Homeopathy is no more effective in treating health conditions than placebos, a study by the National Health and Medical Research Council (NHMRC) has found.

NHMRC released the findings after assessing 1,800 papers which examined the efficacy of the alternative "medicine".

Homeopathic practitioners believe substances which may cause illness in a healthy person can, in very small doses, treat those symptoms.

They also think molecules in a highly diluted form retain a "memory" of the original substance.

The NHMRC found of the studies examined, only 225 were included in the review, as the scientific quality of other studies was limited.

What is homeopathy? Based on the theory of treating 'like with like', and is supposed to work by giving you very small amounts of substances that in larger doses would cause the very symptoms you want cured.

Based on the theory of treating 'like with like', and is supposed to work by giving you very small amounts of substances that in larger doses would cause the very symptoms you want cured. Taking small doses of these substances – which are derived from plants, animals or minerals – will strengthen the body's own ability to heal and increase its resistance to illness or infection.

Taking small doses of these substances – which are derived from plants, animals or minerals – will strengthen the body's own ability to heal and increase its resistance to illness or infection. Substances contained in homeopathic products are so small they are usually undetectable, but it is argued they still have a biological effect.

Substances contained in homeopathic products are so small they are usually undetectable, but it is argued they still have a biological effect. Homeopathy is used to treat a wide variety of complaints – coughs, colds, depression, headaches, asthma, arthritis – most common day-to-day ailments.

The review found homeopathy was not any more effective than a placebo, or sugar pill, in treating common medical conditions such as headaches, asthma, anxiety, attention deficit disorder, and ulcers.

The council found no study with enough participants which supported the idea homeopathy caused health improvements equal to other medical treatments.

In a statement, NHMRC chief executive Professor Warwick Anderson said that all medical treatments and interventions should be underpinned by reliable evidence.

"NHMRC's review shows that there is no good quality evidence to support the claim that homeopathy works better than a placebo," he said.

"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," he said.

"People who are considering whether to use homeopathy should first get advice from a registered health practitioner and in the meanwhile keep taking any prescribed treatments."

He said the council was aware of the "strongly held" views on homeopathy, and said the review process was consultative, and that the public was invited to submit information and evidence to be considered.

Review 'biased', ignored evidence, homeopathic association says

Australian Homoeopathic Association spokeswoman Ana Lamaro said the NHMRC had already "made up its mind" about homeopathy before the results of the review.

A draft position paper leaked in 2012 showed the council was considering taking a position that homeopathy was unethical, because there was no clinical evidence for its efficacy.

"We call that basically a prejudicial position, and of course they have to find exactly in such a manner or else they would have egg all over their faces," Ms Lamaro said.

Ms Lamaro said studies which showed the effectiveness of homeopathy had been ignored by the council because the NHMRC's overview of systematic reviews meant only studies which were similar enough to each other were included.

She said the varied way that homeopathy was prescribed meant some studies that were not included.

"We're applying the prism of [a] very, very narrow, restricted format of research that applies well to situations where you're testing one drug against one pathological state," she said.

"Homeopathy is a holistic form, meaning we are taking into account the psychosocial, the physical, the emotional state of the person in assessing what they might need medicinally."

She said concerns over patients taking homeopathic treatments and ignoring other medical options were unfounded.

"What's most typical is that patients are receiving advice from a homeopath and a medical doctor or specialist at the same time," she said.

"Patients don't risk their health, patients don't go somewhere where something doesn't work, and pay good money because it doesn't work, patients... act in their own best interests, and this is what they're doing.

"They're seeking out complementary medicine resoundingly across the community, and I think this is what has got mainstream medicine rattled.

"Maybe they can be concerned about that, and maybe they can start to incorporate less harmful modalities in their own practices, and patients and doctors would both be happier."

Doctors call for clear labelling on treatment effectiveness

The Australian Medical Association (AMA) chair of the council of general practice, Dr Brian Morton, said the council's finding was important for the community.

"People can erroneously waste their time and endanger their health by using remedies that they believe will work when they're not evidence based, and it's a waste of money and it's a danger to an individual's health," he said.

"We need to remove from the shelves of pharmacies those treatments that are sold without any evidence base and waste so much money."

"For all treatments, we need... a transparent attitude so people can choose themselves, understand whether a treatment is going to work."

He said the AMA wanted clear labelling on the effectiveness of products claiming to treat medical issues.

Australians spent $US7.3 million on homeopathy in 2009, a World Health Organisation review found.