 3 agonists, can affect body weight and fat mass is well accepted. Ephedrine has proven time and time again that it is an effective weight loss agent through its ability to increase thermogenesis and quench appetite. However, the publicity concerning adverse reactions has led to its withdrawal from use by many despite the perceived consequences of obesity. Many companies are now substituting Bitter orange extract for ephedra in their formulations. Bitter orange, an agent containing beta agonists, has been reported to aid in weight loss in two studies and increase thermogenesis, at least to some extent, in three studies. Colker et al. (1999) reported that in a double-blind, placebo-controlled, randomized study the subjects receiving a combination of bitter orange, caffeine and St John's Wort, lost significant amounts of total body weight while on a strict diet and exercise. Those in the placebo and control groups who also were on the same restricted diet did not. However, intergroup analysis showed no statistical significance among the weight changes in the three groups. In contrast, the loss of fat mass in the test group was significantly greater compared to the placebo and control groups. Jones describes an open labeled study performed on 9 women. The subjects showed a mean of 0.94 kg lost during the first week when no product was given and 2.40 kg during the second week when a Bitter orange product was taken. Body weight losses were statistically greater during the second week compared to the first week. Since most clinicians would agree that the most weight loss should occur initially coinciding with a greater fluid loss during the first week, these differences are even more remarkable. Three studies reported increased metabolic rates when ingesting Bitter orange products, however, at least two of these studies were acute. At present, Bitter orange may be the best thermogenic substitute for ephedra. However, more studies are needed to establish this definitively. bitter orange peel extract bitter loss orange weight bitter orange synephrine bitter.

Bitter Orange product update
Nutratech, Inc., a supplier of ingredients to the weight-loss and sports nutrition markets, has announced that its proprietary bitter orange-based ingredient, Advantra ZR, contains p-synephrine, a stable isomer of the synephrine alkaloid, but does not contain m synephrine, which has the potential for raising blood pressure.

Zhi shi is the immature dried fruit of citrus aurantium, also known as bitter orange.

This bitter orange page was last updated February 2008.

bitter orange