This meta-analysis was done by the request of the US Department of Health and Human Services. The most comprehensive look at ephedrine for weight loss is a recent meta-analysis published in The Journal of the American Medical Association.

Through nutrient repartitioning, ephedrine promotes fat loss while preserving fat-free mass. It contributes to the release and blocks the re-uptake of the neurotransmitter norepinephrine. This gives norepinephrine the ability to continuously stimulate receptors in your body, causing fat cell "flood gates" to open and facilitate fat loss resulting in weight loss. Not only does ephedrine increase the rate at which fat is lost, it preserves muscle at the same time, making it an ideal dieting aid for athletes. Ephedrine Weight Loss; Can I really lose weight by using Ephedrine products. Ma Huang (Ephedrine) has been shown to increase the effectiveness of thermogenesis (fat burning) in the body. It found that on average, it increased weight loss 1.3 lbs. However, combinations of ephedrine or ephedra with caffeine or herbs containing caffeine resulted in an average weight loss of 2.2 lbs.

It revie 44 controlled trials on the use of ephedrine for weight loss.