When it comes to pain medication, one of the biggest concerns people have is product safety. There are numerous reports of the damage done to health through the misuse and abuse of pain medication. Paracetamol, one of the first products people go to for pain relief is known to be toxic to the liver and in the USA is responsible for almost 50% of all adult cases of acute liver failure, with some individuals experiencing paracetamol toxicity at therapeutic doses (less than 4g per day) (1). The good news is that there are none of these safety concerns with Sigesbeckia.

Ibuprofen is another common and useful pain relief medication, that is classified as a non-steroidal anti-inflammatory drug (NSAID). Like most NSAIDs, ibuprofen is a potent inhibitor of the enzyme cyclooxygenase (COX). COX is the enzyme that facilitates the production of prostaglandins, compounds that are associated with inflammation. Prostaglandins are also however responsible for producing the mucosal layer in your stomach that protects the sensitive stomach lining from stomach acid and consequently long-term use of NSAIDs can lead to heartburn and gastric ulcers (2).  Opiates such as codeine are also commonly used for pain relief, and the addictive properties and side-effects such as constipation are well known for this class of analgesic.  For these reasons, many people are interested in alternatives that may have a more benign safety profile.

How safe is Sigesbeckia?

Sigesbeckia has a long history of safe human usage, and it has been used to treat rheumatic diseases in China for more than a thousand years.  It has also been used in many other countries around the world, including in Europe.  All this points to a good safety profile with efficacy – or else why would people carry on using it?  This information is however what scientists would consider as anecdotal as it is not controlled and compared with a placebo.  A search of scientific databases such as Toxline, Medline, and PubMed shows there are a number of published studies on the toxicology of Sigesbeckia.  Many of these formal studies have focused on the acute toxicity of Sigesbeckia.  Acute toxicity is reported as either the maximum tolerated dose (MTD) or LD50 – the dose that is lethal to 50% of a test sample.   According to international standards published by the Organisation for Economic Co-operation and Development (OECD), if a substance shows no signs of toxicity at doses higher than 5 grams per kilogram of body weight it is considered non-toxic.  Published toxicology studies with Sigesbeckia by various authors have reported MTDs and LD50s between 147 g/kg – 414 g/kg, doses substantially over the 5 g/kg non-toxic threshold.

Sigesbeckia has also been approved as a Traditional Herbal Medicinal Product in the UK.  This registration would have involved substantial review of the safety data in the public domain, as well as any proprietary safety studies performed by Phynova, the company who under took the registration and holds the marketing authorisation.  According to the Summary of Product Characteristics (SmPC), Sigesbeckia extract as used in the licensed product (Phynova Joint and Muscle Relief) has no known side-effects or known interactions with other medications.  It is also part of the Yellow Card scheme, a system run by the UK drug safety watch dog, the MHRA, under which all adverse drug reports or safety concerns are recorded, tracked and based.  If adverse reports are filed, the SmPC for the specific product would be updated to reflect the side-effect, its frequency and severity.

Whilst Sigesbeckia is safe and side-effect free, many other plants are toxic and misidentification of plants can lead to poisoning.  Incorrect handling of plant material, poor quality control and contamination is also a risk with plant based products.  It is for these reasons that the Traditional Herbal Medicinal Product Directive was brought into effect as all products licensed and sold under this category have to do extensive quality checks, including verifying the plant species, and ensuring contaminants such as microbes, fungal toxins, heavy metals, pesticides and herbicides are absent. It is recommended that where possible, licensed Sigesbeckia is used over unlicensed material where provenance and quality cannot be verified.


  1. Amar and Schiff. Acetaminophen safety and heptatotoxicity – where do we go from here? Expert Opinion on Drug Safety, 2007; 6 (4):  http://dx.doi.org/10.1517/14740338.6.4.341
  2. Wallace. Prostaglandins, NSAIDS and gastric mucosal protection: why doesn’t the stomach digest itself. Physiological Reviews, 2008; 88 (4): 1547-1565.