Not sure what happened, but your reply is on the thread three times 
So sorry, I don’t have any idea. I follow a great Holistic Vet on Instagram (also on YT) called Dr. Andrew Jones, perhaps give him a follow.
I don’t KNOW this in a scientific sense, but I believe it based on research I did prior to starting my own cancer protocol: they act in a similar way, and have similar issues with absorption. I found that mebendazole was easier and less expensive to obtain. What clinched it for me was fenbendazole is mostly a veterinary medicine, and I didn’t want to deal with any potential complexities regarding its form and dosage. I have corresponded with cancer survivors who vehemently recommend fenbendazole, so I don’t know. Toss a coin? I’m taking 4 100mg doses daily. The directions say “take with a fatty meal.” I don’t eat fatty meals, per se, so I crush mine with mortar and pestle and take with a tablespoon of high-quality olive oil. I haven’t experienced any toxic effects, but I’d recommend a fiber supplement. One may tend toward constipation, particularly if also doing a ketogenic diet as I am. Note: this is what I am doing; NOT MEDICAL ADVICE!
My post was flagged as “spam”. Greg fixed it but I cannot delete old posts due to the forum system settings.
I like your post! From what I know, Fenbendazole is literally just one atom difference compared to Mebendazole. Perhaps the structure is also somewhat different since Mebendazole can get past the blood-brain barrier and Fenben cannot! So, if dealing with cancer, I would stick with Mebendazole obtained through a licensed compound pharmacy. Pesky cancer cells and cancer stem-cells have the low possibility of getting into the brain.
Also, Fenbendazole is mixed with unknown Inactive Ingredients for most veterinarian supplied pastes and liquids. Supposedly, the only type with GRAS (Generally Accepted As Safe) inactive ingredients is the creamy white paste for horses and cattle, but all the manufacturers keep that list of inactive ingredients secret. It is probably OK, but still an unknown. Also, I would NEVER want to ingest the topical or injectable forms!!!
Personally, I want to support compound pharmacies who are trying to carve a niche-market for making re-purposed human drugs more available at low prices. I took advantage of All Family Pharmacy’s Black Friday BOGO special and now have a whole year’s worth of Mebendazole. Where we funnel our money towards will determine who survives in the marketplace since the U.S. Medical System & Big Pharma are dead set against any of these cost-effective drugs becoming known to the public!
I was actually hoping to hear it from one of the team or Jane.
Hoping these forums don’t continue to fill up with a lot of anecdotal fact-free recommendations - we really do NOT need another form of Facebook-for-cancer.
Apologies @goldenarrow , when I saw your responses in spam, I unspammed them all. I think we’ve trimmed down the additional now…maybe. 
Thank you Greg for cleaning up my repetitive posts since the system did not tell me why they were being deleted. I appreciate that there are controls on the web site to keep things safe from malicious internet hackers and such. Thank you for everything you are doing! 
I can certainly ask the team to see if anyone has an answer for you, and perhaps you could contact Jane on her website https://www.howtostarvecancer.com/
You’re very welcome. Apologies for the frustration. Looks like your posted aren’t being picked up anymore. A good thing.