The NHS should stop funding homeopathy, MPs say.
The House of Commons Science and Technology Committee said using public money on the highly-diluted remedies could not be justified.
The cross-party group said there was no evidence beyond a placebo effect, when a patient gets better because of their belief that the treatment works.
But manufacturers and supporters of homeopathy disputed the report, saying the MPs had ignored important evidence.
It is thought about £4m a year is spent on homeopathy by the NHS, helping to fund four homeopathic hospitals in London, Bristol, Liverpool and Glasgow and numerous prescriptions.
Homeopathy is a 200-year-old system of treatment that uses highly diluted substances - sometimes so none of the original product is left - that are given orally in the belief that it will stimulate the body's self-healing mechanism.
Homeopathy involves giving people very dilute amounts of a substance that in larger amounts might produce symptoms similar to the condition being treated
For example, one remedy which might be used in a person suffering from insomnia is coffea, a remedy made from coffee
Supporters believe the remedies help relieve a range of minor ailments from bruising and swelling to constipation and insomnia.
But the MPs said homeopathy was basically sugar pills that only worked because of faith.
In medicine it is recognised that some people will get better because they believe the treatment they take is going to work.
The MPs said the NHS should not fund treatments on this basis.
They argued the effectiveness was often unpredictable and involved a deception by the medical establishment.
They also warned it could lead to a delay in diagnosis if symptoms were cured but the underlying reason for them was not tackled.
The MPs also criticised the drugs regulator, the Medicines and Healthcare products Regulatory Agency, for allowing medical claims to be made.
The bar for licensing for homeopathic remedies is not set as high as for medical treatments, partly because they have been used since the NHS was set up in 1948 before the current system of regulation was brought in.
Committee chairman Phil Willis said this approval and the fact they were funded by the NHS in the first place lent the remedies "a badge of authority that is unjustified".
But the report acknowledged there was a public appetite for homeopathy with surveys showing satisfaction rates of above 70%.
But the report was disowned by one of the committee's MPs. Labour's Ian Stewart said he was dissenting from the report because the MPs had refused to take into account that homeopathy worked for some people and he also said he was concerned by the "balance of witnesses".
A spokeswoman for the Department of Health said the government would give a full response to the report in the coming months.
But she added: "In the meantime we would reiterate that we appreciate the strength of feeling both for and against the provision of homeopathy on the NHS.
"Our view is that the local NHS and clinicians, rather than Whitehall, are best placed to make decisions on what treatment is appropriate for their patients - this includes complementary or alternative treatments such as homeopathy."
Robert Wilson, of the British Association of Homeopathic Manufacturers, said he was "disappointed" by the findings.
He said the MPs had ignored evidence that homeopathy was effective.
"There is good evidence that homeopathy works, for example in animals and babies, neither of which experience placebo effects."
And Dr Michael Dixon, medical director for the Prince's Foundation for Integrated Health, set up by Prince Charles to promote complementary medicine, disputed the findings, saying homeopathy still had a role in the NHS.
"We should not abandon patients we cannot help with conventional scientific medicine.
"If homeopathy is getting results for those patients, then of course we should continue to use it."
The British Medical Association said it was concerned about NHS funds being used on homeopathy and called for an official review into its effectiveness.