Efficacy and Safety of Ephedra and Ephedrine for Weight Loss and Athletic Performance

Abstract

ContextEphedra and ephedrine sometimes are used for weight loss or enhanced athletic performance, but the efficacy and safety of these compounds are uncertain.ObjectiveTo assess the efficacy and safety of ephedra and ephedrine used for weight loss and enhanced athletic performance.Data SourcesWe searched 9 databases using the terms ephedra, ephedrine, adverse effect, side effect, efficacy, effective, and toxic. We included unpublished trials and non–English-language documents. Adverse events reported to the US Food and Drug Administration MedWatch program were assessed.Study SelectionEligible studies were controlled trials of ephedra or ephedrine used for weight loss or athletic performance and case reports of adverse events associated with such use. Eligible studies for weight loss were human studies with at least 8 weeks of follow-up; and for athletic performance, those having no minimum follow-up. Eligible case reports documented that ephedra or ephedrine was consumed within 24 hours prior to an adverse event or that ephedrine or an associated product was found in blood or urine, and that other potential causes had been excluded. Of the 530 articles screened, 52 controlled trials and 65 case reports were included in the adverse events analysis. Of more than 18 000 other case reports screened, 284 underwent detailed review.Data ExtractionTwo reviewers independently identified trials of efficacy and safety of ephedra and ephedrine on weight loss or athletic performance; disagreements were resolved by consensus. Case reports were reviewed with explicit and implicit methods.Data SynthesisNo weight loss trials assessed duration of treatment greater than 6 months. Pooled results for trials comparing placebo with ephedrine (n = 5), ephedrine and caffeine (n = 12), ephedra (n = 1), and ephedra and herbs containing caffeine (n = 4) yielded estimates of weight loss (more than placebo) of 0.6 (95% confidence interval, 0.2-1.0), 1.0 (0.7-1.3), 0.8 (0.4-1.2), and 1.0 (0.6-1.3) kg/mo, respectively. Sensitivity analyses did not substantially alter the latter 3 results. No trials of ephedra and athletic performance were found; 7 trials of ephedrine were too heterogeneous to synthesize. Safety data from 50 trials yielded estimates of 2.2- to 3.6-fold increases in odds of psychiatric, autonomic, or gastrointestinal symptoms, and heart palpitations. Data are insufficient to draw conclusions about adverse events occurring at a rate less than 1.0 per thousand. The majority of case reports are insufficiently documented to allow meaningful assessment.ConclusionsEphedrine and ephedra promote modest short-term weight loss (≈0.9 kg/mo more than placebo) in clinical trials. There are no data regarding long-term weight loss, and evidence to support use of ephedra for athletic performance is insufficient. Use of ephedra or ephedrine and caffeine is associated with increased risk of psychiatric, autonomic, or gastrointestinal symptoms, and heart palpitations.

Metabolic and physiological effects of ingesting extracts of bitter orange, green tea and guarana at rest and during treadmill walking in overweight males

“…5 The b3-receptor seems to be the most abundant beta subtype in human brown adipocytes and is thought to play a key role in the lipolytic and thermogenic effects of adrenergic agents, 2,33 without exerting an effect on those receptors responsible for cardiovascular control. 2 These effects might be consistent with the results of study 1 in terms of the observed increase in plasma NEFA minus any significant changes in heart rate or blood pressure.…”

“…Indeed, several commercially available supplements, containing ephedrine and ephedra, have been used for this purpose with some success. 5 However, recent reports have identified numerous possible problems with these supplements including an increased risk of psychiatric, autonomic and gastrointestinal symptoms, as well as heart palpitations. 5 These problems have led to the development of non-ephedra-based supplements containing bitter orange (also known as citrus aurantium), green tea-leaf extract and guarana (Gx).…”

“…7 Bitter orange ingestion is thought to result in catecholamine release in the vicinity of b3-adrenoreceptors located primarily in the adipose tissue and liver. As a result, bitter orange ingestion is purported to promote weight loss and increased thermogenesis, 5 while having a minimal effect on blood pressure and heart rate. 8 Green tea-leaf extract contains several polyphenolic compounds that help to prevent the degradation of noradrenaline.…”

“…Measurements: In study 1, subjects completed 7 h supine rest with baseline measures taken during the first hour, with expired gases, blood pressure, heart rate and venous blood being collected every 30 min for the remaining 6 h following ingestion of Gx or P. In study 2, subjects exercised for 60 min at 60% heart rate reserve following ingestion of Gx or P 1 h previously. Venous blood samples were collected twice at rest and at 5,10,15,20,30, 40, 50 and 60 min, with expired gas measurements taken at 4, 9, 14, 19, 29, 39, 49 and 59 min. In both studies, venous blood was analysed for NEFA, glycerol, glucose and lactate concentrations, while expired gases were used to calculate ATP production from carbohydrate and NEFA, as well as the total substrate utilised.…”

Addressing the potential risks associated with ephedra use: a review of recent efforts

“…The reviewers could not determine the extent to which ephedra enhanced athletic performance, due to insufficient evidence. 10 The death of Baltimore Orioles' pitcher Steve Bechler in February 2003 propelled concerns related to ephedra use into the national spotlight. Bechler's body temperature rose to 108 degrees during a spring training workout, a few hours after he took a large dose of a supplement that contained ephedra.…”