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Eph3.8
Ephedrine Research
Mostly mechanism / observationalLimited safety
6 peer-reviewed studies
What the evidence says
Mostly mechanism / observational
Most Ephedrine studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from medium-quality meta-analyses and randomised trials published 1992–2003 with a typical study size of 167 participants.
Based on 6 studies · 1 meta-analysis · 3 RCTs · 377 total participants
Confidence
Moderate
By outcome
Weight & fat loss
Mostly mechanism / observational6 studies
Psychiatric & CNS effects
Mostly mechanism / observational4 studies
Safety profile
Mostly mechanism / observational4 studies
Cardiovascular harm
Mostly mechanism / observational3 studies
Older research base
Newest study from 2003 · Latest meta-analysis: 2003
199219972003
1Meta-Analysis2003
Ephedrine and ephedra promote modest short-term weight loss (approximately 0.9 kg/mo more than placebo) in clinical trials ... Use of ephedra or ephedrine and caffeine is associated with increased risk of psychiatric, autonomic, or gastrointestinal symptoms, and heart palpitations.
Shekelle PG, Hardy ML, Morton SC, Maglione M, Mojica WA, Suttorp MJ, et al. · JAMA (2003)
The defining meta-analysis (RAND, 52 controlled trials + 65 adverse-event case reports) — the evidence base behind the FDA ban
Ephedrine/ephedra produced ~0.9 kg/month more weight loss than placebo; no trial assessed beyond 6 months and evidence for athletic performance was insufficient
Safety data from 50 trials showed a 2.2- to 3.6-fold increase in the odds of psychiatric, autonomic, or gastrointestinal symptoms and heart palpitations
The ephedrine/caffeine combination is effective, while caffeine and ephedrine separately are ineffective for the treatment of human obesity.
Astrup A, Breum L, Toubro S, Hein P, Quaade F · International journal of obesity and related metabolic disorders (1992)
Pivotal double-blind RCT: 180 obese patients on a 4.2 MJ/day diet given ephedrine/caffeine (20/200 mg), ephedrine (20 mg), caffeine (200 mg), or placebo three times daily for 24 weeks
The ephedrine+caffeine combination produced significantly greater weight loss than placebo from week 8 to 24 (16.6 vs 13.2 kg, P=0.0015) — modest but real
Ephedrine alone and caffeine alone were NO better than placebo — the synergy between the two is the entire effect (the rationale for the ECA stack)
3RCTn=167 · medium study2002
In this 6-month placebo-controlled trial, herbal ephedra/caffeine (90/192 mg/day) promoted body weight and body fat reduction and improved blood lipids without significant adverse events.
Boozer CN, Daly PA, Homel P, Solomon JL, Blanchard D, Nasser JA, et al. · International journal of obesity and related metabolic disorders (2002)
Six-month randomized double-blind placebo-controlled trial of a herbal ma-huang/kola-nut supplement (90/192 mg/day ephedrine alkaloids/caffeine) in 167 subjects
Herbal treatment beat placebo for weight (-5.3 vs -2.6 kg, P<0.001), body fat, and lipids (lower LDL, higher HDL) — reproducing the modest fat-loss signal
Heart rate rose (4 vs -3 bpm) and there were small blood-pressure changes, dry mouth, heartburn, and insomnia; cardiac arrhythmias were not increased in this trial
Ten events resulted in death, and 13 events produced permanent disability ... The use of dietary supplements that contain ephedra alkaloids may pose a health risk to some persons.
Haller CA, Benowitz NL · The New England journal of medicine (2000)
Mandatory counter-evidence: FDA-commissioned review of 140 adverse-event reports for ephedra-alkaloid supplements (1997–1999)
62% of cases were judged definitely, probably, or possibly related; 47% involved cardiovascular symptoms and 18% the CNS
Hypertension was the most frequent effect, followed by palpitations/tachycardia, stroke (10), and seizures (7); 10 deaths and 13 permanent disabilities
Ephedrine-caffeine compared with placebo preserved fat-free mass and enhanced fat loss, which could be accounted for both by anorexia (75%) and by increased thermogenesis (25%).
Astrup A, Toubro S, Christensen NJ, Quaade F · The American journal of clinical nutrition (1992)
Mechanistic account of how ephedrine/caffeine drives fat loss: acute stimulation of thermogenesis plus appetite suppression
Roughly 75% of the weight effect was attributable to reduced food intake (anorexia) and ~25% to increased thermogenesis — not pure 'fat burning'
Ephedrine+caffeine preserved fat-free mass while enhancing fat loss; caffeine and ephedrine separately had no effect