# Honey-Based Medicinal Formulations: A Critical Review
## 4 Discussion
In a randomized controlled trial, it was also confirmed that 90% medical-grade Kanuka honey and 10% glycerin is an effective treatment approach for rosacea [56]. Sage honey, which has been used to prepare a syrup formulation, is made by bees from the nectar of _Salvia officinalis_ or several other types of Salvia. Its high ratio of fructose to glucose sugars make it very slow to crystallize [57]. Sage honey is a good source of antioxidants, and it also contains high concentration of pre- and probiotics, which help in digestion and treating problems in the gastrointestinal tract. Only limited information is, however, available on the bioactivities of other honeys that have been incorporated into formulations, such as 'Honeydew honey' or 'Bulgarian honey'. Given the complexity of honey's phytochemical composition and associated bioactivities, which in many instances are directly related to the honey's floral and geographical origin, such generic descriptions of honeys are not helpful. In this light, claims of effectiveness in wound care made by manufacturers of such honeys need to be treated with caution. Gelam honey (GH) is a Malaysian monofloral honey which is somewhat different to the honeys discussed earlier as it is not produced by European honeybees but from nectar and pollen collected by _Apis dorsata_ bees from Powell (_Melaleuca cajupati_), which is locally known as the 'Gelam tree'. The honey they produce is a popular Malaysian traditional medicine. Several in vitro and in vivo studies have revealed the effectiveness of Gelam honey in wound healing [58; 59; 26]. It is interesting to note that the quality of information provided by manufacturers on the honey in their formulations varies greatly. While some producers stipulate the honey's floral origin, others do not disclose this information, which makes an assessment of the product and a comparison with other formulations less meaningful. Moreover, ingredients other than honey in these formulation also appear to be often not very well documented. Although the reviewed honey formulations have mainly medicinal applications, their standardization, based on publicly available information, appears at best to be limited to stipulating the honey's floral origin and controlling the amount of honey used in the preparation. The exceptions are Manuka honey-based formulations, which often stipulate MGO levels in the preparation. As mentioned earlier, a honey's phytochemical composition, along with the range of its bioactivities, is strongly dependent on the honey's floral source and geographical origin, as well as time of harvest and handling. Ideally, as is commonly the case in quality phytomedicines, a honey-based formulation should, therefore, be standardized to its main bioactive constituent(s), which in turn would allow to better compare different formulations. Given the chemical complexity of honey and the relatively limited data available on the bioactive constituents of these honeys (beyond MGO levels in _Leptospermum_-derived honeys), unfortunately, such a level of quality control might currently be unattainable. However, honey-based formulations should at least be very particular in controlling the quality of the honey used, for instance, by clearly documenting its botanical source, year, and area of harvest. For most of the commercial honey-based formulations, these data are not publicly available and it is impossible to assess if the information is just not released or not collected in the first instance. However, for formulations assessed by in vitro, in vivo, and clinical studies, the honey used in the formulations should be well documented to allow for inter-study comparisons and correlations. In view of the information provided in Table 2, it is concerning that, for most of the studies published to date, this is not the case, with almost half of them not even providing information on the honey itself. The quality of these studies and the strength of their evidence must, therefore, be drawn into question.