it's been years since i took them but in the 80's they were the shit.i don't know why i stopped takin them but they do work.thnx for bringing it back to my clouded memory.gonna check some out this weekend.
The late great Vince Gironda was big on these. There is another newer thread right now about some of his principles. There's alot of people who swear by liver tabs.
I took the Ulra 40's by Bev Inter. They work good but it is a pain in the ass to swallow all those big pills all the time. There are now easier ways to get your protein intake up these days.