Homeopathy practitioners say minute doses of substances that cause illness can be used as treatments and highly diluted preparations have a "memory" of the original substance.
The National Health and Medical Research Council (NHMRC) in Australia assessed the evidence of the effectiveness of homeopathy based on 225 controlled studies of homeopathy.
It found no health conditions have reliable evidence of homeopathy causing improvements greater than a placebo.
"Based on the assessment of the evidence of effectiveness of homeopathy, NHMRC concludes that there are no health conditions for which there is reliable evidence that homeopathy is effective," the group said in a report released Thursday.
'Health at risk'
"Homeopathy should not be used to treat health conditions that are chronic, serious, or could become serious. People who choose homeopathy may put their health at risk if they reject or delay treatments for which there is good evidence for safety and effectiveness."
Council CEO Prof. Warwick Anderson stressed health practitioners should always offer treatments and therapies based on the best available evidence.
Headaches, asthma, attention deficit disorder and ulcers were among the medical conditions included in the review.
Homeopathy is not suited to systematic reviews focused on isolated conditions, the Australian Homeopathic Association spokeswoman Ana Lamaro said.
Dr. Brian Morton, chair of the Australian Medical Association’s council of general practice, called for treatments sold without any evidence base to be pulled from pharmacy shelves.