As far as I'm aware the beta sitosterol in toco caps is naturally occurring in the palm oil its made from. I take a mixed tocotrienols product too. One could say I don't fuck around. Just for funsies, lauric acid is a 5ari, it also makes up about half of the fatty acids in coconut oil and I consume that in vast amounts. On average about 30-40gms a day. CD likes it too. No issues. Obviously be careful but a tonne of things can inhibit an enzyme in a test tube.. It doesn't always mean consuming that thing will have the same effect after ingestion.