MediHerb was co-founded by Kerry Bone, a first class honours graduate of Melbourne University who won the Masson Memorial Prize as Australia’s top Chemistry student. Whilst working as a research scientist, Kerry studied naturopathy at the Southern School of Natural Therapies for two years before deciding to relocate to the UK to study phytotherapy in-depth.


Upon completing the four-year Diploma in Phytotherapy from the world renowned School of Phytotherapy in England, he returned to Australia to practice. However he became increasingly frustrated with the poor quality of herbal extracts available at that time and the resulting effects for his patients. By applying his scientific training he developed a unique method of extraction, termed 1:2 Cold Percolation. Word of these high quality herbal products spread and requests were soon received from health care professionals for supply around Australia and so MediHerb was born.


Why 1:2?

When MediHerb co-founder Kerry Bone was a student in the UK in the early 1980s he developed concerns that the predominant use of 1:5 tinctures and even weaker fresh plant tinctures, was resulting in patients receiving subtherapeutic doses. However, the 1:1 fluid extracts available at the time were industrially produced and poor quality, mainly due to the use of the excessive heat in the concentration step employed during the manufacturing process. Even worse, many 1:1s were made not from the dried herb, but by diluting concentrates of dubious origin. He realised that there needed to be a compromise: a galenical liquid that reflected the minimal processing of a 1:5 tincture, but was much stronger so that clinically effective doses could be achieved. After much deliberation he arrived at the solution: 1:2 extracts made by cold percolation. When used in a formulation with a dose of 5 mL TDS, therapeutic doses could readily be achieved. This innovation provided the cornerstone technology which led to the development of MediHerb. For more information on this topic and that of herbal dosing see the discussion in his book: A Clinical Guide to Blending Liquid Herbs.


MediHerb Manufacturing Processes and Quality Control for Herbs

This chart follows on from the Quality Assured Sourcing of Herbs process, which is featured on our Quality Assurance page


Quality Control Herbs


Unique Extraction: 1:2 Cold Percolation Process

The MediHerb 1:2 Cold Percolation method is unlike other herbal extraction processes; no heat or concentration is used, both of which may cause damage to the delicate plant material. The greatest care is taken to prevent any contamination from outside sources throughout the extraction process:


  • All extraction equipment is designed and built from stainless steel
  • Air used in the manufacturing complex is thoroughly cleaned using pharmaceutical standard filtering units


In addition to the herb itself, we use only two other raw materials in manufacturing our herbal extracts, ethanol and purified water. Both are chosen very carefully to ensure the most efficacious product and meet pharmaceutical standard specifications.


All process water used in extraction is purified by reverse osmosis. First, it is filtered through numerous filter beds to remove particulate matter and organic compounds, then passed through reverse osmosis cartridges to remove the ionic materials before finally passing through an ultra-fine filter. The water produced is very low in all contaminants – organic, ionic and particulate – and is tested to comply with the British Pharmacopoeia specification for purified water BP2011.


1:2 Cold Percolation - no heat or concentration, therefore 
no damage to the herb's constituents


Silybum Marianum

MediHerb only uses ethanol that complies with the British Pharmacopoeia specification for ethanol, BP2011. Ethanol is essential to extract the full phytochemical profile of the plant, this cannot be achieved using water or glycerol alone. Ethanol has been used for hundreds of years in herbal extraction and old herbal texts discuss steeping herbs in wine over long periods. The human liver is naturally conditioned to metabolise small amounts of ethanol from ripe fruit and naturally fermented food. Any toxic effects from ethanol are dose-related and there is minimal risk of potential ethanol toxicity with herbal extracts due to the low daily dosage required. The usual recommended dose of most 1:2 herbal extracts is only 5 mL three times per day and in 5 mL there is approximately the same amount of ethanol as 1/6 of a standard glass of beer or wine.


Through our scientific analysis MediHerb has chosen specific ethanol percentages for each herb to maximise the quality, for example 25% ethanol extracts of St Mary’s Thistle will not contain any silymarin because it is insoluble at this concentration.