Ordered this via amazon as it was among the best priced available, and did not require me to fill pages of information about my 4 ex-batt hens, one of whom arrived with gapeworm, which is why we bought this product. It is strictly a prescription only medicine, which is why details are requested.
It has needed 2 applications to cure the gapeworm, which is what the product supplier and most other texts suggest. The product arrived promtly and was accurately described. Like many others, i found the small ratio of product to feed (6g to 2kg) very fiddly to do (hence 4 stars), but the 6g measure spoon supplied made it easier.
I would use this supplier again. However, I have since discovered that you can buy Flubenvet at a similar price with no postage from the British Hen Welfare Trust, so would probably go there for this product only.