“It worked for me” – or do you want evidence?

Dr Ken Harvey
Dr Ken Harvey

Dr Ken Harvey* discusses the current evidentiary requirements for a company to list a complementary medicines. He also suggests where to find information before purchasing or using a complementary medicine.

The vast majority of complementary medicines are classified by the Therapeutic Goods Administration (TGA) as listed medicines (labelled AUST L). Consumers need to be aware of the limitations of an AUST L label. Unlike registered medicines (labelled AUST R) there is no pre-market assessment of listed products. Sponsors self-certify that the ingredients are picked from a TGA  approved list; that the products are manufactured in accord with good manufacturing practice (GMP) and they hold evidence supporting the claims made. Only limited post-marketing reviews are performed by the TGA.

The strength of the listing system is that consumers have some assurance of product quality and protection from unsafe ingredients. It also provides sponsors with rapid market entry at minimal cost. The weakness of the system is that many sponsors exploit the trust-based system. For example, a 2009–10 TGA post-marketing review found as many as 90 per cent of complementary medicines noncompliant with regulatory requirements(1).

The large number of upheld complaints about the promotion of complementary medicines by the Therapeutic Goods Advertising Complaint Resolution Committee provides further evidence of problems(2). The lack of timely and significant penalties for breaches of the Therapeutic Goods Act and the Therapeutic Goods Advertising Code also encourages regulatory noncompliance.

In response to consumer and health professional concerns the TGA has embarked on a 4-year program of regulatory reform(3)It remains to be seen whether these measures will clean up the complementary medicines industry. Meanwhile, what can consumers do?

A survey by the NPS showed that the three most common sources of complementary medicines information for consumers were family and friends, the Internet and health food shop workers.(4) These information sources are of variable quality, reliability and authority.

For example a friend might say, “It worked for me” and product web sites often contain glowing testimonials. But the plural of anecdote is not evidence.

There are a number of reasons why consumers (and practitioners) convince themselves that a treatment is effective when it is not. These include the natural history of disease, the placebo effect, confirmation bias (seeing what you expect to see) and cognitive dissonance (ignoring results not in accord with expectations). Endorsement of products by “celebrities” who receive multimillion payments should raise even more suspicion.(5)

In short, personal evaluation of efficacy is quick, convincing and often wrong, while double-blind, placebo-controlled clinical trials are slow, complex, and costly. However, the latter are important as they often show that initially promising results are not replicated by larger and better conducted studies.(6)

Another common claim implying benefit is that it’s a “traditional medicine” with a long history of use. Traditional use has revealed many useful herbal products such as Artemisia annua for the treatment of malaria and St John’s Wort for the management of mild to moderate depression. But traditional therapies have also proved to be harmful; the bloodletting that was routinely performed for centuries by the medical profession is a classic example. When clinical trials were conducted, bloodletting was shown to kill patients, not cure them. Scientific study is required. The TGA points out that claims based solely on a tradition of use should not imply efficacy. (7)

“Natural” is another advertising claim that implies that these medicines are safer (and healthier) than prescription products produced by Big Pharma.  While it’s true that complementary medicines are relatively low risk products, low risk does not mean no risk. For example, Echinacea can cause allergic reactions, Black cohosh has been associated with rare cases of liver failure requiring liver transplantation and St John’s Wort interacts with a wide range of conventional drugs including oral contraceptives.(8)

Recognition of such problems can be difficult because many patients do not tell their doctors that they are taking complementary medicines and doctors often don’t ask.  In addition, ineffective complementary medicines have a significant adverse effect on consumer’s purses (or hip pockets) and, more importantly, they can delay or prevent the use of more evidence-based therapy.

Another problem is that herbal products consist of a complex mix of chemical ingredients. Just as all red wine is not Grange Hermitage, different products containing the same herb are not necessarily chemically or therapeutically equivalent. Variability can be caused by the use of different species or subspecies, growth conditions, methods of cultivation, the time of year and stage of growth cycle harvested, extraction methods, and formulation and storage of the finished product.

Even glucosamine (used for arthritis) is available as several salts, in many different formulations and with varied evidence of efficacy from clinical trials. (9)

Unlike generic versions of prescription drugs, the TGA does not require evidence of therapeutic equivalence with proven complementary products. As a result, there is no certainty that all formulations of a generic complementary medicine, for example St John’s Wort, are efficacious. Because of this, some complementary therapists sell particular “practitioner only” products that they believe are more likely to be efficacious. However, this practice produces a clear conflict of interest and these practitioners should be asked for the evidence justifying the product they sell.

In summary, if contemplating purchasing an evidence-based complementary medicine:

1. Ask a qualified, registered health practitioner for advice, especially concerning:

          1.1. E vidence of efficacy from well conducted clinical trials concerning the specific product recommended;

          1.2. Possible side-effects and potential interactions with your existing therapy.

2. Search the Therapeutic Goods Advertising Complaint Resolution Panel (TGACRP) web site to see if complaints about a product’s claims have been upheld: http://www.tgacrp.com.au/index.cfm?pageID=13

3. The National Prescribing Service (NPS) has useful information for consumers on complementary medicines as well as over-the-counter and prescription medicines: http://www.nps.org.au/

4. The web site of the U.S. National Center for Complementary and Alternative Medicine (NCCAM), also has a lot of useful information: http://nccam.nih.gov/

5. Keep your knowledge up-to-date; many clinical trials are under way and the evidence keeps changing.

6. Finally, and most importantly, always tell your GP and other health professionals about all the medicines you are taking including complementary medicines.

Dr Ken Harvey for Consumer Health Forum of Australia

Originally published in Health Voices Journal, Issue 11, November 2012.  The link to the original article can be found here.  

Dr Ken Harvey is an Adjunct Associate Professor, School of Public Health, La Trobe University and is a member of the TGA Working Group on Regulatory Reform of Complementary Medicines.



1. Australian National Audit Office. Therapeutic Goods Regulation: Complementary Medicines, 2011.  http://www.anao.gov.au/Publications/Audit

Reports/2011–2012/Therapeutic-Goods-Regulation- Complementary-Medicines/Audit-brochure

2. Therapeutic Goods Advertising Complaint Resolution Committee. Complaint Summary for 2010. http://www.tgacrp.com.au/uploaded/File/ComplaintsSummaryFor2010.doc

3. Australian Government. TGA reforms: A blueprint for TGA’s future, 2011. http://www.tga.gov.au/pdf/media–2011–tga-reforms-111208-a.pdf

4. Williamson M, Tudball J, Toms M, Garden F, and Grunseit A. Information Use and Needs of Complementary Medicines Users. National Prescribing Service, Sydney, December 2008.


5. Sharp A. Kidman new face of Swisse vitamins. The Daily Telegraph, August 31, 2012. http://www.news.com.au/news/nicole-kidman-to-lead-healthsupplement-company-swisses-world-push/storyfnejlvvj-1226462077515#ixzz2674ipl00

6. Rizos EC, Ntzani EE, Bika E, et al. Association Between Omega-3 Fatty Acid Supplementation and Risk of Major Cardiovascular Disease Events A Systematic Review and Meta-analysis. JAMA. 2012; 308(10): 1024–1033. http://jama.jamanetwork.com/article.aspx?articleid=1357266

7. Therapeutic Goods Administration. Consultation: Evidence required to support indications for listed medicines (excluding sunscreens and disinfectants), 27 August 2012. http://www.tga.gov.au/newsroom/consult-cm-evidence-listed-medicines-120827.htm

8. Braun L, Cohen M. Herbs & Natural Supplements. An evidence-based guide. 3nd Ed. Sydney: Elsevier Mosby, 2010

9. Vlad SC, LaValley MP, McAlindon TE, Felson DT. Glucosamine for pain in osteoarthritis: why do trial results differ? Arthritis Rheum 2007; 56: 2267–77.