From my research 450 mg (Fenben) per day seems to be a good therapeutic dose. However, bio availability is tricky. If you take it on an empty stomach, your liver and kidneys sweep it out before any tumor cells see it. Plus it’s fat soluble so I dissolve in oil, along with vitamin E, take after my big meal of the day.
Ran across the following- might be of itnerest to you>?
Update December 2019: A recent study suggests that for Pancreatic Cancer, two other anti-worm drugs from the same category and used in animals, Parbendazol (brand name Verminum, Worm Guard and Helatac) and Oxibendazole, is more effective compared to Fenbendazole and Mebendazole (Ref.). While Parbendazole seems not to be on the market anymore, Oxibendazole can be found online.
https://www.cancertreatmentsresearch.com/fenbendazole/