Yes, Tim Ferriss talks about L-Carnitine in the 4-Hour Body.  One would be surprised if he didn’t.  What does Ferriss say about L-Carnitine?

Ferriss notes that carnitine does improve sperm health (specifically, sperm production (spermatogenesis) and motility (motion)), and he is talking about it in the appendix along with his other comments on improving male sex drive.  But has Ferriss completely missed the other benefits of carnitine?

Tim Ferriss also confirms the clinical dosing of carnitine, which is two (2) grams a day.  This is equivalent to 2000 milligrams.  Ferriss does note that he suspects “there are nontrivial effects at doses less than two grams per day.”

At the end of the day, it appears that Carnitine is not one of Tim Ferriss’ favored supplements, even for using carnitine for weight loss.  This is a bit surprising; one would expect him, perhaps, to have done systematic studies differentiating the effects of different types of carnitine, including the difference between acetyl-l-carnitine and L-carnitine.  But Ferriss’ comments do confirm some of the most commonly held views about carnitine (namely, that it occurs the most the redder the meat is and that it helps with male reproductive health.).