Proponents and opponents

The Cochrane Collaboration Complementary Medicine Field explains its "Scope and Topics" by giving a broad and general definition for complementary medicine as including practices and ideas which are outside the domain of conventional medicine in several countries and defined by its users as preventing or treating illness, or promoting health and well being, and which complement mainstream medicine in three ways: by contributing to a common whole, by satisfying a demand not met by conventional practices, and by diversifying the conceptual framework of medicine.^[92]

Proponents of an evidence-base for medicine^{[n 12][94][95][96][97]} such as the Cochrane Collaboration founded in 1993 and from 2011 providing input for WHO resolutions take a position that all systematic reviews of treatments, whether "mainstream" or "alternative", ought to be held to the current standards of scientific method.^[88] In a study titled Development and classification of an operational definition of complementary and alternative medicine for the Cochrane Collaboration 2011 it was proposed that indicators that a therapy is accepted include government licensing of practitioners, coverage by health insurance, statements of approval by government agencies, and recommendation as part of a practice guideline; and that if something is currently a standard, accepted therapy, then it is not likely to be widely considered as CAM.^[37]

That alternative medicine has been on the rise "in countries where Western science and scientific method generally are accepted as the major foundations for healthcare, and 'evidence-based' practice is the dominant paradigm" was described as an "enigma" in the Medical Journal of Australia.^[98]

Critics in the US say the expression is deceptive because it implies there is an effective alternative to science-based medicine, and that complementary is deceptive because the word implies that the treatment increases the effectiveness of complements science-based medicine, while alternative medicines which have been tested nearly always have no measurable positive effect compared to a placebo.^{[99][100][101][102]}

Some opponents, focused upon health fraud, misinformation, and quackery as public health problems in the US, are highly critical of alternative medicine, notably Wallace Sampson and Paul Kurtz founders of Scientific Review of Alternative Medicine and Stephen Barrett, co-founder of The National Council Against Health Fraud and webmaster of Quackwatch.^[103]

Grounds for opposing alternative medicine which have been stated in the US and elsewhere are:

• that it is usually based on religion, tradition, superstition, belief in supernatural energies, pseudoscience, errors in reasoning, propaganda, or fraud.^{[1][99][104][105]}
• that alternative therapies typically lack any scientific validation, and their effectiveness is either unproved or disproved.^{[99][106][107][dubious – discuss]}
• that the treatments are those that are not part of the conventional, science-based healthcare system.^{[25][53][108][109]}
• that research on alternative medicine is frequently of low quality and methodologically flawed.^{[110][full citation needed]}
• that where alternative treatments are used in place of conventional science-based medicine, even with the very safest alternative medicines, failure to use or delay in using conventional science-based medicine has resulted in deaths.^[111][112]
• that methods may incorporate or base themselves on traditional medicine, folk knowledge, spiritual beliefs, ignorance or misunderstanding of scientific principles, errors in reasoning, or newly conceived approaches claiming to heal.^{[99][104][113]}

Paul Offit has proposed four ways in which "alternative medicine becomes quackery":^[49]

1. "...by recommending against conventional therapies that are helpful."
2. "...by promoting potentially harmful therapies without adequate warning."
3. "...by draining patients' bank accounts,..."
4. "...by promoting magical thinking,..."