Original sentence: In addition, most chemical and herbal remedies are not tested or approved by the Food and Drug Administration, so their safety has not been scientifically established.Many products on the market claim to treat the effects of jet lag.Recent research shows that the pineal hormone melatonin may reduce the effects of jet lag.Since the experience of jet lag vary among different individuals, it is difficult to assess the efficacy of any single remedy.Studies have not identified side effects from such short-term use
Edited sentence: It appears to be safe in short term use.Many remedies of various nature are marketed but rarely effective.Recent research shows that a pineal hormone, melatonin, is potentially effective in prevention and treatment of jet lag.Their safety has not been scientifically established