What are ephedra supplements and are they safe?

Wikipedia describes Ephedra as "both a stimulant and a thermogenic; its biological effects are due to its ephedrine and pseudoephedrine content.[17] These compounds stimulate the brain, increase heart rate, constrict blood vessels (increasing blood pressure), and expand bronchial tubes (making breathing easier). Their thermogenic properties cause an increase in metabolism, evidenced by an increase in body heat."

Wikipedia goes on to say:

"Ephedra is widely used by athletes despite a lack of evidence that it enhances athletic performance. Ephedra may also be used as a precursor in the illicit manufacture of methamphetamine.

Ephedra has also been used for weight loss, sometimes in combination with aspirin and caffeine. Some studies have shown that ephedra, when taken in a regulated and supervised environment, is effective for marginal short-term weight loss (0.9kg/month more than the placebo), although it is unclear whether such weight loss is maintained.[23] However, several reports have documented the large number of adverse events attributable to unregulated ephedra supplements.

Side effects of ephedra may include severe skin reactions, irritability, nervousness, dizziness, trembling, headache, insomnia, profuse perspiration, dehydration, itchy scalp and skin, vomiting, hyperthermia, irregular heartbeat, seizures, heart attack, stroke, or death.